Controlling Pipe Dimensional Quality
Controlling Pipe Dimensional Quality
(OP)
We use API5L Gr.B and ASTM A106 Gr.B piping. Recently we have had quality issues; one batch of pipe had ends that were not cut square; another batch had eccentric OD and ID resulting in wall thickness below the minimum in one position. Dimensional issues make fitting more difficult and can result in additional costs.
It would seem that ordering to the standards alone is not sufficient to control the dimensional tolerances on the pipe.
We are about to order some material for an expansion project with approx 1600m of 12" Sch 80 pipe and do not want to be hit with quality issues.
Does anyone have any advice over how I can better control the material quality? Also how to capture it at the bid stage?
Many thanks
It would seem that ordering to the standards alone is not sufficient to control the dimensional tolerances on the pipe.
We are about to order some material for an expansion project with approx 1600m of 12" Sch 80 pipe and do not want to be hit with quality issues.
Does anyone have any advice over how I can better control the material quality? Also how to capture it at the bid stage?
Many thanks





RE: Controlling Pipe Dimensional Quality
Start by knowing exactly where the pipe is coming from, and what the track record of the mill or supplier is.
-TJ Orlowski
RE: Controlling Pipe Dimensional Quality
One of the biggest problems we encounter is out of round on the thinner sections. We are a little more lenient in this respect as we have the tools to reform, align, and prep the pipe sections. If push come to shove you can accommodate nearly anything except thin sections.
People like Dearman make all types of tools to get pipe prepared for welding. If you look at the number of tool available for aligning and fitting pipe should tell one that pipe doesn't fit the classic description of pipe any more.
http://www.mathey.com/products/pipealignment.shtml
RE: Controlling Pipe Dimensional Quality
RE: Controlling Pipe Dimensional Quality
For large purchases is was not uncommon to provide full shift inspection at the mill - but that was before "buy cheapest" reigned supreme and vendor surveillance became anethma.
RE: Controlling Pipe Dimensional Quality
Standards are not a complete recipe for manufacturing or purchasing pipe. Qualified personnel needed to ensure that pipes and pipelines performed as intended.
What's the response from the vendor/manufacturer? You should ask for corrective and preventive actions...
RE: Controlling Pipe Dimensional Quality
I've work on new pipe problems where the long seam wasn't weld, even though a UT was list as part of the inspection at the mill. I've had CS and tube that looked pretty but fell of spec on chemistry and or physical properties.
There are two domestic producers of pipe that are not on our bid list due to ongoing problems.
RE: Controlling Pipe Dimensional Quality
We do not buy direct from the mills and we don't have the resources to inspect at the mill or audit the mills ahead of production. I would agree to audit the mill and inspect the product would be the way to go if we could.
Rejecting material when it is delivered is all well and good, but it causes a large project delay and trouble sorting it out with the supplier. In essence, it becomes my problem more than the suppliers.
The buyer will want to go to the lowest bidder and it can mean the worst quality. I want to put something in place at the bid stage that will level the playing field so that we only get prices from "good" mills and we highlight our concerns over dimensonal tolerance.
Perhaps you could consider the following points?
1. Are there any accreditations that might be worth looking for e.g. API?
2. Any countries to avoid?
3. Is it of value to get 3rd party inspector to check the mill (EN 10204 Type 3.2 Certification)
4. Are there any useful clauses I could add when we go out to bid?
Thanks again
RE: Controlling Pipe Dimensional Quality
it should say something that if pipe is returned due to not meeting spec and a delay in the project results then the supplier shall be liable for $XXX or any costs resulting from the delay.
that should weed out any "suspect" suppliers.
good luck.
RE: Controlling Pipe Dimensional Quality
*Yes, metallurgical testing is necessaary. API, and thus OSHA, require Positive Material Identification - PMI. Since it is a proven fact that Malasian, Chinese, Bulgarian, etc 3rd-World materials often have Material Certs that do not match the delivered items, you are required to verify the chemistry of each Heat No. of cheap stuff. A Niton-type XRF X-ray fluorescent 'gun' will cost you about $3-400/day [with a technician] to do the testing. Or you can buy your own XRF 'gun' for about $35K. Makes cheap materials moderatly expensive. Just buy from reputable, 1st-world manufacturers.
RE: Controlling Pipe Dimensional Quality
Vendor pre-qualification and bidder list should be considered at first stage. After that you should have system for evaluation and record their performance...
From my experience, 3rd party may be helpful (or not). You have to focus on how to select the 3rd party inspector and review their time sheets/reports...
RE: Controlling Pipe Dimensional Quality
Again, the hidden costs and risks of buying "certified" material from known liars is HUGE. Be very careful with 3rd-world items. Some meet spec, some don't.
RE: Controlling Pipe Dimensional Quality
If your not in a position to help direct your Purchasing Contracts folks and Quality people, you just have to make the right decision upon receipt of the material.
" There is no Shortcut to anyplace worth going "
RE: Controlling Pipe Dimensional Quality
Does anyone have any history or lessons learned in regards to ASME qualified suppliers of material?
At present we rely solely on CMTR's and the ASME suppliers QA that the material received meets the specifications. We do minimal dimensional checks on the ends of the product.
We are considering the purchase a PMI type instrument. I do not remember the name but it is less expensive then the XRF Duwe6 makes note of. I seem to recall it is in $10-15000 range.
At this time management will be only permiting it's use if the material is suspected to be counterfeit.
Some of our US suppliers of ASME material supply material from Chinese Mills. The AMSE suppliers provide mech and chem reports of the tests they had performed on their behalf.
We also procure ASTM, non nuclear pressure boundary on non pressure boundary materials and typically only request a Certificate of Compliance for non pressure boundary materials.
Are there additional testing or concerns that should be considered when receiving material from ASME and non ASME suppliers?
Are there any recommended practices or standards on the verification of purchased materials out there?
RE: Controlling Pipe Dimensional Quality
My answer was to explain to our Buyer the costs of me performing Positive Material Identification - PMI and full dimensional inspx on our Receiving dock. I think she is convinced to purchase from a higher-priced supplier that does the PMI and dimensional checks at his distribution warehouse. There probably are others, but the only supplier I know of is Pipe Products.
RE: Controlling Pipe Dimensional Quality
Yes it helps, thanks.Thanks it helps.
Luckily, we have not had many field rejects that I am aware of because of dim. tolerance or chemical non conformances.
It will probably take a significant event and or a strong industry push to change how we do business. It is the counterfiet concerns in our industry that is driving us to get a metal analyzer. If I had some documented references on recommended practices or guidelines I would forward to managment for their consideration.
I do not believe that the analyers we are considering can provide Cobalt either, which is a critical requirement in some our applications.
Will sufficient assurnace be provided by an instrument that cannot provide such a critical element as carbon?
If a company has supplied material that is certified as meeting ASTM or ASME and is found to be non conforming or fraudulentis there an entity that it should be reported to? Is there a registry of information on fraudlent material and suppliers?
RE: Controlling Pipe Dimensional Quality
I have decided to try the following approach in our bid request package:
1. Western European mills only unless the supplier carries out their own independent verification – chemistry, mechanical and dimensional tests
2. We will detail our critical dimensional tolerancing we are concerned about and that will reject if not compliant
3. We will do a technical inspection on the deliveries including dimensional checks and material certificate reviews – this will be done before the truck unloads. We will tell the supplier this will be happening in our bid request package.
4. We will request the option to conduct an audit/inspection the mill. I am doubtful I would be authorised to go, but it should indicate that we mean business.
5. I hope to get some financial penalty written in by the purchasing department for any rejected materials.
I hope that the above measures will indicate that we are serious and don't want the cheapest / poorest quality materials.
Ideally it will level the playing field for all the bidders and we can be more confident that the materials on order will turn out to be what we want when they arrive.
RE: Controlling Pipe Dimensional Quality
is way off base. The cost of the XRF instrument we are considering is line with with what Duwe6 states.