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Based on ASME Section VIII Division I, hydrostatic pressure is completed with the pressure of 1.Five times design pressure.

In case a vessel is design for holding 1.0 kg/cm2.g pressure, the hydrostatic pressure test needs to be done at 1.5 kg/cm2.g.

Hydrostatic test is also used on existing equipments and pipe lines to evaluate for leakage after being repaired or maintained. Hydrostatic job number increases during plant Turnaround period. Because during those times, nearly all of equipments are opened for checking, inspection, clean-up, repairing, replacing song or performing internal modification.

Using high pressure is the main way to obtain hazards associated with hydrostatic pressure test. Hydrostatic test stores energy. Underhand could damage the facilities and endanger worker's safety. You should have included this to your own hazard identification.

Safety Checklist:

To avoid accident from hydrostatic test operation, we need to make good preparation prior to perform the test, throughout the pressurization process and depressurizing operation. These jobs needs to be made in the shape standard operating procedure. And allow me to share the protection checklists for each and every stage.

Hydrostatic test preparation:

Specification sheet from the equipments or pipe line, which mentions pressure and temperature designs can be obtained and finish.

reference: hydrostatic valve
 * Hydrostatic test pressure and temperature standard already are clearly defined inside related document.
 * Supported documents including P&ID and isometric drawing are available and mould to as built facilities in the field.
 * Pressure test planning should be given to all relevant sections in the plant site a minimum of 2 days ahead of the execution date.
 * Make good coordination among related sections that involve within the test.
 * All test equipments and tools will probably be inspected for wear and damage.
 * Pressure measurement tools are calibrated in addition to their statuses of calibration are still valid.
 * Pressure gauges used in quality plenty of capacity. The gauges are recommended to possess 150% of the maximum allowable working pressure.
 * The pressure gauge is safety type, with blowout back.
 * Pressure gauges must be installed with a proper location then it can be simply read and do not create additional hazards on the hydrostatic test or expose personnels to the vessel being tested.
 * All the temporary tools (such as valve, fitting, hoses, flanges, blind plate, etc) should be rated over the most hydrostatic pressure.
 * Isolate other equipments and pipe lines that won't use in the hydrostatic test.
 * Vents can be purchased and installed our prime points to vent air. Check the vent line before testing and make sure it isn't blocked.
 * Choose drain valve at the lowest time order absolutely empty the vessel and pipe.
 * Safety relief valve is already installed. Safety relief valve setting is 1.5 times maximum allowable working pressure.
 * Safety relief valve is calibrated.
 * Isolate the test area and surround it with safety line. Put appropriate safety sign at this area.
 * Do not let person who doesn't have a relation with all the hydrostatic test, to get in test area.
 * Whenever possible carry out the test from your remote area.
 * Make certain that all pipe and vessel supports are in good and still have been inspected.
 * All hoses must be tied down.
 * Water temperature have to be more than 16oC (60 F).
 * The hydrostatic-pressurizing pump is done with safety relief valve.
 * Wear proper personal protective equipments.
 * Tend not to start the exam if the dilemma is identified.
 * Issue a piece safety permit by authorized personnel.