108-2SLF Fire Foam Pressure Relief Valve
Fire Foam Pressure Relief Valve, This valve automatically relieves excess foam pump discharge pressure to prevent the pressure exceeding the rating of the ﬁre system components. The engineered SLF (sense line ﬂush) feature assures accurate pressure control by continuously ﬂushing the pilot sensing chamber (ﬂow through design).
FEATURES & BENEFITS
Limits maximum foam system pressure
Opens quickly; accurately maintains pressure
Adjustable: 20-80, 65-180, or 100-300 psi
Pilot operated main valve
Pressure setting is adjustable with single screw
Sense line ﬂush can be manually selected
Factory tested and pre-set to requirements
Globe or angle pattern
Wide range of materials available
CERTIFICATION & COMPLIANCE
• ANSI FCI 70-2 Class VI seat leakage class
• ABS type approva
Pump & Water Tanks
Fire Suppression Systems
Petrochemical, Oil & Gas Installations
Power Generation, Transformer & Transmission Plants
Onshore / Offshore
The normally closed, spring-loaded pilot, sensing pump downstream pressure, opens when pressure exceeds the spring setting, allowing the main valve to open. As the pump pressure increases, the pilot opens further, causing the main valve to do the same. Pressure is maintained at the controlled set point over a wide range of flows regardless of back pressure in the downstream piping. The valve closes gradually as pressures decreases below the set point.
The Model 108-2SLF consists of the following components, arranged as shown on the schematic diagram:
 Model 65 Basic Control Valve, a hydraulically operated, diaphragm actuated, globe or angle valve that closes with an elastomers-on-metal seal.
 Model 1330SLF Pressure Relief Pilot, a 2-way, normally closed pilot valve that senses upstream pressure under its diaphragm and balances it against an adjustable spring load. An increase in pressure tends to make the pilot open.
 Model 126 Ejector, a tee fitting with a fixed orifice in its inlet port. It provides the proper pressure to the diaphragm chamber of the main valve depending upon the position of the pressure relief pilot.
 Model 141-3 Flow Control Valve, a needle-type valve that provides adjustable restricted flow in one direction and free flow in the opposite direction. On the 108-2SLF it acts as a closing speed control.
 Model 300777 Orifice Fitting, a key component of the sense line flush design.
 Model 141-4 Ball Valve, provides manual selection of the sense line flush feature. It is normally closed and is opened to flush the sense line and pilot diaphragm chamber.
 Model 155 Visual Indicator, (optional) provides indication of the valve’s position at a glance