Differential Pressure Control Valve

The SUNFLU differential pressure control valve for a constant control of the set nominal value is a 

proportional regulator which works without auxiliary energy.

Infinitely adjustable nominal value between 300 mbar and 700 mbar. The nominal value can be locked 

and is visible from outside. With concealed isolating facility and with ball valve for draining and filling, 

installation in the return pipe, oblique pattern model. 

Valve disc with soft seal. Valve body, bonnet and regulator housing made on bronze, valve disc and 

stem made of brass resistant to dezincification, O-rings, washer and diaphragm made of EPDM.

Installation of the regulator:

SUNFLU differential pressure control valve are installed in the return pipe. Installation is possible in any 

position provided the direction of flow conforms to the direction of the arrow on the valve body. The 

pipework has to be flushed thoroughly before installation of the differential pressure regulator. The 

installation of an “Y” type strainer is recommended. The capillary should be fitted above or horizontal to 

the supply pipe, to avoid blockage of the capillary by small particles, it should not be connected to the 

supply pipe from underneath.

Pressure test of the installation only with the capillary being connected.

Operation of the manual isolation:

The SUNFLU differential pressure control valve can be closed off manually, e.g. for servicing the 

system, and additionally acts as an isolating valve. To carry out manual isolation, remove locking screw 

from the handwheel and close the valve with a 3 mm Allen key with the capillary of the upper chamber 

of the diaphragm regulator being connected to the supply pipe.

Technical data:

Max.operating temperature : +120 °C Min.operating temperature : -20 °C

Max.operating pressure : 16 bar (PN 16)

Connection: Thread to EN 10226

Length of capillary: 1m

Differential pressure △P:300mbar - 700mbar

Below are examples of installation:

Differential pressure control valve / Brass Balancing valve

Setting and automatic regulation of the differential pressure in a riser.

Condition: Calculation of the mass flow and the corresponding differential pressure in the riser which 

shall be regulated.

Note: Simple setting of the required nominal value by turning the handwheel.