Brian,
This is your first posting on this website so let's see if we can help you with your question.
It would have helped if you had provided more information.
Information such as:
- Pipe size?
- Pipe wall thickness?
- The reason for adding a reinforcing pad to the pipe if there is no Branch?
- The reason for a reinforcing pad for a Shoe?
- Why pneumatic test a pipe that is not a service containment weld?
- Why don't you go ask someone in the Piping Department?
Welds to the out side of a piece of pipe that is not subject to the product under pressure or temperature but is only an external attachment does not need pneumatic testing or hydro testing.
Sometimes its possible to do all the right things and still get bad results
Can you tell me where you read this? "Welds to the out side of a piece of pipe that is not subject to the product under pressure or temperature but is only an external attachment does not need pneumatic testing or hydro testing."
The re-pad should include a minimum 1/4" diameter weep hole as shown in your picture for a couple reasons. One is to vent any trapped gases during welding and prevent the re-pad from becoming a "jacketed" vessel, and two is to show any indications of leakage. You can also perform a simple air and soap test at around 15 psi to check for any signs of leakage.
ASME B31.3 para 328.5.4.g states:
"Reinforcing pads and saddles shall have a good fit with the parts to which they are attached. A vent hole shall be provided at the side (not at the crotch) of any pad or saddle to reveal leakage in the weld between branch and run and to allow venting during welding and heat treatment. A pad or saddle may be made in more than one piece if joints between pieces have strength equivalent to pad or saddle parent metal, and if each piece has a vent hole."
Brian,
I don't remember reading it anywhere.
My comment is my own opinion based on my 64 years of training, experience and consulting.
That 64 years included many years in the Design office, two and a half years as the Engineering Manager in a Pipe Fab Shop and numerous field assignments at job sites during construction.
Sometimes its possible to do all the right things and still get bad results
I guess the question I would like clarification on is, what type of pneumatic test do you mean? Do you mean a simple 15 psi leak test of the welded attachment itself, or do you mean a full 1.1x design pressure pneumatic test? The latter would not make much sense to me.
I agree with pennpiper's comment "Welds to the out side of a piece of pipe that is not subject to the product under pressure or temperature but is only an external attachment does not need pneumatic testing or hydro testing." My answer was more about the 15 psi air and soap leak test, and after quickly glancing through the code again, I do not see anything stating that the 15 psi test is "required". It may just be a common practice to perform after fabrication.
just a simple 15psi pneumatic test is all i was asking for info on. This piping came pre-fabbed and now the client is wanting to know why the shop didn't perform a pneumatic test on the re-pads. I agree that they dont need it but was wondering if someone had anything in writing that i could present to them. i cant find it in any of the client specifications & I don't think they are to sure either.
My understanding is that the pneumatic test of the nozzle re-pad is usually performed for the pressure vessels (per ASME) and tanks (per API). For the pipe shoe re-pad on the piping system, it was part of the hydro testing of the whole pipe section, unless specified otherwise. It could be existed, but I don't see the specific pneumatic test as called out for the piping re-pad.
BrianPSJ,
When pneumatic testing (soap & bubble) is required it will clearly state in the applicable code or project specification that a threaded hole is required in the reinforcing pad.
An unthreaded hole is nothing more than a vent hole and does not require any testing.
I think it is unfair for you to be wasting time trying to find a reason to satisfy the client as to why no testing has been performed.
Sometimes it is better to politely ask the client why they think it needs testing - better to let them waste their time,
Cheers,
Shane
