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API 6A 21st edition

API 6A 21st edition

API 6A 21st edition


We have placed the order for Wellhead equipment with API monogram (API 6A, 20th edition) in Oct 2019. Now, OEM has come up with clarification that equipment’s manufactured after Nov. 2019 will not be monogrammed as new API 6A 21st edition is in place. They are saying that there is a difference in raw material qualification (QTC) w.r.t. 20th edition and if we still need the monogram, then, it will have a cost impact.
Can you please tell me what the difference between two editions is? How will it effect on cost? What is QTC and ER as defined in API 6A?

RE: API 6A 21st edition

The differences are complicated and depend on the PSL, product/component type, and material size at heat treat. The OEM should be able to provide you with more detail on the differences (or you could read the relevant sections of both editions yourself). It could require the supplier to source new material (as opposed to material they have in stock which met API 6A 20th Edition), which could have a significant effect on cost and delivery time. Ask the supplier if you want a more precise answer.
QTC = Qualification Test Coupon (coupon used for mechanical and charpy testing; either a separately forged part, a prolongation, or a sacrificial part)
ER = Equivalent Round (estimate of equivalent round section size for the purpose of heat treatment)

RE: API 6A 21st edition

Can you check the dates??

"placed the order for Wellhead equipment with API monogram (API 6A, 20th edition) in Oct 2019".

I've heard of forward planning, but this is a bit far fetched.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: API 6A 21st edition

API requires that a product being manufactured, regardless of the order date, be to the current edition at the time of shipping in order to receive a monogram. They should have informed you when you requited a quote. But I can say many companies will have this same issue.

RE: API 6A 21st edition

How important is it to have the monogram? Would a 3.1, or 3.2, inspection document serve in this case?

Steve Jones
Corrosion Management Consultant


All answers are personal opinions only and are in no way connected with any employer.

RE: API 6A 21st edition

Metboss the requirement is that if an API 6A license holder would ship an order after November 1 it must comply to the 21st edition. There have been various changes to the standard, but with respect to cost impact the two most impactful have been the changes to QTC requirements and bolting requirements. The largest change to API's QTC requirements is that for PSL 3 or greater 75K bodies that would be greater than 1000 lb during heat treat the QTC must have an ER>= the part with a maximum of 10 in unless specified. Previously there was a maximum ER requirement of 5in. So a new QTC now needs to be produced and mechanically tested in order to certify mechanicals to 6A 21st edition. Depending on what stage of production the manufacturer of this wellhead is in, new body material may need to be procured. If you do not need the monogram you can accept the COC to the 20th edition and receive your order as planned.

As to Steve's question about a 3.1 or 3.1 certificate; the issue at hand here is the size of the QTC where the mechanical properties listed on a 3.1/3.2 certificate are taken from. Unless there are sampling requirements in 3.1/3.2 that would meet or exceed the API 6A requirement getting the certificate is not likely to change the monogram status of the wellhead.

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