Hydrotest (AG)

[sdomermpc]

can someone walk me through the procedure of Hydrotest? i read test pressure is 1.5 times the design pressure., how does Inspector find the value of design pressure, is there a specific documents which lists different pressure value of piping in plant? what are documents needed before one carry out hydro test? is there a special water for doing the test, how do we find the quality, is it normal to have specific quality is water, or can any type be used? what are instruments involved apart from pressure gauges, test manifold, blind flanges? Who is responsible for arranging of water on site? what is Cleaning, gouging, and drying? how long one should hold pressure?

[sdomermpc]

Hydrotest for above ground piping

[Marty Thompson]

This might help you

[hamid1469]

hi

[link Point to another website Only the registered members can access]
Shell procedure for pressure testing of piping

[sdomermpc]

thanks hamid n marty, does any of you have method statement for hydro testing from a Korean company like gs e&c for their gulf projects

[pollar]

thanks

[aragorn]

Thanks

[dungnqgl]

hi buddy.
the pressure test value are 1.5 or 1.25 (for asme b31.11) depended on your applicable standard. u should refer to Design description document for more detail.

[Jay_Piping Inspector]

i read test pressure is 1.5 times the design pressure., how does Inspector find the value of design pressure, is there a specific documents which lists different pressure value of piping in plant?

If your project is a refinery or power plant, the design pressure can be determined by Material Specifications by the client and can be shown in each Line class. A line class gives information about the pipe material properties, design pressure/temperature, size and ratings of pipe and fittings. A line list is also a document that summarizes all the line class and this document is an important part of your test package

what are documents needed before one carry out hydro test?

1. Isometric and P&ID drawings complete with test limits and indications if temporary spools are installed to replace instruments that are not to be included in the hydrotest
2. Safety Instruction Sheet (SIS)
3.Line List
4. Weld Summary (Very Important!!)
5. NDE Summary (All RT, PT, or any NDT test must be documented and will coincide with the weld summary)
6. Calibration Certificate for Pressure gauges, Pressure Relief Valves, Test Manifold, Water Quality certificate
7.Make sure that all punch list are rectified and that the line check was done and watch out for supports that require direct welding so check support details carefully
8.Work Permit, which should be the responsibility of the Construction group
9. Request for Inspection, from the QC inspector

is there a special water for doing the test, how do we find the quality, is it normal to have specific quality is water, or can any type be used?

You can request a third party company to perform test for water quality especially if the requirement is potable water or if it requires a chemical solution and keep the certificate and show to the client.It depends on client specifications on what criteria the water quality will be tested for.

what are instruments involved apart from pressure gauges, test manifold, blind flanges?

Pressure relief valve is important, other instruments that measure water temperature are also used.

Who is responsible for arranging of water on site?

The Construction supervisor or foreman can handle this..if you are a QC inspector you just verify the documents and the equipments to be used prior to hydrotest execution

what is Cleaning, gouging, and drying?

Cleaning can be chemical cleaning requirements for stainless steel pipes or the air blowing or water flushing as required. Gouging.. I haven't done that yet..Drying is sometimes called Lay-up in the Middle East..there are many methods but dry lay-up using dew point controlled air with the objective of obtaining a dew point temperature of -1 deg. Celsius at all exit points is most common. The type of lay-up is also determined by Material Specifications by client as per Line class.

how long one should hold pressure?

If standards are to be followed it should be not less than 10 minutes or longer depending on how long is the line. In my experience the client inspector requires at least minimum of 30 minutes.