ACTUATOR TYPE and FEATUREFor Valves

Oil & Gas

Shipbuilding

Refinery &Petrochemical

Power Plant

S&T International Co.

Stanley ParkPresident, P.E.Mobile : +82(0)10-3840-0721 Tel/ Fax: +82(0)2-400-8039 E-mail : stanley.park@daum.net

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- CONTENT -

● PNEUMATIC ACTUATOR

● ELECTRIC MOTOR ACTUATOR

● HYDRAULIC CYLINDER ACTUATOR

● ELECTRO-HYDRAULIC ACTUATOR

● HYDRAULIC CYLINDER with Counter Weight

▶ The article is summarized not only for my presentation taken at World Famous Oil/Gas majors and Korea leading EPCs’ engineers but

also based upon the experience through numerous projects when I worked as SEVERN GLOCON Korea regional manager, and so it

may be helpful for engineers engaged in the plant.

August 2016

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PISTON TYPE DIAPHRAGM TYPE

ADVANTAGE

1. Produces 30 (2.1kg) - 7,500pound (3,400kg) force with a maximum pressure rating of 150psi (10bar) 1. Maximum force rating is 4.1 bar. Actuator with the same area as piston type is 1/3 force

2. It is possible to open / close valve quickly. (Booster and solenoid valve can be applied for up to1 sec) Some of the new products have Servo Motor installed for less than 1 second: CCI Quick-Trak) 2. Essential fail-safe operation is possible

3. No risk of explosion or ignition due to use of air or low air pressure, and satisfies machine safety requirements

4. Low cost and light weight compared to other Actuator

5. Simple control, good reliability and easy maintenance

6. Accuracy is less than 0.01 inch and repeatability is less than 0.001 inch 6. Compared to Piston type, diaphragm area is wide and air pressure is relatively low, so controlprecision is good

7. Cylinder length is long so long stroke is possible. For the same thrust force, its volume is about1/3 of that of diaphragm. 7. Easy to adjust in the field

8. Compressible air makes it possible to store pressure energy such as Air Volume Tank 8. Actuator, the longest familiar to factory technicians

9. Reversible mounting and use when needed in the field. 9. N/A

DISADVANTAGE

1. Compressor and air supply limitation has low and low speeds, and compressors must maintain a constant operating pressure

2. Positioner is certainly required for Actuator operation 2. Control at high ambient temperature is difficult

3. There is O-ring in the piston and friction occurs, so the degree of control is lower than Diaphragm 3. Stroke length is limited and stroke length of 90mm or more is not available.

4. Due to the durability of compressible pneumatic equipment, it is not possible to obtain a large force of more than 10 bar 4. Due to the material of diaphragm, air pressure of 4.1 bar or above can not be used

5. Precise control is difficult due to influence of operation speed when changing power load 5. The Net Thrust is limited to a maximum force of 3,000 pounds (1,360 kg) due to the reaction of thespring force

6. Piston O-ring is made of Viton or other materials and should be periodically replaced due to abrasion raised by friction

6. Diaphragm material is a rubber series (Neoprene), which tends to be torn by carbonization whenused for a long time

◙ PNEUMATIC ACTUATOR

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COMPONENT SHAPE● Actuator

Spring Diaphragm: Single Acting

Piston Type- Single Acting with Spring Return: Return to original position at Air Failure

- Double Acting without Spring: Since air is supplied to both ends of cylinder, it remains in its position at the time of airfailure or changes its position due to fluid force flowing through the valve

- Double Acting with Spring: Add spring when air pressure alone is not sufficient (example: Anti-surge Valve for Quick Closing)

● PositionerHart Protocol: a. Fisher is used in the past as a communication method and widely used worldwide

b. Digital data is transferred through 4 - 20mA analog signal c. Bidirectional communication is possible, and data is exchanged through DCS and I / O module

Foundation Field-bus:The role of DCS can be distributed to each Local Equipment or Local Control Panel. It is possible to communicate witheach equipment, exchange data, and even input all specification and data sheet to Positioner and control accordingly

Profibus: It is used mainly in Europe and Africa in the same way as the foundation field-bus.

● Position TransmitterThe potentiometer indicates the opening of the valve and sends the resistance value to the DCS so that it can be seen step by step from 0% to 100%

● Limit Switch

Since the contact is only high / low, setting can be done with the set value. Mainly used as an on-off function

● Air Set(Air Filter + Pressure Regulator + Pressure gage) :- Use air of 1.2 to 5.0 kg/cm 2

- Moisture and dust are removed from the first chamber and decompressed from the second chamber

- In case of cylinder type, Oiler is attached and mixed with air to supply

● Volume Booster

Applied to supply a large amount of air to the actuator at one time, and the diaphragm valve in the booster is controlledfrom the positioner by the air pressure signal

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COMPONENT SHAPE

● Lock-up Valve

In case of Air Failure, it acts as a lock to prevent it from escaping when it goes below setting pressure in order to prevent air from actuator from being released. When there is a deviation from preset pressure, Locking function. After the valve is stopped in thefinal signal state, the air line is restored and the valve is normally operated

● Solenoid Valve

When power is supplied to the solenoid valve, air flows to the actuator, and when the power is turned off, the air of the actuator isvented. Use 1-Way or 4-Way valve if it is mainly used for emergency shut off of control valve. The 2-Way is used as an electricalsignal to block air signals, and the 3-Way is used for emergency shutdown or emergency opening of a diaphragm actuator or singleacting actuator. 4-Way is used for Dual Acting.

● Air Compressor

External air is compressed and supplied to the control valve. In case of the control valve, the compressor is operated by setting the maximum value to 10 bar

Reciprocating Type

- Vibration is relatively large because the piston reciprocates using the crankshaft

- Valve, Linkage, etc. There are many joint drive parts and rotation is slow, so low frequency noise is generated.

- Belt adjustment, floor foundation, etc. are required.

Screw Type

- Two female and male screw rotations compress space volume axially

- High-speed rotation is possible and no low-frequency noise

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◙ ELECTRIC ACTUATOR

FEATURE APPLICATION

ADVANTAGE ● Applies to almost all valves

1.Applicable to all kinds of valves with reliable operation at relatively economical prices ● Suitable for large size and high pressure MOV

2. On/off of valve control, Fast Open/Close, Proportional control, Time control, Remote control, etc. is available so itcan be used as a valve driving device. - Butterfly, Gate, Ball, Globe, Check

3. Stiffness is best among Actuator Type because it operates directly by receiving signal from controller ● Applies to almost all valves

4. Even if it is far away, it can be installed simply by wiring (no media like Pneumatic Air or Hydraulic Oil is required)

5. Compact design allows high thrust output

6. Noise is lower than other actuators.

7. The accuracy range is +/- 0.000315 inch and the repeatability is best at less than 0.0000394 inch

DISADVANTAGE

1. Operation speed is slower than Pneumatic and it is expensive (about 4 ~ 5 times: including positioner, solenoid, airset, booster etc.)

2. Gear boxes and electrical wiring are complex.

3. Explosion-proof type shall be used in explosive area and it is less safe than air type in case of fire

4. Modulating operation is limited due to motor operation.

5. Compared to pneumatic, there are moving parts, which makes maintenance cost much.

6. Does not cause environmental pollution because there is no fluid leakage

7. The actuator can be networked and reprogrammed, providing instant feedback on diagnosis and maintenance

8. Motor overheats and wear occurs during continuous operation.

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◙ HYDRAULIC ACTUATORFEATURE APPLICATION

ADVANTAGE ● API10000 - API15000 Valve

1. Because oil pressure is applied to the piston, a linear thrust of 14,000 pounds (6.4 tons) is generated when 2,000 psi is applied to one side of the 3 "piston. The force produces about 25-30 times of the pneumatic force, min. 1,750 pounds (770kg) to max. 265,000 pounds (120 tons) is available.

● Large size & High Pressure Valve requiring TSO

2. Air is a compressible fluid, but oil is incompressible and there is no volume fluctuation, so High Stiffness and Resolution are excellent. ● Turbine Bypass Valve 3. Fine control is possible, and the response speed of pressure is 1000m / s, which is faster than the air pressure of 50-70m / s, so the speed can be controlled

easily.4. Small vibration and smooth operation.

5. Lubricating oil is not necessary because the operating oil itself acts as lubricant.

DISADVANTAGE1. The maximum possible speed is very slow at 100 mm/s.

2. Viscosity change of oil increases quickly by temperature change.

3. Periodic replacement is necessary due to the oil clogging (pollution).

4. There is no separate energy storage vessel like air volume tank compared to pneumatic

5. Thick-wall tubing for high oil pressure, gas bubble purging, and leak-free distribution network shall be configured

6. Price is high, time is relatively long, high skill is required, so maintenance is not easy.

● Actuator ● Hydraulic Power(Supply) Unit ● Hydraulic Actuation Diagram

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COMPONENT SHAPE

● Actuator : Single Acting and Double Acting

● Hydraulic Pump : Gear, Vane, Piston type is the basic power for operating hydraulic motor or cylinder.

● Control Valve : Spool Type Directional Control, Spring Loaded Pressure Control

● Oil Reservoir : Maintain necessary flow rate, keep oil temperature properly, prevent bubble generation

● Accumulator : Attenuation of the pulsation of the fluid and pressure compensation. Compensate for oil volume change due to temperature change.Spring Load, Piston, Bladder Type

● Oil Cooler : Oil is kept at 40-60 ° C to prevent sludge generation and deterioration due to temperature rise of oil and destruction of oil film.

● Silencer : Keep noise below 85dBA

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◙ ELECTRO-HYDRAULIC ACTUATOR ADVANTAGE APPLICATION

1. Simplicity of electric operation and hydraulic control gives high precision and mechanical reliability ● Applicable to all kinds of valves

2. Safety shutdown and precise modulating control are possible (High Stiffness)3. Non-intrusive Intrinsically Safe Bluetooth settings / couplings, Actuator configuration and data logging files can be transferred from the field to a standard PC

for analysis / storage4. Stroke Speed can be less than 1 second.

5. Smart control is possible by bus communication through major protocol

6. Small, compact and easy to handle / operate. Oil Leakage Free, Simple Installation and Easy Maintenance, No Spare Part

7. The service requiring Moderate to High Thrust Force is applicable

8. Suitable for harsh outdoor environments

DISADVANTAGE

1. Very expensive

2. Moving parts are expensive to maintain.

3. Fail-safe is possible with Spring or required accessory parts.

4. Unfamiliar with the plant operator as the most recent technology actuator

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● Examples of ESD (Emergency Shutdown)

► If you want detailed VIDEO about the picture above, I will send it to you by e-mail.

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FEATURE APPLICATIONADVANTAGE ● Non-Return Valve, so called Swing Check Valve, or

1. Electric/Pneumatic Power is not needed Non-Slam Check valve, Butterfly Check Valve mainly

2. It is safe from Fire Hazard

3. Easy installation

4. Simple operation with Hydraulic Cylinder and Counter Weight only

5. Counter weight adjustable valve closing time eliminates Hammering ("bang" closing phenomenon)

6. If necessary, it is possible to switch to Hydraulic Actuator by operation such as Hydraulic Pump / Valve / Multi Valve.

DISADVANTAGE

1. It can not be applied to a certain torque exceeding the limit of the weight of counter weight

2. Adjustment due to flow fluctuations is possible only manually at the site if required

3. It is not possible to operate in case of oil leakage, so particular attention is required.

◙ HYDRAULIC CYLINDER with Counter Weight

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