ThePipingMart Blog Metals Safety Valve and PRV (ASME/API 526)

Safety Valve and PRV (ASME/API 526)

Safety Valve

A safety valve is protection equipment that is invented to control the pressure in operation. This valve protects people and the environment from overpressure that may produce explosions or different damages. When a set pressure exceeds, a safety valve opens automatically. A safety valve is the last useful device that occurs when other protection devices have failed. When overpressure is identified, the disc of the valve opens to release the fluid and restores the normal pressure situation in the piping operations. After reducing pressure below a set pressure, the valve closes again.

A safety valve has no actuators or external devices for open or close operations. Safety valves are beneficial for gas storage tanks, pressure vessels, boilers, and piping systems. There are different standards for safety valves, such as ASME or API 526.

Types of safety valves

Spring-loaded safety valve

The spring-loaded safety valve is produced to accommodate overpressure protection in the system actuated device. The spring force is equivalent to or higher than the inlet media force used on the closed position disc. A spring-loaded safety valve is suitable for applications that do not have redundant back pressure in the system.

Balanced bellows safety valve

A balanced bellows safety valve is the same as a spring-loaded safety valve, but it has a bellow. The bellow is a crucial part to minimize the force of backpressure. This type of valve is utilized when the backpressure is exceptionally high, and the typical spring-loaded safety valve is not perfect to use.

Pilot operated safety valve

A pilot-operated safety valve has an additional pilot hole. If the set pressure overtakes the inlet pressure, then the valve remains closed. When the inlet pressure rises beyond the set limit, the pilot opens and allows the media to flow.

Pressure Relief Valves

A Pressure Relief Valve is a protection device that is designed to shield a pressurized vessel during exceed pressure conditions. An overpressure condition is a condition of pressure in the system which extends beyond the specified pressure range or maximum allowable working pressure in the system. The main goal of a Pressure Relief Valve is to guard life and resources by releasing fluid through an overpressurized vessel. To control fluid system variables like temperature, pressure, and flow, there are many pneumatic, electronic, and hydraulic systems. Each of these pressure relief systems needs any type of power sources like electricity or compressed air. A pressure Relief Valve is durable and capable of use in a tough time. This Valve is especially beneficial to use during a power failure when the controls of the system are non-functional.

Types of Pressure Relief Valves

Pilot-Operated Pressure Relief Valve

A pilot-operated Pressure Relief Valve has a primary relieving device, which is combined with and managed by a self-actuated auxiliary valve.

Power-Actuated Pressure Relief Valve

This type of pressure Relief Valve has a primary relieving device that is connected with and regulated by an external source of energy.

Temperature-Actuated Pressure Relief Valve

A temperature-actuated pressure Relief Valve is actuated by outside or inside temperature or pressure on the inlet side.

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