ASME Sect 1 PW.39 P4 materials non pressure parts to pressure parts

[rmillercwi]

Asme sect 1 pressure vessel. Unit has been in service for several years.

Simple bracket made out of 1/4" thk CS plate welded directly to the O.D. of a 10" sch 120 1.25cr pipe. 3/8" fillet weld. 10" sch 120 pipe is .844 thk. (above 5/8")

ASME Sect 1 for P4 materials. I read this joint configuration to be exempt from PWHT provided a 250 f preheat is applied as long as the fillet weld is under 1/2".


The contractor is insistent on performing PWHT based on evaluation of current code verbiage based on the thickness of the basemetal beyond 5/8" thk. and thus the exemption is not applicable. In my opinion, PWHT is not required here.

 

[metengr]

Section I is not a pressure vessel code, Section VIII, Div 1 is.

The contractor is insistent on performing PWHT based on evaluation of current code verbiage based on the thickness of the base metal beyond 5/8" thk. and thus the exemption is not applicable.

Contractor is correct, PWHT is required. See the information below from Section I.

Second, assuming it is Section I, review Table PW-39-3 of the 2013 edition, see the excerpts below. Note 3 would apply.

(1) for circumferential butt welds in pressure parts with all the following conditions:
(a) a nominal base metal thickness of 5/8 in. (16 mm) or less at the weld
(b) a maximum specified carbon content (SA material specification carbon content, except when further limited by the Purchaser to
a value within the specification limits) of not more than 0.15%

(3) for pipe and tube materials meeting the requirements of (1)(a) and (1)(b) above and having fillet welds attaching nonpressure
parts to them, provided the fillet weld has a throat thickness of 1/2 in. (13 mm) or less and the material is preheated to 250°F
(120°C) minimum; or combination groove and fillet welds attaching nonpressure parts to pressure parts, with a weld thickness of
1/2 in. (13 mm) or less, provided the material is preheated to a minimum of 250°F (120°C); or heat‐absorbing surfaces and
non‐load‐carrying studs attached to them, provided the material is preheated to 250°F (120°C) minimum. A lower preheating temperature
may be used, provided specifically controlled procedures necessary to produce sound joints are used. Such procedures shall include
but shall not be limited to the following:
(a) the throat thickness of fillet welds shall be 1/2 in. (13 mm) or less
(b) the maximum continuous length of fillet welds shall be not over 4 in. (100 mm)
(c) electrodes or filler metal shall be dry and shall provide a low-hydrogen weld deposit. Chromium-molybdenum filler metals shall
have a maximum specified chromium content of not more than 2.50% and a maximum specified carbon content of not more than 0.05%
(d) the thickness of the test plate used in making the welding procedure qualification of Section IX shall not be less than that of the
material to be welded.