HumbertTinker33

De Wikis en Educación

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última version al 14:09 21 feb 2012

Based on ASME Section VIII Division I, hydrostatic pressure is conducted with the pressure of merely one.More design pressure.

If 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 put on existing equipments and pipe lines to evaluate for leakage after being repaired or maintained. Hydrostatic job number increases during plant Change period. Because during those times, almost all of equipments are opened for checking, inspection, clean-up, repairing, replacing certain parts or performing internal modification.

The use of high pressure is the main method to obtain hazards linked to hydrostatic pressure test. Hydrostatic test stores energy. Underhand could damage the facilities and endanger worker's safety. You should have included this in your own hazard identification.

Safety Checklist:

In order to prevent accident from hydrostatic test operation, we have to make good preparation before perform test, through the pressurization process and depressurizing operation. These jobs must be made in the shape standard operating procedure. And listed below are the security checklists for every stage.

Hydrostatic test preparation:

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

• Hydrostatic test pressure and temperature standard are already clearly defined inside the related document.
• Supported documents such as P&ID and isometric drawing can be found and conform to as built facilities at the field.
• Pressure test planning has to be distributed to all relevant sections inside plant site at the very least two days prior to the execution date.
• Make good coordination among related sections that entail within the test.
• All test equipments and tools should be inspected for wear and damage.
• Pressure measurement tools are calibrated along with their statuses of calibration are still valid.
• Pressure gauges employed in quality plenty of capacity. The gauges are recommended to own 150% in the maximum allowable working pressure.
• Pressure to succeed gauge is safety type, with blowout back.
• Pressure gauges should be installed in a proper location then it can be easily read and don't create additional hazards on the hydrostatic test or expose personnels to the vessel being tested.
• Each of the temporary tools (including valve, fitting, hoses, flanges, blind plate, etc) must be rated over the absolute maximum hydrostatic pressure.
• Isolate other equipments and pipe lines that don't use in the hydrostatic test.
• Vents can be obtained and installed the top points to vent air. Look at the vent line before testing and make sure it isn't blocked.
• Choose drain valve at the cheapest point in order to totally empty the vessel and pipe.
• Safety relief valve has already been installed. Safety relief valve setting is 1.5 times maximum allowable working pressure.
• Safety relief valve is calibrated.
• Isolate quality area and surround it keeping the car safe line. Put appropriate safety sign as well area.
• Do not allow individual that doesn't have a relation with all the hydrostatic test, to penetrate the exam area.
• When possible perform test coming from a remote area.
• Ensure that all pipe and vessel supports are in good and also have been inspected.
• All hoses have to be restricted.
• Hot and cold levels have to be more than 16oC (60 F).
• The hydrostatic-pressurizing pump is done keeping the vehicle safe relief valve.
• Wear proper personal protective equipments.
• Do not start test if a issue is identified.
• Issue a piece safety permit by authorized personnel.

reference: hydrostatic valve