Safety Relief Valve
Designed to relieve excess pressure or thermal expansion of process fluids safely in pumps, pipe work, tanks, calorifiers, gas and oil separators, other process vessels and long pipes. Models are available for gas, steam, vapor and liquid applications.
Safety-relief valves may be considered as stop valves that close using a steady force insisting directly on the disc, thus no external actuator is needed.
When fitted in a pressurized system, they remain normally closed and open only if the force generated by the pressure is higher than the corresponding thrust insisting on the disc.
Safety valves are conceived to keep the pressure of the system, where they are fitted, under a stated value by discharging as much fluid as necessary for this purpose.
The force on the disc may be imposed through: a weight, a weight and a lever, a spring.
Weight loaded valves have a lift higher (and thus a higher flow) than spring loaded valves, being all other conditions unchanged, because the latter reacts proportionally to the lift while the former has a constant opposite force.
A pressure relief device is actuated by inlet static pressure and designed to open during an emergency or abnormal conditions to prevent a rise of internal fluid pressure in excess of a specified value.
The device also may be designed to prevent excessive internal vacuum.
The device may be a pressure relief valve, a nonreclosing pressure relief device, or a vacuum relief valve.
A safety valve is normally used with compressible fluids.
PRODUCT Features
• Full nozzle, full lift designs provide high discharge coefficients and high capacities.
• Broad selection of valve types: thermal, conventional, bellows, pop and modulating for gas or liquid service enables optimum valve selection.
• Wide range of materials provides solutions for any application.
• Lightweight construction reduces handling and shipping costs and benefits offshore service.
• Seat leakage integrity minimizes fugitive emissions.
• In-situ testing capability reduces maintenance costs.
• Low number of parts minimizes inventory and reduces maintenance costs.
• Valves conform to API 526 pressure/ temperature ranges, orifice areas and dimensions.
• Extensive accessory range enables valves to be adapted to meet specific code and application requirements.
• Worldwide certification.
A safety relief valve is a spring-loaded pressure relief valve that may be used as either a safety or relief valve, depending on the application.