SUGGESTION TO DETERMINE HYDRO TEST PRESSURE
SUGGESTION TO DETERMINE HYDRO TEST PRESSURE
(OP)
A 50KM LENGTH OF 10" DIA(WALL THICKNESS 7.8MM,C.S., ASTM A53 GR.B) OIL EXPORT PIPELINE IS REPAIRED WITH REPLACEMENTS OF SECTION OF PIPES WHICH ARE LESS THAN 3MM THICKNESS. OPERATING PRESSURE OF THE LINE IS 200 PSI. HYDROSTATIC TEST IS PLANNED.IS IT ADVISABLE TO PRESSURISE UPTO 600 PSI? WHAT IS THE SUGGESTED HYDRO TEST PRESSURE?





RE: SUGGESTION TO DETERMINE HYDRO TEST PRESSURE
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RE: SUGGESTION TO DETERMINE HYDRO TEST PRESSURE
RE: SUGGESTION TO DETERMINE HYDRO TEST PRESSURE
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RE: SUGGESTION TO DETERMINE HYDRO TEST PRESSURE
This distinction makes a large difference.
Also, please consider using both upper and lower case keys. It makes it easier for others to read. Thanks
Patricia Lougheed
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RE: SUGGESTION TO DETERMINE HYDRO TEST PRESSURE
Old pipes of < 3mm thickness were replaced with pipes of 7.8mm thickness. Please note old pipe sections of thickness between 3mm and 7.8mm were not attended.
RE: SUGGESTION TO DETERMINE HYDRO TEST PRESSURE
in accordance with B31.4 Liquid Pipeine Code,
and using a design factor of 0.72,
AND
IF YOU HAVE AT LEAST 1.5 mm wall thickness,
Using a test factor of 1.25 x Operating Pressure,
You could test at 1.25 x 200 Operating Pressure = 250 psig minimum test pressure.
Theoretical yield pressure of 1.5 mm x Grade B, is 329 psig, so DO NOT test to 600 psig.
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RE: SUGGESTION TO DETERMINE HYDRO TEST PRESSURE
It appears that RajVas' minimum pipe wall is 3mm (as everything below was replaced.)
Patricia Lougheed
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RE: SUGGESTION TO DETERMINE HYDRO TEST PRESSURE
It may be so, but it doesn't matter anyway because of the desired 200 psig operating pressure. 1.5 mm will permit an operating pressure of 200, as long as Raj tests to 250 (min) psig. Therefore, and in any other case, even those with wall thicknesses above 1.5 mm, there is no point going over the minimum required test pressure of 250 psig (according to B31.4) any more than you have to. A 250 psig min test is all that is needed to permit operating to 200 psig.
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RE: SUGGESTION TO DETERMINE HYDRO TEST PRESSURE
Could you please tell me what is the test pressure & suggested operating pressure for the 3mm thickness trunk pipeline according to B31.4?
RE: SUGGESTION TO DETERMINE HYDRO TEST PRESSURE
Are you implying that you (electrical) are making decisions for hydrotesting piping for which you do not have access to the appropriate code? How much money is at stake here and how much does a copy of B31.4 cost? Buy the code and have a mechanical engineer within your organization study it...
jt
RE: SUGGESTION TO DETERMINE HYDRO TEST PRESSURE
RE: SUGGESTION TO DETERMINE HYDRO TEST PRESSURE
RE: SUGGESTION TO DETERMINE HYDRO TEST PRESSURE
Pipe: 10.75 O.D. x 3 mm w.t. (0.118")
ASTM A53 Gr B, Yield Stress = 35000 psi
Permits a Maximum Operating Pressure of 553 psig
IF it is tested to AT LEAST 692 psig for 4 hours.
MAOP is defined as Minimum Test Pressure / 1.25
so if you hold a minimum test pressure lower than 692,
you would have to divide the actual minimum test pressure by 1.25 to determine your actual MAOP.
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RE: SUGGESTION TO DETERMINE HYDRO TEST PRESSURE
Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada
RE: SUGGESTION TO DETERMINE HYDRO TEST PRESSURE
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