EF-welded pipe · Lower-temperature & atmospheric service
An A671 designation is not one requirement — it is a string of them. The base plate the pipe is assembled from, the class it is placed under, the temperature service it fits, the welding it carries and the examination it is evidenced by. Build that string in the order the standard does, and the EF-welded offer you are comparing stops being a single line item and starts being a deliverable you can actually check.
Price on request. A specified welding process is not a pressure-code approval — design and construction-code acceptance stay with your project, and the class is confirmed against the requirement you state.
Base plate
The plate specification the pipe is assembled from.
Class
The ordered condition — treatment, extras and tests.
Service
Lower-temperature and atmospheric, not A672's scope.
Weld & NDT
The welding and examination the order must evidence.
A671 order builder
An A671 pipe is ordered as a string, not a single word, and every offer you compare should be read against the same five segments. Fill them in as far as your project allows; the builder reports what is set and what is still open — it does not choose a class for you or tell you the pipe suits your service, because those are engineering decisions.
Base plate specification
Which base plate specification is the pipe assembled from?
A671 is built on an underlying plate specification. Name it, or the base material is left to whoever supplies the pipe.
Class
Which class is the order placed against?
The class carries the ordered condition — heat treatment, supplementary requirements and testing. Unstated, those provisions are unfixed.
Temperature service
Confirm the pipe is for lower-temperature or atmospheric service, not moderate-temperature pressure duty.
A671 is written for lower-temperature and atmospheric service. Moderate-temperature pressure service is A672's scope, a separate standard.
Welding process
Is the welding process and its qualification requirement named?
The welded joint is part of the deliverable. Unnamed, the weld procedure and its acceptance are left to assumption.
NDT evidence
Is the non-destructive examination scope your project expects agreed on the order?
The NDT an order carries is not implied by the class. Left open, the certificate may not demonstrate what your project expects.
5 of 5 segments still open. Each one is a requirement the order should carry rather than a supplier's assumption — an unset segment is where an EF-welded enquiry most often goes wrong.
Take it to the RFQOrder string
The designation as you have built it. Copy it into a specification review, a comparison sheet or the enquiry below.
ASTM A671 steel pipe — order string Base plate: — not stated — Class: — not stated — Service: — not stated — Welding: — not stated — NDT: — not stated — 5 of 5 segments still unset — fix these before the pipe is ordered against A671. Supplier: Noor Deira Steel Trading L.L.C. — sales@noordeirasteel.ae — +971 56 398 0860 Governing edition, construction code and acceptance criteria to be confirmed at quotation.
The builder assembles the requirement — it does not approve it. Which class your order needs is a decision the specification and your project's requirements together settle; whether the welded joint is acceptable is a construction-code call owned by your fabricator and inspector. Use the builder to make sure every segment has an owner and a stated value before the pipe is ordered.
What A671 governs
The specification is written as a base plate plus a class, and that two-part structure is the whole point: the plate settles the base material, the class settles everything the order adds on top. Miss the structure and the offer looks complete when it is not.
Inside the specification
Outside it — and often assumed
Why the two-part structure matters to a buyer
Other pipe standards carry their requirement in the grade name; A671 carries it in a name plus a class. The base plate says what the pipe is made of, and the class says what was done to it and what was checked. That means two offers can both read "A671" and still not describe the same pipe — same plate, different class, different deliverable. Reading the designation as one word is how a buyer ends up comparing offers that never described the same thing.
It also matters because the welded construction is the product, not a by-product. An electric-fusion-welded pipe is assembled from plate, so the seam, its procedure and the examination of that seam are central to the deliverable rather than an incidental detail. That is what makes the class and the examination segments of the order string worth fixing explicitly — and it is exactly the ground on which a large-diameter EF-welded option gets accepted or refused.
We publish no allowable stress, wall tolerance, treatment temperature or service limit for this standard. Each follows the governing edition read with your design basis, and is confirmed against the requirement you state.
Where A671 stops
These two standards are confused constantly, because both describe electric-fusion-welded pipe and the difference is not in the weld. It is in the temperature service the pipe is written for. Getting that wrong is a specification error that follows the pipe all the way to site.
A671 — the service this page covers
A671 is written for lower-temperature and atmospheric service. It is the electric-fusion-welded specification a buyer reaches for when the duty is at the cooler end of the range, or when the pipe is not carrying a moderate-temperature pressure service at all. If your design basis sits here, the page you are reading describes the standard you need.
A672 — a different standard, a different scope
A672 is the moderate-temperature pressure-service specification for the same electric-fusion-welded family. It is not a variant of A671 and it is not interchangeable with it: the temperature service it is written for is different, so a pipe that satisfies one does not automatically satisfy the other. Which one applies follows from your design temperature and duty, and that call belongs to your design authority, not to a supplier's catalogue.
Choosing the right family — and the adjacent standards worth checking
When the pipe is seamless rather than welded, or the service sits in the carbon-steel range rather than the EF-welded one, the standard changes entirely and so does the acceptance basis. Those are the comparisons that catch a wrong specification before it is ordered — a seamless family, and a carbon plate-based family, both look superficially similar on a requisition and are neither of them A671.
No equivalence between A671 and A672 is implied anywhere on this page, and none should be read into a quotation. Confirm the governing standard with your design authority before the pipe is ordered.
Welding and examination evidence
On an EF-welded pipe the joint is the product, so the welding and the examination of it are the two fields a buyer must not leave to chance. The distinction that matters is between the provisions the specification carries and the supplementary requirements your project adds on top — one is a floor, the other is your actual requirement.
The welding the pipe is made with
The welding process is named on the order, and the procedure behind it belongs to the fabricating works. A named process is a starting point — it is not the same as a qualified procedure accepted for your joint.
The examination the order carries
Non-destructive examination is not implied by the class alone. Whether the seam is examined, and how, is a scope the order should state so the certificate demonstrates what your project expects to receive.
The evidence it arrives with
The records that tie the delivered pipe to its plate, its welds and its examination are agreed when the order is placed. On a large-diameter EF-welded line these records are often what decides acceptance at site.
A reasonable fit when
Revisit the basis when
On an EF-welded pipe the welding and the examination are not paperwork trailing behind the product — they are part of what you are buying. Naming them on the order is how the offer you accept, and the certificate that arrives with it, describe the same pipe. If the product form itself is still open, start from the steel pipe supply reference — the welding route and its evidence follow from the form you choose, not the other way round.
GCC markets
Destination changes the commercial and documentary side of the order, not the acceptance basis. Choose the market to see what each destination expects before the consignment is released.
The hub for the other pipe specifications. If the standard itself is still being chosen, settle it against your temperature service before the pipe is ordered — the ordering discipline is the same, but the acceptance criteria are not.
Project coordination and release documents.
Confirm the base plate, class, temperature service, welding and NDT scope against the project requirement, then plan release to site, fabricator or stockist.
Specification alignment and import papers.
State the class, governing edition, construction code and ordered examination alongside the delivery base so the offer matches the requirement.
Requirement and delivery window.
Confirm dimensions, wall thickness, quantity and delivery window so the documentation plan stays aligned to the order.
Delivery basis and documentation.
Give the delivery point and Incoterm so the certificate and release paperwork can be arranged against the order.
Contract terms and certificates.
Settle the record set and the plate traceability before quotation — it is the field most often left open on an EF-welded enquiry.
Energy and process supply.
Provide the destination, the required records and a delivery date so the offer can be fixed against your inputs.
These market pages are procurement destinations, not a claim of premises in each country. Supply is coordinated from Dubai and delivered against the destination and delivery date you state.
Compare and verify
An EF-welded standard is frequently specified where a seamless or carbon one was meant, and the neighbouring references carry the decision either way. These are the pages worth checking — together with the ones that take the standard-level decision down to a base material.
The hub for the other pipe specifications, so you can compare scope before committing to one.
Useful when the standard itself is still being chosen.
How ASTM steel designations are organised — the wider reference the base plate sits within.
Start here when the plate designation is still open.
The product form to check when the requirement is tubing rather than pipe — a different dimensional basis.
Useful when pipe and tubing could be confused.
A seamless carbon specification, often specified where an EF-welded pipe was actually intended.
Check whether your product form is welded or seamless.
Comparing across a standard family
A welded-pipe designation is not an interchangeable part for a seamless one, and within the welded family the service scope is not a quality tier — A671 and A672 are two scopes, not two grades of the same thing. Moving between families changes the product form, the acceptance basis and the records the pipe arrives with, so it has to be re-confirmed against your design basis rather than carried across from a designation on an old requisition.
Where the requirement is a steel tube rather than a pipe, check the product form first — the dimensional and standard basis changes with it, and so does what the record has to demonstrate.
Read the governing standard
The base plate references, the classes the specification lists and the marking requirements all sit inside the standard. Read it alongside your project specification and your construction code rather than relying on the designation alone — the three documents answer different questions, and the standard only answers its own.
Destination matters commercially on a large-diameter order — the UAE market page sets out how project coordination and release documents are handled locally, which is worth reading before you fix the delivery basis.
From order string to offer
The builder settles which decisions belong to the material order, the welding and the design code. This is the sequence that turns that split into a comparable offer, and the point at which each input is actually used.
Temperature service established
Design authority
The duty is placed in lower-temperature or atmospheric service — the scope A671 is written for.
If the duty is moderate-temperature pressure service, A672 applies instead.
Base plate named
Specification author
The base plate specification the pipe is assembled from is stated on the requirement.
Left open, the base material becomes whoever supplies the pipe's choice.
Class fixed
Buyer and commercial desk
The class is named, with the heat treatment and supplementary requirements it assembles.
The class carries the ordered condition — unstated, those provisions are unfixed.
Welding scope briefed
Fabricator
The welding process is named, and the procedure behind it is planned for the joint.
A named process is not a procedure qualified for your joint.
NDT and records agreed
Project team
The examination scope and the record set are written onto the order before it is placed.
An assumed examination scope surfaces as a gap in the certificate at goods-in.
Offer with commercial terms
Commercial desk
Availability, price, quantity and delivery confirmed on request.
Commercial variables stay open until you supply them.
Send the completed order string and the desk comes back against your requirement rather than a standard package. Reachable Monday to Saturday, 8.00 AM to 6.00 PM Gulf time.
Request a QuoteStraight answers
These are the ones the desk fields most often from large-diameter pipe buyers, answered the way they are answered there — including the parts that make the process slower.
No, and this is the assumption that costs the most on an EF-welded enquiry. A671 is a base plate plus a class, and the class is where the ordered condition lives — the heat treatment, the supplementary requirements and the testing the pipe carries. Two offers can both read A671 and describe different pipes, because the class differs. When you compare quotations, compare the full designation, not the standard's name. If an offer does not state the class, the class has not been fixed, and the deliverable is still open.
No. They are two specifications written for two different temperature services, and the shared welding process is exactly why they get confused. A671 covers lower-temperature and atmospheric service; A672 covers moderate-temperature pressure service. The choice follows from your design temperature and duty, and it belongs to your design authority — not to what a supplier happens to have. If your basis names one and an offer presents the other, that is not a substitution to accept quietly. We quote the standard your specification names, and we say so when it is the other one.
It is not. Specifying a welding process in a material standard is not the same as having a pressure design or an accepted joint. Pressure design, wall thickness for the duty and the acceptance of the welded joint under your construction code sit with your project, ASME or equivalent. A pipe can fully satisfy A671 and the system still has to pass its own design review, and the joint still has to be accepted. Treating the material standard as a design approval is the error this page is built to head off.
There is no single answer we would hand you, because the examination an order carries is assembled from the standard's provisions plus the supplementary requirements your project adds — and both are confirmed against what the order states, not assumed from the standard's name. That is why the builder asks you to name the NDT scope rather than reading one off a table. Tell us what your project expects the certificate to demonstrate, and the desk confirms the scope against it.
That is a materials decision, and we will not answer it with a plate recommendation from a supply page. The base plate the pipe is assembled from is a design and materials choice that follows from your service, your design basis and the properties your project relies on. What we can do is supply the pipe built on the plate your specification names, under the class your order states, with the records it requires. The selection is yours; the supply is ours.
We do not publish stock positions on this page, because a figure written here would be stale by the time it mattered, and availability varies with base plate, class, diameter, wall thickness and examination scope. It is confirmed against your stated basis, quantity and required date when the enquiry reaches the desk. That is the honest sequence — the answer you plan around is the one given for your order.
Frequently asked questions
Five questions large-diameter pipe buyers raise most often, answered without deferring the technical position to the quotation stage.
The class is the part of the designation that carries the ordered condition — it is the label under which the supplementary requirements, the heat treatment and the testing an order must carry are assembled. Two pipes can share a base plate specification and still be different deliverables once the class differs. That is why a requisition saying only 'A671 pipe' is not yet an order: it names the standard and leaves the class, which is where the testing and treatment provisions actually live. The class is written onto the requirement, not chosen silently by whoever supplies it.
They are two separate specifications for two different temperature services, and they are not interchangeable. A671 is written for lower-temperature and atmospheric service; A672 is the moderate-temperature pressure-service specification for electric-fusion-welded pipe. Which one applies follows from the design temperature and the duty, not from the welding process — both are EF-welded, and that shared process is exactly why buyers confuse them. Settle the temperature service first, then the specification follows from it. If your design basis names A672, we quote A672 rather than offering the other.
Not by the standard's name alone, and this is where an EF-welded offer most often overreaches. The material specification governs what the pipe is made of, how it is welded and what is tested; it is not a pressure-design approval. Pressure design, wall thickness for the duty and the acceptance of the welded joint under your construction code are engineering-design responsibilities that sit with your project, ASME or equivalent. The presence of a specified welding process in the standard does not certify it against your system.
The welding the pipe is made with and the non-destructive examination it carries are both inputs the order should fix, because they are not the same thing and neither is implied by the class alone. What the specification provides for and what your project separately requires are two layers: the standard's provisions, and the supplementary requirements your order adds on top. Naming the welding process and the NDT scope your project expects makes the certificate comparable with the other offers you are holding — and it is the field most often left open on an A671 enquiry.
A671 is the standard for electric-fusion-welded pipe, which is a large-diameter product form in its usual application, but the dimensions, the base plate and the wall thickness your project needs are inputs you state rather than figures we publish. Give us the outside diameter, the wall thickness, the length and the base plate specification alongside the class and the temperature service, and the desk confirms the offer against that stated basis. Price on request, confirmed with the commercial terms on the enquiry.
Still settling the basis?
Send the enquiry with what you have stated and flag what is still open. The desk will tell you which inputs it needs before it can price, rather than returning a number built on assumptions.
Noor Deira Steel Trading L.L.C.
Office 3303, Churchill Executive Tower, Business Bay, Dubai, United Arab Emirates · Monday to Saturday, 8.00 AM to 6.00 PM, Sunday closed.
Request a quote
Build the designation as far as your project allows and send it with your requirement. The commercial desk confirms availability, price and the welding and examination scope from what you state — price on request.
What an A671 enquiry needs
The base plate specification the pipe is assembled from
The class the order is placed against
The temperature service — lower-temperature or atmospheric
The governing edition of the material specification
Outside diameter, wall thickness and length
The welding process and the NDT scope your project expects
The construction code governing the welded joint
Quantity, delivery point and required date
Prefer to talk it through?
