differential pressure control valve cim 767 - alma-valves.ie · page 1 of 13 technical leaflet cim...

of 13 Technical Leaflet Cim 767

Revision 0 Issue 06/2011

TECHNICAL INFORMATION

Differential pressure control valve CIM 767 Description Cim 767 are designed for automatic control

of differential pressure (DPCV) in order to

maintain constant differential pressure

between two points of the installation. The

flow rate of each branch of a circuit may

change according to temperature

requirements. Since flow rates depend on

∆p, the main feature of Cim 767 is to

maintain constant the nominal flow rate

through open terminal units, regardless

partial or full closing of them. Cim 767 is

suitable for heating and cooling installations,

assuring a good modulating control and

reducing the noise risks coming from two-ways control valves, when high ∆p values might be present in the

installation. Cim 767 is normally coupled with a partner balancing valve placed on feed line, enabling the

flow regulation.

Cim 767 differential pressure control valve is made of “CR – Corrosion Resistant” brass with female-female

threads according to ISO 228 standard and it is suitable for working pressure up to 16 bar, within the working

temperature range of -10°C and +120°C.

They are manufactured in sizes from DN 15 up to DN 50 and work properly up to a maximum differential

pressure of 400 KPa. The maximum flow rate is 15 m3/h.

Picture 1



The main features of Cim 767 are as follows:

• Keeping of selected ∆p at the ends of the circuit, by operating on screw of the handle of the valve with

Allen key.

• Differential pressure control at the ends of the valve, using a ∆p measuring instrument connected to

binder points.

• Noise clearance when installation is in overpressure conditions.

• Reduction of balancing costs, improved energy saving and high environmental comfort.

• Easy flushing procedure thanks to quick and simple removal of differential pressure control cartridge,

placed inside valve body.

• Reduced installation dimensions thanks to compact valve construction, which does not require inlet and

outlet straight pipelines to stabilize the flow.

Installation Before installation of Cim 767, check that inside the valve and the pipes there are no foreign matters which

might damage the tightness of the valve.

Burr pipe connections after having threaded them and distribute the sealing material on pipe threads only

and not on valve threads.

Make sure that required flow rate is within operating range of the valve. Cim 767 shall be installed on the

return line either on horizontal or vertical position, but following the arrow direction casted on valve body,

which shall be the same as the flow one. Cim 767 is coupled with partner valve Cim 787DP, installed on

feed line by a copper capillary pipe.

For assembly purpose, use a spanner, not a pipe

wrench, by applying necessary working torque

only on the valve end nearest to the pipe. This

helps get a firmer grip and avoids potential

damages to valve body. Make sure that pipe

threading length is not longer than valve threads.

After DPC cartridge removal, it is possible to flush

the system branch where the valve is installed;

when flushing process is over, reposition the DPC

control cartridge.

Cim 787DP

Cim 767

Picture 2



Valve regulation ∆p regulation of Cim 767 valve (see picture 3) is carried out by Allen key in 4 mm.

The relation between flow rate, ∆p of feed line and return line and screwing turns of regulating Allen screw

are given by the tables stated on following pages (see “Graphs and Tables”).

∆p increase and decrease is reached by turning clockwise or anticlockwise Allen screw respectively (see

picture 3).

During regulation of differential pressure, the valve

shall be set to minimum value to proceed with turns

numbering; after that, the valve shall be regulated

according to tables.

∆p of the system is measured through differential

manometer Cim 726 with the two sensors, red and

blue, which are inserted in binder points PF- and P+

respectively (see picture 4).

Flow rate of the system is regulated through a

partner balancing valve Cim 787DP, by

measuring the difference in pressure between

points PF+ and PF- and referring to the graphs

of Cim 787 valve.

Flow rate drop of Cim 767 valve under service

is shown when the two sensors of measuring

device are inserted in the binder points of the

said valve. Maintenance

As a rule, the balancing valve does not need

any maintenance. In case of replacement or need of disassembling of some components of the valve, f.i. for

flushing the cartridge of differential pressure, make sure that the installation is not under service or pressure.

Picture 3

Picture 4



The following table shows the dimensions of full range of valves Cim 767.

DN A B C CH

1/2” 55 79 95,5 27

3/4” 55 79 96,5 32

1” 75 91 132 39

1”1/4 75 91 132 47

1”1/2 87 97 144,5 54

2” 90 106 155 68

Picture 5



Graphs and Tables CIM 767 - 1/2” DN 15 Low ∆p = 5÷30 KPa

∆p differential pressure according to number of turns of Allen screw

FLOW RATE Control ∆p range (KPa) l/h l/s gpm*

Kvs

5 ÷ 30 50 ÷ 600 0,014 ÷ 0,167 0,22 ÷ 2,65 3,6

* The “gpm” values are corresponding to US gallon per minute.



CIM 767 – 3/4” DN 20 Low ∆p = 5÷30 KPa



Kvs

5 ÷ 30 100 ÷ 1000 0,028 ÷ 0,278 0,44 ÷ 4,41 4,0




CIM 767 – 1” DN 25 Low ∆p = 5÷30 KPa



Kvs

5 ÷ 30 600 ÷ 2500 0,167 ÷ 0,694 2,65 ÷ 11,02 9,5




CIM 767 – 1/2” DN 15 High ∆p = 20÷60 KPa



Kvs

20 ÷ 60 100 ÷ 1200 0,028 ÷ 0,333 0,44 ÷ 5,29 3,6




CIM 767 – 3/4” DN 20 High ∆p = 20÷60 KPa



Kvs

20 ÷ 60 150 ÷ 2000 0,042 ÷ 0,556 0,66 ÷ 8,82 4,0




CIM 767 – 1” DN 25 High ∆p = 20÷60 KPa



Kvs

20 ÷ 60 700 ÷ 4200 0,194 ÷ 1,167 3,09 ÷ 18,52 9,5




CIM 767 – 1”1/4 DN 32 High ∆p = 20÷80 KPa



Kvs

20 ÷ 80 1000 ÷ 5000 0,278 ÷ 1,389 4,41 ÷ 22,05 11,4




CIM 767 – 1”1/2 DN 40 High ∆p = 20÷80 KPa



Kvs

20 ÷ 80 3000 ÷ 8000 0,833 ÷ 2,222 13,23 ÷ 35,27 16,4




CIM 767 – 2” DN 50 High ∆p = 20÷80 KPa



Kvs

20 ÷ 80 5000 ÷ 15000 1,389 ÷ 4,167 22,05 ÷ 66,14 17,9


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