Relief Control Valve or Pressure Relief Valve (PRV) is a type of safety valve used to control or limit the pressure in a system. In other cases, the equipment must be protected from experiencing an internal vacuum (i.e., low pressure) that is lower than what the equipment can withstand. Control Valve is a type of valve used to control flow, pressure, temperature, and liquid level by opening/ fully closed or partially opened/closed in response to a signal received from the controller which compares the “setpoint” to a given value “process variable”, the Relief Valve, is used to regulate the working pressure in the system and also prevent overload or overpressure hydraulic circuit capabilities.