ASME hydraulic test pressures
ASME hydraulic test pressures
(OP)
Good morning to you all.
I'm working on a filter that has to be built according to ASME code. We are from Italy and we are used to PED Code, so we are having a little trouble.
We usually make two set of calculations; one for Design conditions and the other one for Hydraulic test conditions. PED code, however, allows us to use an higher allowable stress for alloys under hydraulic test conditions.
My questions are:
1) Are hydraulic test calculations mandatory for ASME code vessels?
2) If 1) is "yes", do we need to make Hydraulic test calculations with standard allowable stresses or there is some variations? (I'm considering SA 240 TP 316 H.S. material, and design temperature will be 120°C while Hydraulic Test temperature will be 20°C- so, if I understand correctly, allowable stresses should be the same..)
Any answer would be greatly appreciated! We are not willing to avoid code mandatory documentation, but we are not willing to design a vessel for a far greater (1,66x!) pressure if we are allowed not to.
I'm working on a filter that has to be built according to ASME code. We are from Italy and we are used to PED Code, so we are having a little trouble.
We usually make two set of calculations; one for Design conditions and the other one for Hydraulic test conditions. PED code, however, allows us to use an higher allowable stress for alloys under hydraulic test conditions.
My questions are:
1) Are hydraulic test calculations mandatory for ASME code vessels?
2) If 1) is "yes", do we need to make Hydraulic test calculations with standard allowable stresses or there is some variations? (I'm considering SA 240 TP 316 H.S. material, and design temperature will be 120°C while Hydraulic Test temperature will be 20°C- so, if I understand correctly, allowable stresses should be the same..)
Any answer would be greatly appreciated! We are not willing to avoid code mandatory documentation, but we are not willing to design a vessel for a far greater (1,66x!) pressure if we are allowed not to.
Che Dio ce la mandi buona, o almeno ce la mandi- Massimiliano Eusebi





RE: ASME hydraulic test pressures
ASME Section VIII Division 2 specifies allowable stresses at test in paragraph AD-151.1 as below, which gets a bit tricky. Pm is general primary membrane and Pb is primary bending
(a) Pm <= 0.9 * Sy
(b1) Pm+Pb <= 1.35*Sy for Pm <= 2/3*Sy
(b2) Pm+Pb <= 2.2*Sy-1.5*Pm for 2/3*Sy < Pm <= 0.8*Sy
RE: ASME hydraulic test pressures
I am not certain where you get the factor 1.66 times design pressure (or MAWP). Is this from PED?
Current ASME Section VIII Div 1 requires testing at 1.3 x MAWP (or design pressure) per UG-99(b). Division 2 has factor 1.25.
RE: ASME hydraulic test pressures
HTP = DP * 1,3 * SHT/SD
Where:
HTP: hydraulic test pressure
DP: design pressure
SHT: allowable stresses at hydraulic test temperature
SD: allowable stresses at design conditions
Even if we have ASME SA 240 TP 316L as main vessel material, there is a very important flange made out of SA 193 Gr. B8- and this material DO change allowable stresses at 20°C and at 120°C. Hence the 1,66 multiplier.
Thanks a lot, Tombarsh. I'll try to work out on what you said to me.
Che Dio ce la mandi buona, o almeno ce la mandi- Massimiliano Eusebi
RE: ASME hydraulic test pressures
Che Dio ce la mandi buona, o almeno ce la mandi- Massimiliano Eusebi