Hydrostatic examination is a type of NDT nondestructive examination and is one of the most favored method to identify leakage and cracks in boiler under water stress. Other NDT is such as magnetic particle examination MPT or penetrant examination PT are generally done to validate the level of damages after the leakage point has actually been discovered. Just water pressure is allowed for HT. Vapor or air is not enabled. Hydro itself suggests water. Water for all sensible objectives is incompressible, and the stress established by the hydrostatic pump could be relieved instantaneously by launching very small amount of water, which would take place on leakage happening. Air is compressible and can be hazardous under pressure. The exact same opts for steam. Under steaming conditions, any kind of failing of the structure would certainly result in the central heating boiler water flashing right into heavy steam, or steam leakages, subjected personnel to a threat of burn.
In Malaysia, the local jurisdiction, the Manufacturing facilities & Machinery Act 1970, stipulates that a central heating boiler shall be hydrostatically tested every 7 years where the accredited assessor will release a Certification of Hydrostatic Examination in 6th Set up, specifying the date, test pressure, holding time, result, and authorized secure working pressure. The Certificate is valid for 7 years till the following HT. Nevertheless, this is just a period, and your regional territories could call for different period. As a preparation for the HT, clean boiler waterside and fireside, nozzle flanges, manhole surfaces, and welding joints fire tube boilers. The security valve needs to be eliminated. Nevertheless, if somehow the safety and security shutoffs could not be gotten rid of, a test gag might be utilized adhering to the safety valves’ maker guidelines. Get rid of electric connections such as high pressure restriction switches and sensors. Keep in mind that when a HT is being related to a boiler, a calibrated test stress gage must be attached to the hydrostatic pump.
This precision examination gage shall have the accuracy of 0.5%. Countercheck it with the calibrated stress gage placed on the central heating boiler. Blind the nozzles by installing blind flanges or blind plates to fittings connection such as safety and security valves, major stop shutoffs, feed nozzles, mombrey links, and gage glasses. Rubber or normal gaskets will certainly do simply fine. Fill up with treated water for the whole volume of the boiler and vent air from the system. Usage water hose pipe and fill out through one of the leading nozzles up until water overruns from the nozzle. Due to the fact that the boiler might continue to be standby after the examination, it is necessary that the water in the central heating boiler is treated to avoid corrosion matching. Consult your regional chemical supplier for the treating method. The steel temperature level for HT shall not be much less compared to 60oF 16oC and not more than 120oF.