The boiler safety valve is a vital safety component in the safe operation of the boiler, and its accurate and reliable opening is extremely critical to maintaining the safe operation of the boiler. In this paper, we will discuss in depth the common faults of boiler safety valves and their troubleshooting methods in daily operation.
Boiler safety valves, as an important protection valve, are widely used in various types of pressure vessels and piping systems. When the pressurized vessel (system) reaches the preset upper pressure limit, the safety valve can automatically sense and open to discharge the excess medium, and then automatically close to ensure that the pressure vessel operates within a safe and reliable pressure range and to prevent the occurrence of major safety accidents. The normal operation of the safety valve is not only related to the safe use of boilers and other pressure vessels, but also directly related to the safety of people’s lives and property. Therefore, for the common failure of boiler safety valves, we must attach great importance to and timely solution.
Boiler safety valve common faults and troubleshooting methods
Safety valve leakage
Fault description: In the boiler under normal operating pressure, the valve flap and the valve seat sealing surface leakage occurs beyond the allowable range.
Causes and solutions:
Dirt on the sealing surface: use a lifting wrench to open the valve several times to flush out the dirt.
Damage to the sealing surface: according to the degree of damage, repair by grinding or turning and then grinding to ensure that the sealing surface flatness and finish are up to standard.
Damaged concentricity of parts: reassemble or exclude the pipeline additional load.
The opening pressure is close to the normal pressure of the equipment: adjust the opening pressure appropriately to avoid leakage.
Spring relaxation: replace the spring or the whole valve, if caused by improper adjustment, tighten the adjustment screw.
Safety valve return pressure is too low
Fault description: cause a large amount of medium overtime discharge, resulting in energy loss.
Cause and solution:
Large amount of steam discharge: close the throttle valve, reduce the medium flow, reduce the kinetic energy pressure zone pressure.
Spool and guide sleeve fit gap is not appropriate: check and adjust the fit gap, increase the flow area.
Valve body combined surface leakage
Fault description: the upper and lower valve body combined surface leakage.
Cause and solution:
Insufficient bolt tightness or tightening bias: adjust the bolt tightness to ensure good sealing of the combined surface.
Toothed gasket does not meet the standard: Replace the gasket that meets the standard.
Poor flatness of the combined surface of the valve body or gasketed by impurities: grind the combined surface to meet quality standards, clean up impurities.
Delayed return of safety valve
Fault description: After the impulse safety valve is seated, the main safety valve is delayed for too long.
Cause and solution:
Large vapor leakage from piston chamber: open the throttle valve opening or increase the throttle orifice diameter to reduce the pressure inside the piston.
Large friction between moving parts and fixed parts: adjust the fit clearance to within the standard range.
Safety valve chattering
Fault description: The safety valve shakes in the discharge process.
Reason and solution:
Valve discharge capacity is too large: choose the rated discharge capacity close to the equipment necessary to discharge the valve.
Inlet pipe caliber is small or resistance: Ensure that the inner diameter of the inlet pipe is not smaller than the valve inlet diameter, reduce the resistance of the inlet pipe.
Large resistance of discharge piping: Reduce the resistance of discharge piping and back pressure.
Following the above recommendations will ensure the normal operation of the boiler safety valve and improve the safety and reliability of boiler operation.
