training course dox
DESCRIPTION
this course contains my experience as a field engineer in the field of instrumentation, electrical and mechanical maintenance. i would like to share it with anyone who want to be maintenance engineer.TRANSCRIPT
This training course is aiming to introduce Gastec to any entry level engineer. In order to
develop his knowledge about the company’s field as quick as possible. Not only in his specialty but
about Gastec’s CNG field as whole
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Acknowledgements
First I should thank Allah that gave me this kind of opportunity to learn all what I’ve learned through my training period in GASTEC
I am grateful for my entire supervisor Eng. / Ayman Ramzy and Eng. /Reda Ahmed for their assistance and support in order to finish this training course
I would like to thank every Engineer and technician who taught, showed or explained a single detail about anything in the company’s Field
Special thank to Eng. Mohamed saad & Eng. Amro Hassan for their mechanical support. Also to my colleges who shared with me their knowledge about every single detail in our work.
Special thank to Eng. Mohamed Koutb for his detailed assistance to me in all the electrical devices’ troubleshooting. Also how understanding and tracing any troubleshooting.
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1. Introduction
1.1 Gastec:
It is a company that works in the field of the CNG “compressed natural gas”. It works on supplying the cars
with natural gas on 220 bars. It takes the natural gas the network at medium pressure to convert it into
high pressure gas that is suitable to be reserved in a cylindrical tank in the car. Not only it supply the gas
but also it assembly the conversion kit and plug it to the cars.
Gastec considered being the Pioneer of using the natural gas as cars’ fuel. It has now over 42 stations all
over Egypt with a plan for expansion every year.
1.2 Natural gas:
Natural gas is a mixture of hydrocarbon volatile gasses, Methane is the CH4 and its percentage varies from
80% to 96%. This percentage varies from a field to another. In addition to another components
Ethane 4%
propane 0.03%
Butane Negligible percentage
Nitrogen Negligible percentage
CO2 Negligible Percentage
Thereby Methane is the most effective in methane properties in the natural gas. That is why they call the
natural gas Methane
There are to main types of gasses that have been used CNG “Compressed natural gas” LPG “Liquefied
petroleum gas”. In cars we use CNG which is withdrawn from the network at 2.5 bar and charge the cars
with 220 bar, while in home use there are the cylinders that contains LPG which are a mixture of
compressed petrol, with mainly propane and butane gas as main component .
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1.3 Natural gases Properties and Calorific value compared
to benzene
Fuel type Density (Kg/m3) Calorific value (MJ/Kg)
CNG 0.73 48
benzene 720-780 43
Diesel 820-950 42
1.4 Natural gas mining:
1st method:
You harvest the gas alone without any accompanied oils and that called Gas Well, and it is the main
method of gas mining.
2nd method:
You harvest the gas with petroleum oil, and that gas is produced because of the high temperature and
pressure inside the earth’s layers. And that gas is called associated gas.
1.5 Natural gas properties:
1. The natural gas has a property of being less dense that the air. Its’ density is 0.73 kg/m3 under sever
condition which is 1 Bar and temperature 15 Degree, that leads to its escape to the higher level of the
earth’s atmosphere. That minimizes its ignition probability.
2. The natural gas doesn’t ignite except under high concentration percentages with high temperature level
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2. Station Main components
1. Mechanical Equipments
2. Electrical & control Equipments
3. Piping and instrumentation
2.1 Electrical & Control Equipments
2.1.1 Driver
There are two types of drivers in use:
2.1.1.1 Internal combustion engine, a caterpillar six cylinder gas engine is used in Haya’a
station.
2.1.1.2 Electrical induction motor, there is many companies produce the induction motors
starting from ABB, Siemens and Baldor, we use the induction motor for its wide torque
speed characteristics. Their power range for the driver we use from 150 Hp to 300 Hp
How to order a Driver
When you are going to select a drive there are two perspectives you should consider firstly the electrical
perspectives then the mechanical specifications
Electrical specifications:
Efficiency of the motor, HP range, Frame Size, Frequency, Power, Voltage, service factor
(sine wave) “i.e. 1.15”, electrical design “i.e. NEMA – design X”, stator winding copper
winding, insulation “i.e. Class F, meets NEMA MG1 – 2003 Part 30”, Temperature rise (sine
wave) “i.e. class B @ 1.0 SF ”
Mechanical specification:
Frame’s material, Conduit Box, lead seal gasket “Neoprene”, Cooling fan “140-440
Bidirectional, polypropylene 5440 locked & keyed bronze”, bearing type “single shielded*”,
rotors material “Die cast Aluminum”,
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2.1.2 Main Electrical panel
It consists of Main circuit breaker in the range of 630 A. there is a phase sequencer because some time
after the electrical cut the three phase sequence return in a reverse phase order so the phase sequencer
trip the circuit breaker, there is also a manual breaker with two ways to connect in order to over come
this event. This panel had fully designed and stated its own
specification by Eng Moneer Elnawawy
2.1.2.1 Circuit breaker:
Mainly we deal with Marlin Gerain or Cutler
Hammer, but there are other types that are
in use. There are shunt trip terminals that
are connected to the phase sequencer to cut
the circuit of in case of any up normal
condition. Also on its inputs there a current
transformer to transmit the value of the
current to the phase sequencer as we see in
the picture
How to perform the setting of the circuit breaker*
You calculate the current that is going to be
with drowning by the equipments. Then
2.1.2.2 Phase sequencer
Its name is usually SAMMO EOCD “3DI, 3DF, 3DS, 3DM” this
kind of series are analog which have dip switch for settings
while 3DE is the digital series, its main sittings nominal current,
O.t “Starting current”, D.t “delay time of fault”, Phase reverse
“-RP-”, PL “Phase lose”, Ub “unbalance”, locked rotor
protection Alarms, there are types that display a relative
current according to the transformation ratio of the
transformer
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I.e. if the transformation ratio is 600/5=120 and the displayed current is 2 that means
that the actual value is 240 A, there another types that display the actual value
Specification could be known from the model
i.e. EOCR – 3DI 05 440
3DI digital inverse time type multifunctional current relay
05 is the current adjustments which indicate that it have current from 0.5 to 5
A while it could be 60 that indicates current from 1.6 to 8.6 A
440 is the operating voltage that is within range 180 to 480 V, also it could be
20 that indicates working voltage within range 90 to 260 volt.
Event:
There was a repetitive fault that happen in Helwan station they all thought it is
overload at first but when Koutb went there he discovered that the fault was not an
over load fault it was unbalance fault since the air compressor was taken from the
compressor contactor and it take about 15 A and since the permitted range of the
unbalance is 20 A he set a new setting with phase unbalance 35 A and the job is done
2.1.2.3 Manual Breaker with 2 ways to connect, this breaker is used to switch the phases since
there is some time when a cut off occur and there is a recovery in the line the phase
sequence is reversed, in order to shame this reverse we use this breaker
Supply
220 or 380 Shunt trip
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Event:
While we were making a run test on the motors of Manar station, we found that the
motors rotates anti clock wise so we reversed this hand in order to restore the right
rotation, but if not all the motors were the same , we should have reversed the phases
of the reversed motor. Take care also that it is not a must to have the rotation clock
wise or anti clock wise it is according to the flow and the fan angle
2.1.2.4 ESD “Emergency Shut Down” this a normally close switches that
exist in the circuit to shut the circuit down in case of any up
normal condition by cutting both of the AC “110” and DC “24”
from all the circuit, since it is a normally close switches so when
we are connecting more than one switch, we connect them in
series. While in case of normally open switches “i.e. starts push
button” we connect them in parallel. The data sheet of this model
you will find it in the appendix.
Event:
While I was in MANAR site there was an ESD push button that is
normally close and due to the glass is normally pushing it will stay
open, Mohamed salah the technician said to me that we will
connect it on the normally open sitting and due to the glass it
always closed in case of emergency anyone will break the glass
and the push button will be released opening the circuit.
2.1.2.5 Power factor corrector panel is a panel
consists of sets of capacitor banks that log
as sets to correct the power factor in order
to reach unity to reduce the consumption of
reactive power. It consists of 8 capacitor
sets (fuses 50 A strike, power factor
regulator, and FRAKO 20 KVAR capacitors).
Event:
At kalub station there were some sits of the capacitor
banks broke down, also there were some sets had there fuses broke down
so they replaced the fuses and the system restore its state “you could know that the
fuse is broken down from an indicator like a paper in the top of it”
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2.1.3 Auxiliary panel
2.1.3.1 Main motor contactor
2.1.3.2 Power supply
The controls’ systems don’t work with
alternating currents, also due to that most
of our systems are American, which work
on 110 VAC. While for the control circuit
you need 24 VDC. So you need a power
supply to supply both of those circuits.
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2.1.3.3 Insertion module
When the compressor fall down for a certain Emergency stop and we need to operate
it once more we use this button in order to force it to start.
2.1.3.4 Barriers
They are used as buffers between the sensors in the hazard area and the PLC as a
protection for PLC at mean while it reduce the current used by those sensors in order
to avoid formation of the spark inside the hazard areas.
2.1.3.5 Gas detectors.
Those modules are used to detect the gas leakage
in case of closed areas or enclosures.
2.1.3.6 Auxiliary motors contactors the are the contactors
that is responsible for the operation of the auxiliary
motors such as water pump, oil pump, air
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compressor and air extractor “in case of enclosure” ………etc.
2.1.3.7 Auxiliary motors thermal protection it is a kind of protection to each motor.
Event: “Helwan station”
In case there is a fault in a certain motor of these motors you will find the thermal
contactor turned on off position, they reported auxiliary motor run fault and before
Eng. Koutb reaches the station the make a reset that made him not able to identify
which motor that made the fault
2.1.3.8 Inverters “vacon frequency inverter”. It consists of two main unit units’ power and
control unit. It is three phase AC choke(1) at the main end together with the DC-link
capacitor (2) form an LC-filter, together with the diode bridge “half wave rectifier”
produce the DC-voltage supply to the IGBT inverter bridge (3) block. The AC-choke also
functions as a filter against high frequency disturbances from the mains as well as
against those caused by the converter to the mains. In addition to enhances the
waveform of the input current to the frequency converter. The entire power drawn by
the frequency converter from the mains is active power; the IGBT inverter bridge
produces a symmetrical, 3-phase PWM- modulated AC-voltage to the motor.
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High overload: Max current Is, 2 sec/20 sec, 150% overload ability, 1 min/10 min following
continuous operation at rated output current, 150% rated output current for 1 min, followed by
a period of load current less than rated current, and of such duration that the r.m.s output
current, over the duty cycle, doesn’t exceed rated output current
Low overload : Max current Is, 2 sec/20 sec, 110% overload ability, 1 min/10 min following
continuous operation at rated output current, 110% rated output current for 1 min, followed by
Frequency converter type
load ability Motor Shaft power
Low high 380V supply 500V supply
Rated Continuous current IL
(A)
10% Overload current
(A)
Rated Continuous current IH
(A)
50% Overload current
(A)
Max. Current
Is (A)
10% Overload
40⁰C P(KW)
50% Overload
50⁰C P(KW)
10% Overload
40⁰C P(KW)
50% Overload
50⁰C P(KW)
NX 0590 590 649 520 780 936 315 250 400 355
NX 0520 520 572 460 690 828 250 250 355 315
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a period of load current less than rated current, and of such duration that the r.m.s output
current, over the duty cycle, doesn’t exceed rated output current
Break resistor ratings
Converter Type Max. brake Current Resistor nom. (Ohm)
NX 590 855 0.9
NX520 570 1.4
Control characteristics
Control method:
Frequency control V/F
Open loop sensor less vector control
Closed loop vector control (NXP only)
Switching frequency
From 1 to 6 KHz : def: 3.6 KHz
Control connections
Analog input voltage:
0..10V, R=200KΩ
Analog input current
0(4)…20mA, R=250 KΩ
Analog output
0(4)...20mA, RL =500 Ω
2.1.3.9 Star-delta starters , usually we start induction motors as star connected then change it
to delta connected, That is due to the low withdrawn current in star connection with
respect to that of the delta connection, this scheme is usually used in weather ford and
JW systems
2.1.3.10 Soft starters* like those Siemens soft starters that exist in the safe’s SW old systems
they are inverters that starts the circuit and after that they make internal bypass
2.1.3.11 Lighting arrestors are usually used even though Egypt doesn’t considered to be a
country that have a weather that have probability of lighting surges a lot , this lighting
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arrestors should be placed higher that the highest construction in the station and it is
connected to the earth electrode
Important concepts:
1. Earth it is smallest resistance in the field and it is maintained by digging a hole in the field with
electrode and coal around it in order to minimize the resistance as much as possible. Usually it
defined in manuals as an equipotential collector and it is assigned with PE symbol. and this
2. Neutral is the line that is assigned with the alternating current generation where the unbalance is
dissipated in it “Zero current”.
3. Ground is another name for the neutral.
4. Types and sizes of cable are as follows 35, 50, 70, 95, 120, 150, 185, 240, 300mm there are some
types of cables that contains the three phases with each other at the same cables and the ground
terminal that is usually half the area of one phase, Other method to act as an equivalent method is
to have a cable or more for each phase and a ground with area approximately half of one phase.
5. There is another categorization for cables. There are solid cables and strands. We usually use
stranded wires for more flexibility
6. Loading factor is a ratio between the current and the area passing in it, selecting this loading factor
depends on many parameters such as heating and transmission medium, we usually use it 2 A for
every 1 mm²
7. Main concept of starting:
o Direct-on-line (DOL) starters
With this type of starter, the stator windings of the motor
are connected directly to the three phase mains supply.
The motor starts and accelerates in a way determined by
its own characteristics. Typically, the peak starting current
is between 5 and 8 times normal full-load current, and the
peak starting torque is between 0.5 and 1.5 times the
motors nominal operating torque.
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Although DOL starters offer a number of advantages, including simplicity, low cost and high starting torque,
their use is limited to applications where:
Low-power motors are being used, and the supply capacity is high, so that the starting current
surge does not adversely affect other equipment using the same supply
The equipment driven by the motor is fitted with a gearbox or some other device which will soften
the mechanical shock produced by the high starting torque
A high starting torque is needed - for example, the equipment starts against its full mechanical
load.
When the limitations of DOL starting are not acceptable, it is necessary to use alternative starting
techniques which reduce the peak starting current and, therefore, the peak starting torque. The normal
approach is to arrange for the motor to be started at reduced voltages, and a number of methods have
been developed for doing this
DOL starting are not suitable when:
The peak starting current would result in a
serious voltage drop on the supply system.
The equipment being driven cannot tolerate
the effects of very high peak torque loadings
The safety or comfort of those using the
equipment may be compromised by sudden
starting as, for example, with escalators and
lifts
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o Star-delta starters
This type of starter may only be used where access is possible to both ends of all three stator windings.
In addition, the windings must be rated to withstand the full supply voltage when delta-connected. With
star delta starting, the peak starting current is typically between 1.5 and 2.6 times the normal full-load
current, and the peak starting torque is between 0.2 and 0.5 times the motor's nominal operating
torque.
On starting, the supply is first applied to the motor with its stator windings star-connected. As the motor
accelerates, its speed stabilizes when its developed torque become equal to its load torque. This usually
happens at about 75% - 80% of nominal speed. The star contactor is then De-energized, and the delta
contactor is energized to delta connect the stator windings. Each winding is now fed with the full supply
voltage, and the motor adopts its normal operating characteristics.
The run-up time with the windings star-connected is controlled by a timer which, typically, can be
adjusted from 0 to 30 seconds. This timer is adjusted during commissioning to ensure that the star-delta
changeover occurs, as closely as possible, at the point of torque equilibrium. The transition time from
star to delta is also important, and a special timer is normally used to ensure that there is a period of
between 30ms and 50ms between the opening of the star contactor and the closing of the delta
contactor. This allows time for any switching arcs to be extinguished.
Star-delta starters are particularly suited to machines which do not present a high load torque at start-
up, or which normally start off load. It is also important to note that, during the star-to-delta transition,
a high transient current is generated. If a magnetic short-circuit protective device is to be used in the
starter, this transient must be taken into account in the selection of the device, in order to prevent
nuisance tripping.
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Although the transient produced at the star-delta transition is very brief, the current can be quite large
and, particularly for larger motors, some form of current limiting may be necessary. One solution is to
introduce a delay of 1 to 2 seconds during the star to delta transition. To avoid too large a speed drop
during the transition, however, this method can only be used
with low-inertia loads.
o Electronic soft starters
This relatively recently introduced form of starter is rapidly
growing in popularity. Soft starters operate by gradually
increasing the voltage applied to the motor, so as to produce
steady, smooth acceleration. This technique eliminates
sudden changes in voltage which could produce peaks in
both starting current and torque.
The steadily increasing supply voltage for the motor during
starting is produced by a thyristor bridge which, in each
phase, has two thyristors connected back-to back. By varying
the firing angle of each set of thyristors, it is possible to
control the starting voltage and, hence, the starting current.
Note that, unlike inverter drives, soft starters do not vary the
frequency of the supply to the motor. The detailed design of
soft starters varies from manufacturer to manufacturer,
Control of the acceleration and deceleration ramps of the
motor in such a way as to keep within all required limits on
current and torque
Thermal overload protection for itself, and for the motor which
it is controlling
Mechanical protection for the machine being driven, by eliminating sudden changes in current -
and, therefore, torque - during starting and stopping.
The peak starting current may be adjusted between 2 and 5 times nominal full-load current,
corresponding to a range of starting torques from 0.1 to 0.7 times the starting torque which would
be produced if the motor were started with a DOL starter.
o Speed regulation of asynchronous motors
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While speed regulation, strictly, goes a little beyond motor starting, the two subjects are so closely
related that a brief discussion of speed regulation is included here for the sake of completeness.
For many years, the scope for varying the running speed of asynchronous motors was rather
restricted. Only motors with pole-changing facilities, and those with separate windings, were
popular for applications requiring multi-speed operation, but even these types could only operate at
one of a number of fixed speeds. This situation changed dramatically with the introduction of
frequency inverters which allow the running speeds of standard motors to be accurately controlled
over a wide range. Inverter technology is so successful that AC inverter drives are now being
adopted for many applications where, in the past, only DC machines, with their inherent ease of
speed control, would have been suitable.
While various methods of speed control are possible, which use only conventional components
such as contactors and resistors, these methods are fast becoming obsolete as they are replaced
by inverter systems this supplement will, therefore, deal principally with speed control by inverter?
o The frequency inverter drive
This type of drive is intended mainly for use with three-
phase squirrel cage motors. It operates by using a
technique called pulse-width modulation (PWM) to
synthesize a sinusoidal waveform, the frequency of
which can be varied, that is used to supply the motor. By
varying the frequency of the supply to the motor, the step
less motor speed variation is possible over a wide range.
Since the synthesized supply waveform is very close to sinusoidal, smooth motor rotation is
achieved even at low speeds.
o Inverter drive operation
The AC supply (single or three phases) to the inverter is rectified by a full-wave diode bridge, and
is used to charge the main reservoir capacitors.
This provides the system with a high-voltage DC source which is then switched by the output
power bridge to produce a pulse train made up of precisely controlled long and short pulses. The
train of pulses produces a sinusoidal current in the motor, the voltage and frequency of
Variable speed “soft-starting” Star-delta Direct-on-line
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1.8 In for 200 ms Adjustable, 2 In
to 5 In
1.3 to 2.6 In 4 to 8 In Peak starting
Current
1.7 Tn Adjustable, 0.1 to
0.7 Tn
0.2 to 0.5 Tn 0.6 to 1.5 Tn Peak starting
Toque
Variable Gradual On or off On or off Control
• Parameters are
fully adjusted
during
commissioning
• Compact
• Solid state
• Easily adapted to
the application
• Infinitely variable
speed
• In-built motor
protection
• Low starting
current
• Parameters are
fully adjusted
during
commissioning
• Compact
• Solid state
• Easily adapted
to
the application
• Simple,
economic
starter
• Good starting
torque/current
performance
• Simple starter
• Low cost
• High starting
torque
Advantages
• Can cause
interference on the
supply
• Can cause
interference on
the
• Low starting
torque
• Non-adjustable
• Very high
starting
current and
Disadvantages
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• Relatively
expensive
compared to
direct-on-line
supply during
starting and
stopping
starting
parameters
• Break in
supply to
motor leads to
severe transient
peak current
torque
• Supply must
withstand peak
current
• Mechanically
harsh
starting
sequence
0.1 to 999 seconds Adjustable, 1 to
60
seconds
3 to 7 seconds 2 to 3 seconds Run-up time
• All machines
where speed
needs to be varied
to improve
production and
reduce mechanical
wear
• Machines where
energy can be
saved by reducing
speed (centrifugal
• Machines
requiring
very smooth
starting
(centrifugal
pumps and fans,
Conveyors, etc.)
• Machines
starting
on no-load
(small
centrifugal
pumps,
Fans, etc.)
• Small
machines
may often be
started on full-
load
Typical
applications
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This can be accurately controlled. By retaining the correct voltage/frequency ratio in the
Supply to the motor, its torque can be maintained over a wide speed range.
What is IP protection?*
Tracing in the power circuit
Hypothetically you are the electrical current, first you will pass through set of fuses with range around 500
A. afterwards there is a main cross way. One of them leads through a soft starter to the motor. While the
second leads to the power supply on the auxiliary panel that distribute it to the auxiliary motors and the
PLC power supply “24 VDC”.
How to read an electrical manual?
*
2.2 Mechanical Equipments
We will discuss the mechanical component from the packagers’ point of view. Mainly they are two main
types horizontal reciprocating “J.W., W.F., Kraus” and radial reciprocating “Safe”. Also there are many
categorization from the suction point of view there is some station that works on suction from 2-4 that
called low suction station, there some that works on suction from 4-6 that are called medium suction
station while there are some station that works on suction from 24-30 that are called high suction
stations.
Hint:
According to the European standards “Safe” the number that indicates the power of the driver is in Kilo
watt whether the American standards are in Horse power.
Safe compressors
There are 3 main types of safe compressors:
Pumps, fans, etc.)
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1. The SW series i.e. SW200F6-EM-1/6. Which means 200 KW, suction 6 bars; Electrical motor, 1/6 is
the stroke.
2. The ST series i.e. ST65T26-1N90-EM, which means 65 KW; this kind of compressor has two oil circuit.
3. The SX series i.e. SX, Relatively large flow rate.
Weatherford, JW “Gemini” and Kraus “Arial” compressors
There are different types of compressors:
1. There is types that has all the stages on two shafts
2. There is types that has the stages on 4 shafts as shown in figure, but one of the major
disadvantages of this compressors is that any trouble in 3rd stage of A or B means a trouble in the
corresponding 4th stage
There is another categorization from the flow point of view
Hint: this mechanism has nothing to do with single acting and double acting mechanism, because double
acting means that it compress I both direction, that will be explained later, and this technique called
double cylinder
Example:
1. H302/G3306 N/A, 02 means to shafts, G means gas combustion engine, 06 means no. of the
cylinders, N/A means natural aspiration.
2. H304/ELECT 250, 04 means 4 shafts, ELECT means electrical motor ,250 hp
Horizontal reciprocating compressor clearance pocket:
Clearance pocket exist to vary the compressors’ output flow rate, as you increase the volume of the first
stage the flow rate decrease, since during the compression process will remains some compressed gas in
the end of the stroke so it will need to expand this gas first as the piston go away in order to open the
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inlet valve since the valve will open just in case of the inside pressure less than the outside in to intake
the gas for the second compression.
Components and theory of operation of the reciprocating compressors
Main Components
Crank Shaft: it is the prime mover for all the compressor parts and it is operated by external
mover that could be internal combustion engine of electrical motor
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Connecting Rod: it is the part that responsible for the transmission process of the rotational
motion of the crank shaft to a linear motion.
Liner & cross head: the motion that is produced by the connecting rod is random that is why we
use the liner & cross head to organize this motion to uniform linear one.
Piston: it is connected to the cross head to transmit the motion plus piston rings to prevent the
gas leakage.
Cylinder head: it is the part of the compressor at which the compression process occur where is
the valves exist
Valves: there is two types of valves there is inlet valves and out let valves, also there is types of
valves that consists of both inlet valves ”Suction” and outlet valves “Discharge”.
Packing:*
General theory of operation
For simplicity, when the electrical motor rotate the crank shaft, the crank shaft rotates gives random
motion, here comes the role of the cross head and the liner to organize it and make the motion
uniform linear reciprocation motion, this motion is transmitted to the piston which is connected to the
cross head, In order to make the stroke from the top dead point to the lower dead point.
The previous explanation was for a simplicity process of one stage. So in case of high pressure
difference between the output and the input, we will use multistage compressor.
Also our compressor varies according to the station sites, since the input to this compressor comes
from the Egyptian gas’s network which varies according to its’ use home or industrial so the suction
varies from 2-30 bar but the most common working pressure is 6 bar.
The four stages are approximately like follows.
1st stage 4-20 bar.
2ndstage 20-60 bar.
3rd stage 60-120 bar.
4th stage 120-220 bar.
The suction process occur as follows when the piston moves from the top dead point to towards the
bottom dead point the volume inside the stage increase and the pressure decrease till the inside
pressure is less than the outside pressure so the suction valve inlet the gas. Then when the piston is
moving from the bottom dead point towards the top dead point the pressure inside become larger
than outside since the volume decreases, that makes the outlet valve discharge the gas inside the
stages.
2.2.1 Weatherford compressor operation
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2.2.1.1 compressor
When the switch is set on “Automatic”, the PLC revise all pressures inside the Air tanks to
insure that it didn’t fall under a certain level that secures a total control on the actuator valves.
Also in case of the falling of the air’s pressure under a certain level the PLC gives it a signal to
restore the pressure.
The pre lubrication operation comes immediately after the air’s pressure check stage. Where
there a signal sent to air solenoid that sent air with pressure 2- 5 bar to the pre lubrication
hydraulic piston to insure that the oil reaches critical points then after a certain period “30
sec” the oil’s pressure increase then the hydraulic piston restore its position and the solenoid
ventilate the air in the piston.
After the pre lubrication process the PLC send three main signals, the first one to open the
suction actuator to begin the worm up process, when the worm up process ends the second
signal goes to the bypass actuator to close it and opens the Discharge valves.
After closing the bypass actuator the gas comes from the suction regulator to the scrubber for
separation of the condensate then it goes to the gas filter for purification process then the gas
goes to the pressure regulator to regulate it.
After the gas increase its pressure in the first stage it exits to a scrubber to separate the
condensate impurities that result due to the compression process afterward to a cooler. To
condensate the heat compression effect. Then to the second afterward to the third finally to
the fourth stage. The gas exits the last stage with pressure 240 bar at least.
When the compression process ends after the banks reach its’ full pressure, the PLC gives a
signal to open the bypass and close the discharge valve to entre the cool down process. At
mean while it keep monitoring the delta bank pressure, in case the pressure falls down, again it
starts to work again to compensate the delta pressure. If the banks pressure don’t fall the PLC
gives 2 signals one to close the suction valve and the second to the motor to shut it down.
2.2.1.2 Lubrication cycle
Lubrication cycle components
1. Gear pump: it is a oil pump that is coupled with the crank shaft
2. Block divider “spider”: that divide the oil to lubricate the stages parts
3. Plunger Piston
4. Pre lubrication piston
5. Oil filter
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6. Compensation tank
7. Oil level switch
8. No flow switch
9. Cooling unit for the gases
10. Check valves
Theory of operation
As explained previously, the pre lubrication operation comes immediately after the air’s pressure check
stage. Where there a signal sent to air solenoid that sent air with pressure 2- 5 bar to the pre
lubrication hydraulic piston to insure that the oil reaches critical points then after a certain period “30
sec” the oil’s pressure increase because the oil pump is coupled with the crank shaft then the hydraulic
piston restore its position and the solenoid ventilate the air in the piston.
When the oil pressure increase the oil’s pump push the oil to the plunger pump, that compress the oil
to a higher pressure, also it send it to the cylinders and packing through the divider block, and the
check valves insure that the oil won’t return back
2.2.1.3 Cooling circuit
The cooling component in the station:
1. Gas air cooler : It is the same as the car radiator
2. Forced Cooler Fan: it is a huge fan coupled with the crank shaft in the 600 m³/hr or drove by
electrical motor like those of 1200 m³/hr stations
2.2.1.4 Sequential panel
It is a panel that contains a number of solenoid that are controlled through the fill minder card in order to
organize the filling process according to the appropriate sequence
2.2.1.5 Dispensers
It is the machine, through which the car filled with gas, and it has a flow rate of 10 m³/hr, the dispenser
main components are as follow:
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1. Computer unit “MODEL 33”
2. Micro motion transmitter
3. Mass flow sensor
4. Control valves
5. Fill minder card
6. LCD display
7. Fueling hose “Break away connection, Short hose, three way valves, refueling coupling”
8. Auxiliaries “pressure transmitter, temperature transmitter, pressure safety valves, manual
ventilation valves check valves, excess flow valves ”
2.2.1.6 Flow calculations “operation”
There are many types of flow meter’s company, we are dealing with 2 main companies flow safe “micro
motion” and Enders Houser “proline”, also there are many flow calculations’ method such as
electromagnetic, coriolis, ultrasonic, vortex, thermal and differential pressure. Each of this method is used
according to the application field even they could be used for most of it
From the basic ideas that if we are going to measure the flow of a certain gas that we need a mass flow
meter. And due to the coriolis high accuracy we always use coriolis method
Coriolis method
Coriolis force occurs when a moving mass is subjected to an oscillation perpendicular to the direction of the
flow. The measuring system actually determines and evaluates the resulting effect on the measuring tubes.
The system will measure several parameters simultaneously: mass, volume, temperature, density and
viscosity
The flow meter consists of two main parts the flow meter and its transmitter, the flow meters measure the
flow and send the data to the transmitter that send it as a signal with frequency to the Model 33 that
calculate the price and display it on the LCD
2.2.1.7 Car Charging process: “operation”
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Once the charging coupling plugged in the car and pushes the micro switch. The micro switch
sends a signal to the PC “model 33” to reset the counters at mean while the fill minder gives a
signal to open the control valve for one second. To indicate
The car’s cylinder pressure
The ambient temperature
The fourth stage’s temperature after the cooling process
According to that it decide the following
From which bank the charging will start
The target pressure at which the charging process ends “target vehicle
pressure”
The dispenser start to charge the car until the car’s cylinder pressure reaches the bank pressure at this
while the fill minder gives a signal to close the low pressure actuator and opens the medium bank then the
third.
In case that the pressure of the cylinder didn’t reach the targeted pressure the PLC gives a signal to close
the banks actuators and open the direct fill valve. And when the cylinder reaches a targeted pressure the
fill minder gives the signal to the control valve to end the charging process by closing the control valve
2.2.2 Safe compressor operation
2.2.2.1 Compressor
The gas entre the compressor through a flange then to an entrance pipe to a manual ball valve, which have
to states either fully opened or fully closed. This valve is used to close the gas’s path in case of maintenance
operation on the compressor.
After that the gas pass through a gas filter for filtration of the gas from impurities, there is a differential
pressure gauge on this filter which measure the gas’s pressure after and before the filtration, in case that
the filter works perfectly the pressure after and before the filter will be the same but in case of the filter
has a problem there will be a difference in pressure.
The filter’s gauge has ranges first the black region at which the filter is working well, and there is the red
region at which the filter should be replaced. This filter should be daily drained from any impurities or
condensates inside it. Inside the filter there is a level switch that in case of the condensate’s level increase
it sends a signal to the PLC to shut the unit of until they drain the filter.
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After the filter the gas pass through a check valve to prevent the gas from retuning to the network,
afterward the gas goes through pressure damper to absorb any oscillation in the gas’s pressure, so the gas
exit the pressure damper with constant flow rate.
When the gas exit the pressure damper it face the inlet shut off valve which is a pneumatic valve that is
controlled through the PLC, this valve opens and closes automatically when the compressor starts and
stops.
Then the gas passes on a pressure transmitter “PT” to measure the entrance pressure, this pressure
transmitter measure the pressure mechanically and translate it into an analog electrical signal. Then the
gas goes to a pressure safety valve “pressure relive valve, P.S.V” that escape the excess pressure in case its’
increase than a certain limit, Example The P.S.V for the inlet gas’s pressure is from 26-30 bar there will be a
P.S.V withstands 40 bar afterward the gas entre the first stage.
After the compression the gas gain temperature due to the heat compression effect, that is why the gas
exits the stage to a cooler to compensate its temperature “which will be explained later” after the cooler
the gas passes on a temperature transmitter “TT” to send it to the PLC then the gas passes on P.S.V then in
entre an inter stage scrubber to filtration of the gas from condensates and impurities that result due to the
compression process, then the gas goes to the next stage.
How to drain the condensate?
1. Insure that the two valves that are on the drain line are tightly closed
2. Open the ball valve slowly
3. Open the needle valve slowly “rotate the black hand slowly” until you hear the sound of the
condensate, you leave it until you hear the sound of gas exit.
4. Close the ball valve first then close the needle valve
Hint
It doesn’t mean that if you opened the needle valve that the condensate will exit the filter in a higher flow
rate because in that case the gas will exit leaving the condensate inside
2.2.2.2 Lubrication cycle
Lubrication cycle components:
1. 2 oils pumps that are operated by electrical motors
2. Oil-water heat exchanger
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3. Lubrication oil press manual adjust
4. Maintaining oil press manual adjust
The lubrication circle has to main parts inside safes’ compressors, they are Lubrication circle and
maintaining circle, those circuit are driven by 2 pumps coupled with an electrical motor’s shaft
The lubricating circle is responsible for the lubrication of the main moving parts in the compressor,
maintaining circle is responsible for the pressure on the piston to keep it stick with the cam; each of those
circuits has an oil pressure regulator.
2.2.2.2.1 Lubrication circuit
The electrical motor works on rotation of the oil pump that work to push the oil to the pressure transmitter
PT that transmit the oil pressure to the PLC, that will stop the compressor in case of the pressure of the
lubrication falls beneath a certain level, afterward the oil goes to a water cooler that cool the oil’s
temperature down before it entre the compressor in order to cool and lubricate its parts. Then it exits the
compressor on a regulator. Then it meet the oil that exit the maintaining circuit and together return to the
oil pan to lubricate the crank shaft after that to a filter has an indicator that indicate its state of filter then
to an oil tank. In case of that filter is stuck there is another path with check valve on it to ban the reverse of
the flow.
2.2.2.2.2 Maintaining circuit
The electrical motor works on rotation of the oil pump that work to push the oil to the pressure transmitter
PT that transmit the oil pressure to the PLC, that will stop the compressor in case of the pressure falls
beneath a certain level, then it goes to a filter to filtration process. Then the oil enters all the stages to push
the piston to keep it stick with cam then it exit to entre oil regulator afterward it meet the oil from the
lubricating circle.
We plug the nest component on the oil tank.
1. Temperature transmitter to transmit the oil temperature to the PLC top shut the unit down in case
of the temperature increase than a certain limit
2. Pressure transmitter to transmit the oil pressure that result due to the increase in the oil level
2.2.2.3 Cooling circuit
Components of cooling circuit
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1. Gas water heat exchanger
2. Water air heat exchanger
3. Water pump
4. Water compensation tank
5. Manual control flow valve
6. Manual control pressure valve
7. Chiller “New SW series”
After each stage there is a gas water heat exchanger that transmit the heat to the water which by the aid of
the water pump is pushed through the pipes to the water air cooler then the water return after it maintain
a cold temperature. We must adjust the right water’s cycling speed to avoid the boiling of the water.
Hint
Mainly there are two types of coolers Tube-Tube and shell-tube, generally the gas flow is opposite to the
water flow.
The yellow arrows indicate the gas flow and the green arrows indicates the water flow
In new systems
After the normal circuit of the water cooling system inside the compressor, the fourth stages is consisting
of two main stages first classical cooling by heat exchanger and chiller stage which is a unit that force the
temperature of the water into a very low ranges in order to maintain low output gas temperature. This
cooling system make a temperature differences in the output gas about 10 °C. Also the density of the
flowing gas will be larger as the density increases when the temperature decreases. That leads to increase
in the mass flow, In addition to the cold gas will decrease the use of spare parts like the o-rings of the
coupling instrument.
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Event:
Once there was an error appears on the screen of the chiller FL that indicate that there is no flow, first we
checked the tank and it was filled with water but we didn’t notice that there are two valves one to make
sure that there is water in the tank and the other was to open the flow to the pump
2.2.2.4 Car charging process: “operation”
Once you take the filling unit from its place in the dispenser. You will notice that the red light is flashing and
then *
Mechanical review:
1. Changing the rotational motion into reciprocating motion
1.1 Crank shaft method:
This is the system is equivalent to the SW mechanism, but this is simple diagram for the system,
every piston is shifted with a certain angle from the other
This is the general method of the crank shaft method
1.2 Cam method:
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There are two main ways of cams one uses a circle but with fixation not from its axis, and the other
is using an elliptical shape, this technique is usually used in the safe’s ST series, that is why there is
a maintain circuit in those kind of compressor
2. Single acting and double acting method
2.1 Single acting compression
In this method of the single acting compression the piston compress in a stroke and return without
doing any work. That makes the piston find a resistance while going in the outlet stroke while zero
resistance while inlet stroke there is no resistance. So this method you need to equate the pressure
over and under the piston to avoid hammering effect while inlet stroke so you need a kind of bypass, in
order to make what they call pressure pillow
You could find this bypass in SW200F6-EM-110 machine obvious when you stand in front of it also it exist
Gemini compressor to. But its function becomes useless in presence of double acting method of
compression.
2.2 Double acting compression method
In this method the piston compress at both ways inlet and outlet because while inlet stroke at a certain
side there is a compression stroke on the other side. So there is no place to pillow method.
Bypass
P in P out
P in
Sealing
Piston
In
Out
Clearance pocket In
In
Out
Inlet Valves
Outlet Valves
Stroke
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The curvature on the beam indicates the in and outlet valves. Since the curvature on upper side indicates
the inlet and the lower side indicates the outlet.
What is the clearance pocket?
The clearances pocket is a method to control the flow rate of the machine through controlling the volume
of the first stage. Since in case the first stage’s volume increases that results not all the gas which has been
compressed to go out of the room, so a residual pressurized gas remains in the room that lead to a delay in
opening the inlet of the gas in the room since it will need an extra displacement to lower the pressure. So
it takes longer time hence the output flow rate decreases. And vise versa
3. Bearing
There are two main types of bearing friction and Antifriction bearing
3.1 Friction
1. Ball bearing
2. Needle bearing
3. Thrust Bearing. Picture needed*
There are many types of bearing you could find more SKF catalog; it is used in high speed applications, and
normal and medium loads.
Lubrication method:
1. Greasing through “Injection Method” is method used for open types of bearing.
2. Self lubricated is a method that used for closed type.
You could identify that the bearing is open or closed type through the code that is written on the ball,
where 2Z stand for closed type bearings, while C3 is used for open type.
Usage: this type of bearing is usually used in small and medium size machinery as single stage centrifugal
pumps, air compressor, P.D pumps, and Turbo chargers.
3.2 Antifriction
Out
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1. Sleeve friction
This type is used for high speed applications with high loads
Lubrication method:
1. Oil film lubrication
2. Hydro dynamic lubrication
3. Hydro static
Usage: Anti friction bearing is usually used in large machinery like steam turbines, gas turbines, hydraulic
turbines, Multi-stages machines.
How to read the number of the bearing?
i.e. 6322, to calculate the bore diameter from this number take the last to numbers “22” and multiply them
by 5
Event:
Be careful with the material selection of those types of bearing. Since there was a certain package that we
import that made from a very bad material that when we use it two days and they broke down. Because
they can’t stand the heat formed inside the compressor
4. Gears:
Gears are used as a power transmission element as in automotive gearbox or as reduction gear elements as
in drivers.
There are many types of gears:
1. Spur gear
2. Bevel gears
3. Helical spur gears
4. Helical bevel gear
5. Worm gear
When you form a system of gears they are called train of gears those kind are
1. Simple gear train
2. Planetary gear train, this type is used in hydraulic power, power transmission
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5. Pumps
There are two main types of pumps. There are PD “Positive displacement” pumps and Dynamic pumps.
5.1 PD pumps
Displacement action pumps produce high pressure and low flow rate. And its main types are reciprocating
(plunger and pistons) and rotary (vane-screw-lobe-gears)
5.2 Dynamic pumps
Dynamic action produces high flow rate and low pressure. And it is used for multistage for high pressure. Its
types are axial, radial, mixed.
6. Engines
There are two types of mechanical engines internal and external compassion engines.
6.1 Internal compassion engines
a. Spark internal compassion engine “SIE”
It depend on a spark to ignite the mixer, it has many types according to the strokes. There are many
types but mainly they are cylindrical or rotary engines.
b. Compression internal compassion engine “CIE”
It depend on the temperature to ignite the mixer, mainly it depend on organic oils in working.
6.2 External compassion engines
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Mainly they are used in GT turbines “gas turbine” but it is a very low efficiency engines, and it
depends on the exhaust in order to take the work.
7. Alignment of Drivers axis
There are two main parameters in the alignment first the radial alignment and the angular alignment.
7.1 Radial alignment
It is the radial parallel shift of the main axis
7.2 Angular alignment
It is the deviation of the axis with an angle with the main axis
When we measure the alignment in the periodical maintenance we have a device with two gauges one of
them indicate the radial deviation and the other indicate the angular. The maximum allowed reading for
the gauges is 5 and zero is the best.
What is the end play?
It is an axial clearance in the crank shaft driver or the driven in
order to give free space for the coupling to move axially. And the
readings should be in the range of 0-5 saaw
8. Types Coupling
There are two types of coupling flexible and rigid coupling
8.1 Flexible coupling
It is a kind of coupling where the driver and the driven are connected together through rubber
connection or shims, and those type of coupling are used in our compressors
Shims: are metal slices with high elasticity
Axial
Angular
Driver Driven
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8.2 Rigid coupling
It is a kind of coupling that the driver and the driven are connected tightly together through a 2
flanges and a sets of bolts, this kind of coupling is used for the small machines
8.3 Chiller
Chiller is a device is used to decrease the temperature of the outlet gas, which means the increase
of the density of the out put gas. Also there is another advantage from using the chiller which is
that the O-rings of the coupling will last longer.
8.4 Friction joint
The friction joint is a mechanism which fix
any flange with the crank shaft. It consist
of two parts when you tight the bulks a
part of it goes down in order to hold the
crank shaft and the other part hold in the
flange.
2.3 Piping and Instrumentation
2.3.1 Piping and fittings
This next part is mainly about parker fittings and was written according to their metaphors and
perspective of fitting categorization
Driver Driven
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2.3.1.1 Tube fittings (CPI & A-LOK):
There are two main standards for fittings; the first standard is the American standard that mainly
depends on the ferruling on the tubes by one cycle and half, and the European standards that
depend on the flaring of the tubes.
Also there are two types of threads there are NPT “national piping taper” and BSP “British standard
piping”.
NPT: is 55 thread’s angle. Pitch measured in inches, truncation of the root and crest are flat, taper
angle 1°47’
BSP: 55° thread angle. Pitch measured in inches. Truncation of root and crest are flat. Diameter
measured in inches.
Hint:
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Always we use ferruling with WF and JW while safe’s systems use the flaring method
There are many categories for fittings
Always U.S.A use the inches in measurement while the international standards is the metric
standard
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When you are ordering a tube fitting the metaphors for the fitting is actually indicate the
specification of the fitting
Example: The part number shown below is the parker A-LOK stainless steel male connector for 1/2’’
O.D. tube (-8) and 1/4’’ male pipe thread.
How to order CPI Inch Parts:
CPI/A-LOK
fittings
Tube to male fittings
Tube to Female Fittings
Tube to Tube fittings
Port Connectors
37° Flare (AN)to
CPI/A-LOK
Tube to O-Ring seal
Tube to welded system
Analyticacl fittings
Bared Fittings
Components
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How to order CPI inch parts
How to order A-LOK inch parts
Parker CPI/A-LOK tube fitting re ordered by part number as listed in this catalog
Size: Tube and pipe thread sizes are designed by the number of sixteenth of an inch (1/2’’ tube =
8/16’’=8). (1/4’’ pipe thread = 4/16’’ = 4).
Straights & elbows: call out largest CPI/A-LOK tube end size first followed by the smaller CPI/A-LOK
tube end or pipe thread size
Tees and cross: For drop size tees-first size the run (1 to 2) and then branch (3).Example- the size
designator for male run tee for 3/8’’ O.D. tube and 1/4’’ male pipe thread would be 6-4-6. For
crosses – first size the run (1 to 2) and then the branch (3 to 4). For tees with all ends the same, use
the tube and size before and after the style designator; i.e. 4-4-4 JBZ (CPI), 4ET4
Material: Basic material type (B = Brass, SS or 316 = stainless steel, type 316; S=steel; A= aluminum;
M = Monel; HC = Hastelloy C-276 ; IN = Alloy 600; SS20 = carpenter 20 ;T= titanium)
How to order metric parts:
How to order CPI metric parts
8
1st End 1/2'' tube
O.D
4
2nd End 1/4'' Pipe
Thread
FBZ
Fitting Type male
connector
SS
Material stainless
steel
8
1st End 1/2''
tube O.D
MSC
2nd End 1/4'' Pipe
Thread
4
2nd End 1/4'' Pipe
Thread
N
Thread Type NPT
316
Material stainless
steel
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How to order A-LOK Metric parts
Parker CPI/A-LOK tube fitting are ordered by part number as listed in this catalog.
Size: Metric Tube is designed in millimeters and prefixed “M” (i.e. 12 mm tube= M12) the pipe
thread size is written as a fraction (i.e. 1/4 NPT = 1/4N).
Tees & crosses: for drop size tees – first size the run (1 to 2) and then branch (3). Example – the size
designator for male run tee for 6 mm tube and 1/4’’ male pipe thread would be 6-4-6. For crosses –
first size the run (1 to 2) and then the branch (3 to 4). For tees with all ends the same size, use the
tube end size after the style designator; i.e., JBZ 4-4-4 (CPI), ETM4 (A-LOK).
Material: Basic material type (B = Brass, SS or 316 = stainless steel, type 316; S=steel; A= aluminum;
M = Monel; HC = Hastelloy C-276 ; IN = Alloy 600; SS20 = carpenter 20 ;T= titanium)
Thread types:
N= NPT
K=BSP taper
R or BR=BSPP
M=metric
R-ED= BSPP
Assembly and remark Instructions:
1. Parker instruction tube fittings are completely assembled and ready for immediate use. Simply
insert the tube as illustrated until it bottoms in fitting body. (If the fitting is disassembled, note that
the small tapered end of the ferrule go into the fitting body.)
GBZ
Style female
connector
12
Tube O.D 12mm
1/4
Thread Size 1/4''
K
BSP
SS
Material stainless
steal
M12
Tube O.D 12mm
FSC
Style Female
Connector
1/4
Thread Size 1/4''
N
Thread type NPT
316
Material stainless
steal
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2. Tighten nut finger tight. Then tighten nut with wrench an additional 1- ¼ turns. Hold fitting body
with a second wrench to prevent body from turning. It is helpful to mark the nut to facilitate
counting the number of turns. But for the tubes less than 3/16’’ or less than 4mm use ¾ turn.
Usually we chose the fitting according to the working pressure and the temperature.
2.3.1.2 Instrument Pipe & ISO Conversion Fittings
Those kind of fittings are originally manufactured with Brass and stainless steal for special order you should
contact the company
1. Instrument and Pipe fitting:
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Pipe Fitting
Male Hex Long
Nipple Male Close Nipple
Adapter
Male Hex Nipple
Female hex
Coupling
Reducing Bushing
Male Elbow
Femal Elbow
Female Elbow
45° Street Elbow
Female Tee
Street Tee
Male Branch
Tee
Male Tee
Female Cross tee
Pipe Cap
Hex Head Plug
Hollow Hex Plug
Straight Thread Adapter
Hex Head Plug
Hollow Hex Plug
Straight Thread
Reducer
Male straight head to
female NPT thread
Connector to SAE straight
thread
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NPT threads:
The National Pipe Taper NPT thread has a thread flank angle 60 inclusive and is mainly used in the
petrochemical and process industries.
NPT – National Pipe Taper Thread for connections where pressure-tight joints are made on the thread
utilizing a thread sealant.
How to order
Size: pipe thread sizes are designed by the number of sixteenth of an inch
Thread Type: All pipes thread are national pipe taper NPT unless other wise designated.
Tees and Crosses: For tees that are the same on all ends the size designation is as follows:
6-6-6 FT-B would be a 3/8’’ NPT female tee in brass, a ¼’’ NPT Female cross in 316 would be a 4 FX-SS.
2.3.1.3 Cylinder connections
6
1st End 3/4'' NPT Male Pipe
4
2nd End 1/4'' NPT
Pipe Thread
MHN
Fitting type Male Hex
Nipple
SS
Material 316 SS
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2.3.1.4 Partek PFA/PTFE Products:
Parker Hannifin’s Partek operation facilities manufacture flow control products for use in fluid systems
where corrosion protection is required or where media purity must be safeguarded.
The wetted surfaces of the entire product are chemically inert, made of PFA or PTFE
External material are made of polyethylene (HDPE), polyvinylchloride (PVC), polyvinylidenefluride (PVDF),
perfluoroalkoxy (PFA), ABS plastic knobs are used in some
There are many ways of connecting those kinds of tubes:
cylinder connections
CGA Inlet connection
components
CGA Outlet Adapters, Blank caps
& Plugs
Cylinder Value
Outlet and caps
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Fluor polymer tubing products:
Chemical properties
Resistivity to corrosive agent
Non-solubility
Long term weather ability
Non-adhesiveness
Nonflammability
Electrical properties
Low dielectrical constant
Low dissipation factor
High arc resistance
high surface resistance
High volume resistivity
Mechanical properties
Flexibility at low temperature
Low coefficient of friction
Stability at high temperature
Fluid handling tubing and pipe
High purity tubing
Retractable coils and formed shapes
Fractional industrial and heavy wall tubing
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Striped tubing
Welding and standard rod
Tubing for air and water sampling
Schedule 40 and 80 pipe
Metric sizes
Electrical insulation tubing
Spiral cut cable warp
Convoluted tubing
Heat shrink Tubing
2.3.2 Ball valves
These are the main categorization
of the ball valves.
2.3.2.1 B series Ball values
First those kind of valves could easily used manually , pneumatically and electrically actuated two-way B
ball series ball valves provide quick ¼ turn on off control of fluids utilized in process and instrumentation
application. A broad selection of valve body, seats, seal material provides a wide range of pressure and
temperatures at which the valves may be used.
B series
MB series
HB series
SWB series
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2.3.2.1.1 Two ways B series Ball Valves
Item # Part Description
*1 Connector O-ring
*2A Seat Retainer
*2B Seat
*3 Retainer seat
*4 Ball
*5 Body
*6A Stem
*6B Stem seal
*6C Stem washer
7 Packing nut
8 Handle
9 Handle set screw
10 Panel nut
*11 End connector
These kind of ball valves series are manufactured from many types like 316 stainless steal that could stand
up to 6000 PSI (416 bar) which they call B8 series
The sign * means that it is a wetted part
2.3.2.1.2 Three way B series ball valves
Those kind of valves could easily used manually, pneumatically and electrically actuated three way B series
valves may be used as diverting or selecting valves for fluids utilized in the instrumentation process.
There are two schemes of operation for this valves either the inlet port is the one in the bottom that will
give it a higher pressure limit (6000 PSI) or from a side port and it will give it a lower working pressure
(3000 PSI).
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A. Diverting Valves:
You could identify this valve by the absence of the Diverter Valve.
Item # Part Description
*1 Connector O-ring
*2A Seat Retainer
*2B Seat
*3 Retainer seat
*4 Ball
*5 Body
*6A Stem
*6B Stem seal
*6C Stem washer
7 Packing nut
8 Handle
9 Handle set screw
10 Panel nut
*11 End connector
B. Selector Valves
You could identify this valve by the
Item # Part Description
*1 Connector O-ring
*2 Seat
*3 Sear retainer
*4 Spring
*5 Seat retainer washer
*6 Back-up ring
*7 Connector O-ring
*8 Stem retainer O ring
*9A Stem
*9B Stem washer
*9C Stem washer
10 Packing nut
11 Panel nut
12 Handle
13 Ball
14 End connector
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How to order
1. Two way Valves:
4Z 4F – B6L J – BP
Describe a B6L ball valve with a ¼ ‘’ CPI end connection for port 1 and a ¼ ‘’ female NPT end
connection for port 2, PTEF seats, PTFE stem and body seals, Brass construction, with a
panel mounting nut.
8A * - B8L J – BN – SSP
Describe a B8L ball valve with a ½’’ A-LOK end connection for ports 1 and 2, PTFE seats,
Buna-N rubber stem and body seals, stainless steel construction, with a panel mounting
nut.
M3A * - B2L J2 – VLT – SSP
Describe a B2L ball valves with 3 mm A-LOK end connections for ports 1 and 2, PCTFE seats,
fluorocarbon rubber body
Hints & key
a. When we are talking about the size of the fittings under the American standard so the 4
indicate 4 of 16, in case of metric standard you will find a capital Letter M before the number
that indicates the size in mm.
b. Z means CPI fittings while A means A-LOK
c. * means that the input port is similar to the output port.
d. B6 and B8 is the series of the ball
e. J means PTFE “Polytetrafluoroethylene” while J2 means PCTFE “Polychlorotrifluroethylene”
f. SS means stainless steal while B means Brass,
g. P means panel mounting nut
2. Three way diverter valves:
4Z-4Z-4F – B6X J2 – V - BP
Describes a B6L ball valve with ¼ ‘’ CPI end connection for side ports a 1 and 2, ¼ ‘’ female
NPT end connection for bottom port 3,PCTFE seats ,fluoro rubber stem and body seals,
brass construction and mounting nut.
2Z -B2X J2 - SSP
Describe a B2L ball valve with 1/8 ‘’ CPI end connection for ports 1, 2 and 3 PTFE seats,
PTFE stem and body seals, stainless steel construction and panel mounting nut. Note: if 1,
2, and 3 are the same eliminate the port 2 and port 3 designators.
3. Three way selector valves:
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4M 4M 4F – B6X S2 – EPR – SSP
S means spring and they write it instead of the J
There are many types of actuator that can fit with the B series ball valves
a. Manual valves: which have round, Lock-out Devices.
b. Actuation Options:
a. Double acting: it has two main signals, one of them to open it and the other to close it.
b. Spring return: the spring make the restoring torque
c. Electrical actuator: it is actuated by an electrical signal
Note:
When ordering actuated B series ball valves. O-ring stem seals or live-loaded stem seals are recommended
to minimize the need for stem seal maintenance.
Also if we noticed the difference between the two 3 ways valves “diverter and selectors”, we will find that
we should use selector “the one with the springs” since we have the high pressure comes from a side port
not from the bottom one.
2.3.2.2 MB series Ball Valves
Parker MB series ball valves with their rugged compact design, offer positives shut off or directional control
of fluids in process ,power and instrumentation applications. The unique one pieces seat/packing design
insures excellent sealing characteristics while accommodating a superior temperature range and cycle life.
These valves working pressure is up to 3000 PSI (207 bar).
**** Picture
2.3.2.3 HB series ball valves
Parker high pressure HB4 series ball valves, featuring super case ball and trunnions, provide reliable shut-
off or switching function. The super case trunnions style ball enhances the resistance of the trunnions
against seizure and the resistance of the spherical ball to particles abrasion. The compact and rugged
design employs spring-loaded seals for high cycle life and low operating torques at pressures up to 10000
PSI (689 bar).
These valves working pressure is up to 10000 PSI with PEEK seats.
****pictures++++materials
Available end connections:
Z- One ferrule CPI, A- two ferrules A-LOK compression and F- ANSI/ASME B1.20.1 internal pipes thread
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2.3.2.4 Swing-out Ball valves
Parker’s three-piece SWB ball valves are durable valves that can handle the pressure and piping loads. The
centre section can swing out to the quickly and easily replace seats, seals and the ball without major
disruption to the piping system
***picture needed
2.3.3 2.3.2 Dispensers
These systems have been designed for the purpose of filling motors vehicles, which based on mass flow
meters that work on coriolis forces; such technique has many advantages on the traditional way which
determines the quantity of fuel by using approximate calculations.
The following are some of the advantages
Precision of the measurement (±1%). The mass of delivered gas is determined through direct
measurement, and this is an independent parameter not affected by pressure or temperature’s
condition.
Also the dispenser is equipped with a system that fills a tank respecting gives limits of the pressure
and temperature respecting a maximum pressure inside the vehicles tank.
The principle of measurement is based on the controlled generation of coriolis forces, existing on a system
which simultaneously presents a sire motion and a rotating motion.
The mass flow metering unit basically consists of a casing containing two aligned measuring tubes, trigger
and optic sensor; these measuring tubes vibrate in counter phase in a diapason like manner. The coriolis
forces acting on the measuring tubes create changes in the position of the oscillation phase of the tube.
During the transit of the natural gas mass, the oscillation is retarded at the inlet side and accelerated at the
outlet side. So the larger mass flow the greater is the difference of phases, at zero flow both of them are
identical.
2.3.3.1 Safe’s MOD.ESP 22/3
Those kinds of dispensers are self sequencing at mean while they are self controlled. Their operation is as
follows.
The gas sent directly from the compressor or from the storage system reaches the dispenser from the low,
medium and high pressure inlets lines.
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Here the gas is filtered by the filters and intercepted by the driven valves operated by the solenoid
valves(7*), hence envoy to the meters(1), which not only meters the mass but also controls any excessive
flow of the gas via a built in electronics detector
For the safety motives of the two hoses there are break away then there are the flexible hoses, then the
three way valve.
CPU’s sequence of operation as follows, the CPU head performs a initialization cycle and if all the internal
check is negative, it activate the driven calve (6)and start to refuel from the low pressure, during this phase
the various displays are tested when all the sections are lit up one after another.
The gas start to flow through the metering unit that sends 100 pulses every Kilogram of the gas dispensed.
The head switch from an actuator to another when the flow goes bellow a certain value, but this switch
doesn’t happen immediately after the decrease in the flow but it takes a few delay seconds.
Postponed topics:
PLC types and Soft wares
Inverters and Soft starters’ circuits
Flow meters types and theory of operations
Dispensers and its cards
Sequential panels and pneumatic valves and its types
Fault log
Mechanics:
Unlades