Pressure relief and pressure retention valves, type 1400

The valve keeps an inlet pressure (p1), set at the control valve, constant, irrespective of a fluctuating flow. If the inlet pressure (p1) exceeds the pre-set pressure, the valve quickly opens. The closing process is slow thereby preventing any surges in pressure – the pressure
can be set as standard in the range 2 to 16 bar.

Application: Maintaining the network pressure and protecting against excess pressure

Variants: Electrically controlled, with backflow prevention, with float control and combinations thereof

Physical characteristics

The main valve is a hydraulically operating diaphragm valve. The work energy is the inherent medium.
Most valve types operate purely hydraulically without any foreign energy.


To use in drinking water systems (other media after consultation)
Reduction in pressure to supply the network
Emergency feed into a second network (network connections)

Mode of operation


The pressure relief valve maintains constant the pre-set inlet pressure (p1). Any excess system pressure is relieved by fast opening of the valve. The closing procedure is slow in order to avoid shock pressure loads. Variable flow rates have no effect on the maintained pressure which is regulated by the control valve. The overpressure or maintained pressure can be set within the range of 2 bar to 16 bar (standard design)

Product information

To calculate the dimensions of the valve please refer to the following information:
Maximum and minimum inlet pressure (static and dynamic pressure ratios)
Desired outlet pressure
Maximum and minimum flow rates
Possible requirement for extinguishing water
Available line diameters and lengths
Construction of the valve (straight or angle design)
For the calculation basis, information on the loss of pressure and the characteristic values of the valve, please refer to the end of Chapter E.


Design according to DIN EN 1074
Construction length acc. to DIN EN 558
Flange mass according to DIN 1092-2, to PN 25 DN 300
Pressure levels: PN 10 or PN 16 to DN 300, PN 25 to DN 200, higher pressures on request.
Nominal widths DN 50, DN 80, DN 100 and DN 150 available in angular design
Nominal widths 1 ½" and 2" with threaded connection (female thread)
Medium temperature up to 40°C


- Basic valve EN-GJS-400

- Epoxy coating (min. 250 µm) acc. to GSK, RAL 5012

- Spindle unit INOX, EN-GJS-250

- Control line, fittings and control filter stainless steel

- Control valve INOX

Installation and assembly

Shut–off valves should be fitted on both sides of the valve and a dirt trap should be installed on the inlet side of the valve. Depending on the installation situation, a mounting/dismounting adapter and an aeration and ventilation system should be provided.


Maintenance-free, non-rusting valve seat
Pressed-in seat
EWS-coating according to RAL GSK


Instruction manual


Go back