Ames Fire & Waterworks 925GS Stainless Steel Pressure Relief and Surge Anticipator Control Valve - Manual

01/06
920 Series Model
8550 Hansen Road • Houston, Texas 77075 • (Ph) 713.943.0688 • (Fx) 713.944.9445 • www.amesfirewater.com
Operation
The AMES Model 925 / 625 Combination Surge Anticipator and Pressure Relief Control Valve is designed
to minimize the effects of water hammer and pressure surges resulting from: 1) Normal pump starting and
stopping operations or 2) Mechanical or electrical power failure situations. The valve senses hydraulic
pressure changes directly from the pump station discharge header, and opens to relieve pipeline surges
when pump station discharge header pressure falls below the adjustable spring setting of the low pressure
opening pilot OR exceeds the adjustable spring setting of the high pressure relief pilot. These two pressure
conditions occur during normal pump starting and stopping operations or when an active pumping cycle is
interrupted by electrical or mechanical failure.
High Pressure Relief Operation: When discharge header pressure exceeds the adjustable setpoint, the
high pressure relief pilot opens, venting main valve cover pressure downstream, causing the valve to quickly
open and dissipate the high pressure surge. When discharge header pressure falls below the adjustable
setpoint, the high pressure relief pilot closes, allowing pressure to fill the main valve cover chamber, slowly
closing the valve. This condition occurs during normal pump starting and stopping operations.
Low Pressure Opening Operation (Surge Anticipation): When discharge header pressure falls below
the adjustable setpoint, the low-pressure pilot opens and the drain pilot closes, “storing” main valve cover
pressure in the hydraulic accumulator. The main valve opens at an adjustable rate in anticipation of
the returning high-pressure wave. This condition occurs during a mechanical or electrical power failure
situation.
Valve Closing: When discharge header pressure recovers above the adjustable setpoint, the low-pressure
pilot closes, allowing header pressure to fill the main valve cover chamber. The main valve closes at an
adjustable rate to avoid creating additional pressure surges. The accumulator drain pilot opens, releasing
the “stored” main valve cover pressure.
If discharge header pressure does not “recover” above the low-pressure opening setpoint, the “stored”
pressure in the hydraulic accumulator allows the main valve to close, avoiding system siphonage or draining
the pumping system.
PRESSURE RELIEF and
SURGE ANTICIPATOR VALVE
925
625