Relief Valve

• General Info

  A relief valve is a safety device that protects pressurized systems from excessive pressure by automatically releasing any surplus. These valves are essential in preventing equipment failure and potential hazards, such as explosions or ruptures, by allowing fluid to escape when the pressure exceeds a predetermined limit.
  
  Key Components
  Body: The outer casing of the valve, typically made from materials like stainless steel, brass, or carbon steel, depending on the application and type of fluid.
  Spring: A spring mechanism that keeps the valve closed until the set pressure is surpassed.
  Piston or disc: The movable part that opens to release pressure. When the pressure exceeds the set point, the piston or disc lifts off the seat, allowing fluid to flow out.
  Adjustment Screw: This feature allows for the setting and adjustment of the valve's opening pressure.
  Outlet Port: The opening through which excess fluid is discharged when the valve activates.
  
  Types of Relief Valves
  Pressure Relief Valve (PRV): Designed to relieve excessive pressure in a system, commonly used in piping systems and storage tanks.
  
  Pressure Safety Valve (PSV): Similar to PRVs but specifically designed for high-pressure applications, such as steam systems and pressure vessels.
  
  Temperature Relief Valve: Specifically designed to relieve pressure due to excess temperature, often used in hot water heaters and boilers.
  
  Combination Valve: A hybrid that functions as both a pressure relief valve and a temperature relief valve.
  
  Pilot-Operated Relief Valve: Utilizes a smaller pilot valve to control the opening and closing of a larger valve, allowing for more precise pressure regulation.

• Specification

  Relief valves are used to protect systems from overpressure by allowing excess pressure to be released. They are available in a range of sizes, depending on the system requirements and the amount of pressure that needs to be relieved. Common relief valve sizes typically correspond to the pipe diameter and flow rate, and the sizes commonly available are:
  
  1/4-inch (6.35 mm)
  1/2-inch (12.7 mm)
  3/4-inch (19.05 mm)
  1-inch (25.4 mm)
  1.5-inch (40 mm)
  2-inch (50 mm)
  3-inch (80 mm)
  4-inch (100 mm)
  6-inch (150 mm)
  
  Relief valves can also come in larger sizes, especially for industrial or large-scale systems, with sizes ranging up to 12-inch (300 mm) or more, depending on the requirements of the system.
  
  The valve size chosen depends on factors like system pressure, the flow rate to be relieved, and the type of media (liquid, gas, steam). Always refer to the manufacturer’s specifications for the correct valve size to meet the specific application and pressure relief requirements.