ASTM/ASME SA-790 lop whole length.

By Lawrence (*****)

Date 03-05-2010 15:00

I can't help at all (sorry)

But I would really like to see an etched cross section of the offending pipe if you could get one!

By Mikeqc1 (****)

Date 03-09-2010 21:15

I have the pipe, i think im going to flatten it for my own infomation.
i do have an xray.
Im going to take the wall thk min violation route, unless someone knows if ASME excludes the weld area from that requirment.
Any1?

By js55

Date 03-05-2010 16:06

Mike,
The answers to probably all of these material questions you've been asking are either found in the manufacturing spec referenced or they don't exist.
For example, SA-790 has to reference a weld acceptabilty criteria somewhere.
The problem is the material manufacturers are the very guys that write the material specifications and they have a tendency to not be too tough on themselves. You might find the criteria more lenient than you would assume.
In that case you have to impose additional or more robust criteria, and will of course pay more for it, and it will generally take more time for delivery.
Another answer is to contact a material supplier you have that is not the one that supplied the material in question. They will be more likely to give you an honest answer.

By Mikeqc1 (****)

Date 03-05-2010 18:29

this was the response from the supplier
The pictures are exactly what we needed to determine what the situation was on this pipe. Please note that based on the picture, this is IP (incomplete penetration) where the OD/ID welds didn’t quite meet all the way. THIS IS NOT A CRACK. The only way to catch something like this is with xray, ultrasonic testing or other NDE means that are NOT required by standard ASTM/ASME SA790. ASME has a joint factor of anywhere from I believe .70 to .85 for a double welded product like this, unless xray is required. 100% xray would take a welded product to 1.0 joint factor. Dye penetrant testing is also not a requirement of ASTM/ASME SA-790.

Basically, while we wish every piece of pipe we produce would pass xray, there is no way to guarantee that unless xray is ordered. This pipe was produced and tested in accordance with ASTM/ASME SA-790.

By Mikeqc1 (****)

Date 03-05-2010 22:27

we had to buy new pipe.............

they sent another pipe ..... now this pipe is marked sa-312 and sa-790
how does that work?
Im not happy about this pipe the supplier sent a reply from the manufacturer.
He says The pipe is not x-ray quality and has been tested to sa-790 .
So for a pipe with a MIN wall thickness of .322 1/8 of that can be unfused and its acceptable?
i could not sleep at nite with that pipe on a vessel of any kind.
this indication Bled like a Stuck Pig.
we took an xray and its along the whole length, DARK AS DARK CAN BE.
WOULD ANY OF YOU ALL USE IT?

By 803056

Date 03-11-2010 23:14 Edited 03-11-2010 23:21

Maybe for a handrail.

Sound like a case of "know your specification and know what you are buying.” In the same vein, make sure the purchase order is properly written and it contains all the pertinent information.

It never fails to amaze me that people ordering material have very limited insight as to what they are purchasing. It is as if they go to the car dealership and simply say, “Give me a car that is shiny and new.” Then they get miffed because the vehicle delivered is a four banger with three tires, each a different size, and the driver’s door is missing.

If you don’t ask for “it” in the purchase order, don’t expect “it” upon delivery.

Al