Pressure Relief Valves

Curtiss-Wright's selection of Pressure Relief Valves comes from its outstanding product brands Farris and Target Rock. We endeavour to support the whole life cycle of a facility and continuously provide custom products and technologies. Boasting a reputation for producing high quality, durable products, our collection of Pressure Relief Valves are guaranteed to provide effective and reliable pressure relief.

While some basic components and activations in relieving pressure may differ between the specific types of relief valves, each aims to be 100% effective in keeping your equipment running safely. Our current range includes numerous valve types, from flanged to spring-loaded, threaded to wireless, pilot operated, and much more.

View are full range of Pressure Relief Safety Valves below:

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Farris Target Rock

PRVs: Purpose, functionality, application.

Pressure Relief Valves are a safety device designed to protect a pressurized vessel or system during an overpressure event. An overpressure event refers to any condition which would cause pressure in a vessel or system to increase beyond specified the design pressure or maximum allowable working pressure (MAWP). The Pressure Relief Valve relieves prevents overpressure events by allowing the pressurised fluid or gas to flow from an auxiliary passage out of the system.

Below is an example of one our pilot operate pressure relief valves in action, the cutaway demonstrates who high system pressure is released.

Farris 3880 Pilot Operated Pressure Relief Valve:


Types of PRV

Curtiss-Wright provide a range of different Pressure Relief Valves based on two main types of operation: 

Spring-loaded PRV

Spring loaded safety valves rely on the closing force applied by a spring onto the main seating area.. The valve is closed as long as the force exerted by the spring is larger than the force created by system pressure.


  • Can operate at higher set pressures than pilot operated relief valves
  • Large range of chemical compatibility
  • High operating temperatures

Related Products: 2600/2600L series - Process Valve, 2700 Series - Process Valve, 4200 Series - Steam Safety Valve, 6400 Series - Steam Safety Valve,1890 Series - Process Valve, 1896 Series - Steam Safety Valve, 4700 Series - Steam Safety Valve, Model 600-DA - Steam Safety Valve, Model 600-SL - Safety and Relief Valve.


Pilot-Operated Pressure Relief Valves

Pilot-operated relief valves operate by combining the major relieving device (main valve) with self-actuated auxiliary pressure relief valves, also known as the pilot control. This pilot control dictates the opening and closing of the main valve and responds in proportion to system pressure. System pressure is fed from the inlet into and through the pilot control and ultimately into the dome of the main valve. In normal operating conditions, system pressure will prevent the main valve from opening.


When the pressure is below set pressure, the pressure differential is slightly positive on the dome size of the piston, which keeps the main valve in the closed position. When system pressure rises and reaches the set point, the pilot will cut off flow to the dome causing depressurization in the dome side of the piston. The pressure differential has reversed and the piston will rise, opening the main valve, relieving pressure.


When the process pressure decreases to a specific pressure, the pilot closes, the dome is reepressurized and the main valve closes.


  • modulating control PORVs minimize release of media 
  • increasing pressure helps to maintain the pilot's seal. Once the setpoint has been reached, the valve opens. This reduces leakage and fugitive emissions. 
  • often smaller footprint than spring-loaded valves
  • can work at operating pressures very close to the set point
  • PORVs are unaffected by backpressure 
  • PORVs with remote sensing options are cost effective solutions for PRV installations experiencing inlet pressure loss 

Related Products: 3800 Series - Process Valve, Model 600-PO - Steam Safety Valve


Additional Products: wireless monitored SmartPRV

At Curtiss-Wright we also provide solutions for pressure relief valve monitoring.  Historically, pressure relief valves have been difficult or impossible to monitor. Our SmartPRV featuring a 2600 Series pressure relief valve accessorized  with a wireless position monitor alerts plant operators during an overpressure event, including the time and duration.

Find out more hereSmartPRV Information