Double Chamber Diaphragmatic Valves


GEMAK created the design of this series of valve AS-A in order to eliminate the problems, found to the irrigation-water supply and pumping networks. AS-A series valves are hydraulically operated by means of a diaphragm which is located to the interior of the valve. Their regulation does not need any special knowledge. By mounting various pilots or three-way electromagnetic valves on their body, a large range of applications is achieved and all demands for regular and soft operation as well as for total protection of the waterworks are covered. Such as:

  • Anti-hammer shock valves, Surge control Valves
  • Pump controlling valves with automatic stop of the pump's operation
  • Level Control and Flow Control Valves
  • Non-Return Valves
  • Pressure reducing and Sustaining Valves
  • Tele-controlled valves used for the automation of the pumping, tanks, irrigation and water supply networks.

By using additional equipment we can regulate the opening and closing speed of the diaphragm from 0.2 up to 180sec creating ideal conditions for the safety and protection of pump stations and water networks. The valve series AS-A is available in two types: 1) Type Υ double chamber and 2) Angle shaped type with single and double chamber

The valves of the double chamber give the ability for multiple applications and smooth closing and operating (T=0.2sec-180sec) and therefore the creation of even a small pressure surge caused by the valve itself, is avoided. The valves of the single chamber have a limited margin of applications but they give the same safety and operation conditions as those of the double chamber, when they are used for the regulation of pressure and the immediate relief of pressure.


  • Irrigation
  • Water supply
  • Pump stations
  • Fire fighting netoworks

Using hydraulic diaphragmatic valve series AS-A we achieve:

  • Accurate regulation and control of the installation: pumps, pipelines, etc
  • Smooth and secure closure without leakages
  • Maintenance without being removed from the pipeline.
  • It is not worn out
  • Lubrication
  • Long life time of the installations
  • Secire operation of the pump, which is regulated by the valves so that it operates according to the cosntructor's preset limits. In case of line break the valves protect both the pump and the drill, as they close immediately when the pre-set lemits are surmounted.
  • Avoid caviation risks
  • Protect the drill from overpumping which causes serious damages.
  • Replacement of heavy and old technology consturctions with low cost and more effective operation.

Diaphragmatic valves can function, either electrically on ON-OFF conditions or hydraulically with capability of proportional control operation, (opening closing from 0,2sec to 180sec).



Diaphragmatic valves series AS-A with double chamber are constructed in two different configurations:
1. type Υ , series AS-A/Y
2. angle configurationM series AS-A/T

Due to their special design, maximum flow with minimum losses is achieved. The material used for the body's construction is ductile iron of spheroidal graphite GGG40/50 DIN 1693/ EN 1563. The main part of the internal mechanism, i sthe diaphragmatic actuator. The actuator's diaphragm is a membrane, made of nyln reinforced neoprene of high resistance and flexibility. This, divides the chamber, which is bethween the actuator's base and the cover, into two parts which are fluctuated according to the accepted rate of pressure. The mebrane is tighth to the end, with stainless steel bolts and held by two discs, made of copper DIN 1705 CuSn12 or steel GS45.The sealing disc is copper DIN1705 or steel GS45 with an elastic gasket made of EPDM for absolute water tightness and long life time. Between the actuator's base and the sealing disc, a stainless steel AISI 316 spring is placed which presses the sealing disc tighly. By connecting different pilots and electromagnetic valves we can acheive various application s for the smooth operation of the network.

The difference in pressure which appears in te two chambers of the actuator, through the pilot and the pressure inlet, is responsible for tha axial movement of he mechanism and the automatic operation. The valve will open when the inlet pressure exceeds the outlet forces of hte upper diaphragm and sping. In the case of equality between the outlet pressure and the regulated pressure, the valve tends to close, due to the pressure caused by the spirng. This operates as as check valve and closes totally when the inlet pressure is lower than the regulated outlet pressure.

More attributes

Valve configuration 'Υ': DN50 - DN450 (bigger sizes only uppon request)
Valve angle configuration: DN50 - DN100
Working Pressure : 10 bar -16 bar -25bar (for high pressures the piston type valve is recommeded)
Working Temperature : -10oC up to 80oC