RFQ document checklist for pipe flanges

Prepare your pipe flange RFQ with the flange type, standard and edition, size, pressure class, facing, bore, material and quantity. Include the destination, requested delivery date and required material test certificate (MTC), inspection and drawing scope.

Use this checklist to prepare one enquiry package. Mark unresolved details for clarification and keep item numbers consistent across the list, drawings and specifications.

Size, pipe wall, and bore (especially weld neck)

Nominal size alone does not fix the welding end or finished bore of a weld-neck flange. State NPS or DN consistently (do not mix systems without naming the governing standard), and add either:

the connected pipe outside diameter and wall schedule (or wall thickness), or
the required finished bore / weld-end machining note.

Field	What to confirm
☐ NPS or DN	One size system; name the standard if both appear on drawings
☐ Pipe O.D. + wall / schedule	Or finished bore for the welding end
☐ Flange type	Weld neck, slip-on, blind, or other
☐ Quantity	Separate line items when sizes differ

For product details and dimensional references, see weld-neck flanges and our pipe flange range.

Standard, pressure class, and facing

Name the governing dimensional standard and the edition confirmed by the project, the pressure class or PN (match Class vs PN to the standard system), and the facing / mating connection.

Field	What to confirm
☐ Dimensional standard + edition	e.g. ASME B16.5 or the project drawing – edition per project confirmation
☐ Pressure class / PN	Match the standard’s designation system
☐ Facing	RF, FF, RTJ, or as specified; note mating flange / gasket if they affect review
☐ Series (if ASME B16.47)	Series A or Series B when that standard applies

ASME B16.5 is a widely used dimensional standard for pipe flanges in the NPS 1/2-24 range. Final dimensions follow the buyer’s confirmed standard edition and approved drawing. Calculators and other references: technical.

Material grade and document scope

State the material standard and grade, and the material / inspection documents you need with the quotation, not after price comparison.

Field	What to confirm
☐ Material grade	e.g. ASTM A105, ASTM A182 F316L – condition if known
☐ MTC type	EN 10204 3.1 or 3.2 (see FAQ below); buyer inspection and test plan (ITP) / specification governs
☐ Traceability	How heat or lot numbers must link markings to material records
☐ Extra tests	Positive material identification (PMI), nondestructive examination (NDE), or other project-required tests

Specify required heat treatment and supplementary requirements. Identify which documents are needed for quotation review and which are to be supplied with the actual goods. A sample certificate is for format review; final records must relate to the supplied material.

Drawings and approval data

For non-standard geometry or replacement items, attach the approval drawing or item reference with revision. Mark critical features, mating dimensions, and open tolerances before manufacture review.

Field	What to confirm
☐ Drawing / item reference	Revision clearly stated
☐ Critical features	Bore, hub, welding end, bolt pattern, facing
☐ Open questions	Mark unknowns so the first reply can close them

A photograph can help identify a replacement, but it does not establish every ordered dimension. Attach a dimensioned drawing and identify the mating flange or equipment connection where relevant.

Inspection and witness scope

Put inspection scope in the same RFQ as sizes and materials so quotes stay comparable. Adding 3.2 certificate scope or third-party inspection after price comparison often changes cost and schedule.

Field	What to confirm
☐ Inspection scope	Material records, dimensional checks, special testing, marking / packing
☐ Witness points	Which steps require hold or witness
☐ Third-party inspection (TPI)	State the nominated inspection body, required activities and notification period; identify arrangements still to be agreed

Photos and document types: quality & inspection.

Packing, marking, and destination

Destination and packing assumptions affect how complete a quotation can be. State what you need before dispatch.

Field	What to confirm
☐ Destination	Country / port or project site as known
☐ Surface / end protection	Flange-face and pipe-end protection as required
☐ Case / pallet packing	Separators, crates, or pallets
☐ Shipping marks	Marking content required on packages

State the requested delivery date and quotation delivery terms. Identify any special preservation or export-packing requirements so they can be included in the offer.

Copy the template and send your RFQ

Tick the fields above (or paste the tables into your email).
Attach drawings, ITP / inspection scope, and material notes where available.
Mark open questions clearly.
Email the package to info@lkpiping.com.

Subject: Pipe Flanges RFQ — [Project / Reference]
RFQ reference and revision:
Flange type and quantity per item:
Standard and required edition:
Size and units:
Pressure class / PN and series where applicable:
Facing and required surface finish:
Mating pipe outside diameter and wall / schedule:
Required bore or weld-end drawing:
Material specification, grade and heat treatment:
Inspection certificate and traceability requirements:
Additional testing, witness / hold points:
Drawings and specification revisions:
Protection, packing and shipping marks:
Destination, delivery terms and requested date:
Open points requiring clarification:

Please identify deviations, exclusions and assumptions in your offer.

Send RFQ by Email → · Contact LeKe Piping →

Example line item (example only – not a quotation):

Weld-neck flange, ASME B16.5 (edition per project), NPS 6, Class 150, RF, bore to match Sch 40 pipe, ASTM A105, qty 8, destination (state), MTC EN 10204 3.1, inspection scope as attached.

FAQ

What should a pipe flange RFQ document package include?

State flange type (for example weld neck, slip-on, or blind), the dimensional standard and edition, NPS or DN, pressure class or PN, facing, bore or matching pipe schedule, material grade, quantity, destination, and the documents you need, such as EN 10204 material certification, inspection / TPI scope, and drawing revision. Write these once, then send the package to the manufacturer.

Why isn’t NPS alone enough for a weld-neck flange RFQ?

The welding end and finished bore must match the connected pipe wall or schedule. Nominal size alone does not fix the inner diameter. Missing bore or schedule is a common reason for rework clarification on weld-neck enquiries.

When do I state EN 10204 3.1 vs 3.2?

State 3.1 or 3.2 in the first RFQ. Under EN 10204, type 3.1 is an inspection certificate issued by the manufacturer’s authorized inspection representative independent of the manufacturing department. Type 3.2 is confirmed by both the manufacturer’s authorized inspection representative, independent of manufacturing, and either the purchaser’s authorized inspection representative or an inspector designated by official regulations. A third-party inspection report alone is not a substitute for the specified inspection certificate. Use 3.2 when the buyer’s ITP or project specification requires it. Buyer documents govern. Agree the certificate type, inspection scope and submission timing before ordering.