Thermal Safety Valve Manufacturer in India
Thermal safety valves are used to relieve pressure caused by liquid thermal expansion in blocked-in or isolated sections of piping and equipment. They are particularly relevant where a relatively small temperature increase can produce a significant pressure rise in an incompressible liquid. Speciality Valve manufactures thermal relief configurations for industrial liquid services, with construction and materials determined by the pressure, temperature and process medium.
Thermal Relief Valve Technical Range:
Where Thermal Relief Is Required?
Blocked-in liquid lines: Protects liquid trapped between closed isolation valves when ambient or process temperature rises.
Pump discharge sections: Addresses thermal expansion in isolated liquid-filled piping where no normal flow path remains.
Heat exchanger circuits: Protects liquid-filled exchanger sections during shutdown or isolation.
Liquid transfer piping: Useful where trapped product can warm after valves are closed.
Jacketed equipment: Can protect contained liquid from pressure increase caused by external heating.
Thermal relief is generally associated with a relatively small relieving flow compared with the capacity required for major gas or vapour overpressure scenarios. The protected liquid volume, coefficient of thermal expansion and expected temperature rise therefore become important inputs to the relief calculation.
Set Pressure and Relief Capacity:
Thermal relief sizing differs from conventional gas or steam safety-valve sizing because the relieving load is generally associated with liquid expansion rather than a large process-flow contingency.
Key parameters include:
Set pressure: Must be coordinated with the protected equipment's allowable pressure.
Accumulation: The permitted pressure rise during the relief event must follow the applicable design code.
Thermal expansion rate: Depends on liquid properties, temperature rise and the volume of trapped liquid.
Discharge pressure: Outlet pressure and back pressure must be considered when evaluating valve performance.
Relief capacity: The valve must pass sufficient liquid to control the pressure generated by the credible thermal expansion case.
Inlet pressure loss: The inlet arrangement should minimise restrictions that could affect the pressure available at the valve.
Discharge routing: Relief liquid should be directed to a suitable return, drain or collection point according to the process design.
Materials Used for Liquid Thermal Service:
Common Material Grades:
Actual grade availability depends on the valve construction and project specification. Seat and trim materials may differ from the body material where additional corrosion resistance or sealing performance is required.
Applicable Codes and Testing:
ASME BPVC Section XIII: Requirements for overpressure protection devices where applicable.
API 520: Relevant to sizing and selection of pressure-relieving devices for applicable services.
API 527: Seat-tightness testing requirements for applicable pressure relief valve designs.
API 521: Relevant where the thermal relief discharge forms part of a broader pressure-relieving system.
Pressure testing: Shell and seat tests should follow the applicable product specification and purchaser requirements.
For a thermal relief requirement, share the trapped-liquid volume, operating temperature, set pressure and process medium with our team for a suitable valve configuration and quotation.
