RF pad pneumatic test

Ajimon · **Joined:** Wed Oct 07, 2009 10:53 am **Posts:** 40

Dear all,
Is pneumatic test for Nozzle RF pads mandatory for ASME SEC VIII Div 1 vessels
As per UG 37 (g) RF shall have tell tale hole which may be tapped for preliminary pneumatic test

BR

A VP

Javed Nasir · **Posted:** Mon Mar 07, 2011 9:42 am

Pneumatic Test of RF pads is not a mandatory requirement of UG-37(g) and not elsewhere mandated in the code (VIII-1) as far as I know.
".......may be tapped for preliminary pneumatic test......" "may be" is advisory language not mandatory language.

Rathnam · **Joined:** Fri Jul 09, 2010 7:57 am **Posts:** 79

Pad test is required . See UG-37(h) .
"Every segment shall be tested as per UG-37(g)".
A careful reading suggests that Pad test is mandatory .
Optional is a)The hole may be tapped or not
b)The hole may be plugged or not .
Also see UW-46 which refers to the test.

Pad is tested for leaks in the inside weld . Note that no pressure is prescribed . The intent is to check for leaks if any . Any intentional pressure can damage the vessel .

As for practice , Pad test is carried out & shops do not skip this test. A leak in the Pad weld is difficult to find during Hydro Test as the pad masks the weld. Hence the need for this check .Also the compressed air hose is held by hand near the hole to avoid any pressure buildup . We can't be more careful , can we ? .

A inspection report is also necessary as evidence .

Javed Nasir · **Posted:** Mon Mar 21, 2011 7:09 pm

Rathnam,

I do agree with all what you said. Thank you for my correction.

Gonzaga · **Joined:** Sat Dec 15, 2001 1:00 am **Posts:** 657

Ajimon wrote:

Dear all,
Is pneumatic test for Nozzle RF pads mandatory for ASME SEC VIII Div 1 vessels
As per UG 37 (g) RF shall have tell tale hole which may be tapped for preliminary pneumatic test

BR

A VP

No. It is not mandatory. And in certain circumstancies it is impossible e.g. when there is no access inside the vessel and the nozzle is too small to make the test through it from the outside.
mauro

Rathnam · **Joined:** Fri Jul 09, 2010 7:57 am **Posts:** 79

I agree that for small vessels there is no access to inside.
In such cases Pad Test is carried out before closing the vessel .
Along with Pad Test , inside inspection of the vessel is also carried out (see UG - 97(a) .

sooeey2u · **Posted:** Fri Apr 08, 2011 4:35 pm

It is not mandatory. We have had Client requests but our AI has never required RF Pads to be tested.

RF pad pneumatic test

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