PWHT of .337" M.W SA217 C5 ( P5B )
PWHT of .337" M.W SA217 C5 ( P5B )
(OP)
Hello,
We have a 4" SCH. 80 ( .337" M.W ) SA217 C5 Valve that we are going to weld to a piece of 4" 335 - P22. So it's a P5B to P5A weld. Our procedure calls for a minimum of 2 HOUR soak time on P5B Material - to give all of the martensite time to temper.
** My question is the ramp up time since it is so thin. I know B31.1 has a heating and cooling rate where as Section I simply says to bring it up "slowly "
0 - 600 no limit and then Above 600, heating and cooling shall not exceed 600/hour divided by one half the maximum thickness of material in inches at the weld.
So we'll say we have an 1/8" weld crown that would put at us at .337 + .125 = .462 divided by .5 = .231 ( approx. 1/4" ). So 1/4 of 600 degrees is about 150 degrees per hour ? Looking at around 4 1/2 hours to go from 600 degrees to 1300( our PWHT target temperature). Is this correct.
Thank you for your time
We have a 4" SCH. 80 ( .337" M.W ) SA217 C5 Valve that we are going to weld to a piece of 4" 335 - P22. So it's a P5B to P5A weld. Our procedure calls for a minimum of 2 HOUR soak time on P5B Material - to give all of the martensite time to temper.
** My question is the ramp up time since it is so thin. I know B31.1 has a heating and cooling rate where as Section I simply says to bring it up "slowly "
0 - 600 no limit and then Above 600, heating and cooling shall not exceed 600/hour divided by one half the maximum thickness of material in inches at the weld.
So we'll say we have an 1/8" weld crown that would put at us at .337 + .125 = .462 divided by .5 = .231 ( approx. 1/4" ). So 1/4 of 600 degrees is about 150 degrees per hour ? Looking at around 4 1/2 hours to go from 600 degrees to 1300( our PWHT target temperature). Is this correct.
Thank you for your time





RE: PWHT of .337" M.W SA217 C5 ( P5B )
Second, using B31.1, the rate shall be no greater than 600 deg F/hr or 600 deg F/ 1/2 the thickness. In your case, the 600 deg F/ .5 x .337 > 600 deg F/ hr. Therefore, you are bound by 600 deg F/hr rate for this thickness.
The time for PWHT is based on Table 132 in B31.1 where the time is 1 hr/inch of thickness. Under 2", this applies resulting in a time of 1 hr/inch * .337" = 1/2 hour at PWHT temperature.
RE: PWHT of .337" M.W SA217 C5 ( P5B )
As far as ASME Sec. 1 is concerned, what does "slowly" mean to you ? Should you just go with B31.1's requirements ?
Thanks again.
RE: PWHT of .337" M.W SA217 C5 ( P5B )
Appendix A. Under 2" thickness, either 400-600 deg F/hr heat-up or cool down rate is slow enough to avoid thermal stresses which can result in distortion or cracking.