Pressure Sustaining Valves 

The model 1200 pressure sustaining valve is a hydraulically operated, diaphragm actuated automatic control valve. When installed online, they sustain minimum backpressure thus prioritizing pressure zones, preventing line emptying, and pump overload.

The model 1200 Sustaining valve is a normally closed valve that is manually adjusted to open once upstream pressure reaches a preset value. The valve opens to maintain upstream pressure at that value. Once upstream pressure falls below the set point the valve closes slowly to a drip tight position.

Operating Principals of ACVs

Valve Closing: When the pilot closes water is trapped inside the bonnet and the main valve disc will be forced to close.

Valve Opening: When the pilot opens water is released from the bonnet allowing the main valve disc to open.

Valve Modulating: The main valve will mimic the small pilot valve. When the latter partially closes the main valve does the same and vice versa. The pilot valve reacts to a change in external signal received from the system. This signal might cause the pilot valve disc to partially close (hence closing the main valve) or to partially open.

Material Standards 

1. Body —— Ductile Iron EN-GJS-500/7  Or  Ductile Iron EN-GJS-400/12

2,6,8. Isolation valve —— Nickel plate copper alloy (Optional SS316)

3. Strainer —— Stainless steel SS316

4. Restriction —— Stainless steel 316

5. Needle Valve —— Stainless steel 316

7. Pressure Sustaining Pilot —— Stainless steel 316