UCI-99 (Standard Hydrostatic Test)

Cast iron pressure vessels shall be hydrostatically tested by the method prescribed in UG-99 except that the test pressure shall be two times the maximum allowable working pressure to be marked on the vessel for maximum allowable working pressure greater than 30 psi (200 kPa) and 2 1/2 times the maximum allowable working pressure but not to exceed 60 psi (400 kPa) for maximum allowable working pressure under 30 psi (200 kPa)

I could not understand / apprehend the code language.

Can anyone explain "Range wise" what will be the Hydro Test pressure (2 times or 2 1/2 times)?

MAWP (0 - 30 psi) - Hydro Test Pressure 2 times the MAWP?

MAWP (30 - 60 psi) - Hydro Test Pressure 2 1/2 times the MAWP?

and for MAWP (Greater than 60 psi) what will be the Hydro Test Pressure?

Thanks

Hello Mac,
I read it this way:
For MAWP > 200 kPa => PT = 2 x MAWP
For MAWP < 200 kPa => PT = smaller of {2,5 x MAWP; 400 kPa}

Michael

I also read the same way as Michael does.

Dear Michael,

if the MAWP=200 Kpa then what would be the test pressure?
Code says 2 times if MAWP>200 KPa, smaller of (2.5 times or 400 Kpa) for MAWP<200 Kpa,
but what about if MAWP=200?

what I interpret is, for MAWP=200 Kpa, TP = Smaller of (2.5 Times, 400 Kpa), Please comment.

_________________
Thanks & Regards,
Nasir
Welding Engineer
DESCON Engineering Limited.
Lahore, Pakistan.
Mobile # 0092-336-4145402

Hello Javed,
it´s the same for both cases, since 2 times 200 kPa is 400 kPa, and the smaller of (2.5 times or 400 Kpa) is 400 kPa too. Therefore the correct pressure is 400 kPa. I was confused about the same issue when I read it the first time.
Michael

Michael,

Thank you very much for your response.
I fully agree with you.
I just put the question in a hurry without reading carefully the above matter. Thank you once again.

_________________
Thanks & Regards,
Nasir
Welding Engineer
DESCON Engineering Limited.
Lahore, Pakistan.
Mobile # 0092-336-4145402