Water, Air, Steam Systems 3/4'' PN16 Stainless Steel 304 Safety Relief Valve

Safety relief valve - A pressure relief valve characterised by rapid opening or pop action,

or by opening in proportion to the increase in pressure over the opening pressure, depending

on the application, and which may be used either for liquid or compressible fluid.

Safety Valve - How They Work

A safety valve is a safety device designed to control the pressure in the system. If the pressure is

uncontrolled, it can build up in the system causing equipment failure, explosions or fire hazards.

This valve is designed to open at a predetermined pressure to avoid equipment failure as a result

of being subjected to the pressure that exceeds there design limits. Once the valve opens due to

excess pressure, the media is discharged until the pressure drops to it's acceptable limit and the

valve is than automatically closed.

Standard safety valve, complete with carbon filled PTFE valve seal, closed bonnet, gastight Outlet:

female thread Rc 3/8 acc. to ISO 7/1 "cleaned and degreased for oxygen service"

Applications:

Provided as safety device for protection against thermal expansion in pipeworks and parts of facilities.

Approved for air gases, vapours and cryogenic liquefied gases incl. LNG.
Working temperature: -196°C / -321°F (77K) up to +65°C / +149°F (338K), suitable for horizontal installation

Important terminology

• Overpressure: The excess pressure over the set pressure of the safety valve.
• Operating pressure: The pressure at which the system works under normal operating conditions.
• Set pressure: The pressure at which the disc begins to lift, and the safety valve opens.
• Lift: The measure of distance the disc has moved from it's closed position to the position that is required for discharge.
• Backpressure: The pressure built up on the outlet of the safety valve during the flow. Back Pressure = Built up backpressure + Superimposed back pressure.
• Built up backpressure: The pressure at the outlet once the safety valve has opened.
• Superimposed back pressure: The pressure at the outlet of the closed safety valve.
• Maximum allowable working pressure (MAWP): The maximum allowable pressure at a designated temperature under normal operating conditions. Simply, MAWP is the maximum pressure that the weakest component of the pressure device can handle.
• Blowdown: The difference between the actual pressure at which the disc lifts and actual pressure at which the valve closes. It is generally expressed in percentage.
• Blow off capacity: The rate at which the excess pressure can be released.