Fiberglass Flange Specification RFQ: Facing, Drilling & Documents Buyers Spec
When buyers search fiberglass flanges (and frp flanges / gre flange / grp flange) before an RFQ, they need the facing, drilling language, flange style and documents frozen so quotes match — here is what to name on the enquiry.
IFGS is a sourcing and QC partner. We connect buyers to licensed partner factories in China and worldwide, confirm the flange fields match the RFQ, compare quotes and run or coordinate pre-shipment QC. IFGS does not own a factory and holds no API license; the license holder is the factory named on its certificate, which you can verify on the API Composite List.
Plain-language map: fiberglass / FRP / GRE / GRP flanges
A fiberglass flange (also called an FRP flange, GRE flange or GRP flange in buyer speech) is the bolted interface on thermoset stick pipe. The labels overlap, but the RFQ still needs a clear product family and resin path so quotes stay comparable.
- Fiberglass / FRP flange — umbrella product noun for a glass-reinforced thermoset flange on stick pipe. Ask which resin and product family the quote covers. Pipe context: FRP pipe buyers guide.
- GRP flange — glass reinforced plastic flange; often paired with polyester or vinyl ester water and industrial stick pipe. Pipe context: GRP pipe buyers guide.
- GRE flange — glass reinforced epoxy flange; usual path for oilfield and related industrial stick-pipe duty. Pipe context: GRE pipe buyers guide.
Two style phrases buyers use (confirm against the offered drawing — vocabulary only, not IFGS catalog standards): full-face FRP/GRE flange versus stub-end-style with backing flange. Elbows, tees and reducers stay on the fittings path — see the fiberglass pipe fittings buyers guide; this post freezes flange hardware fields only.
Spec fields buyers must freeze before RFQ
Write qualitative language on the enquiry. Put the project’s own numbers and named standards in the RFQ; confirm every value against the factory connection drawing and data sheet — do not invent hole counts, PCD, torque or ratings here.
| Spec field | What to write on the RFQ | Why it matters |
|---|---|---|
| Flange style language | Full-face FRP/GRE flange, or stub-end-style with backing flange (buyer vocabulary — confirm against the offered drawing) | Quotes that mix styles are not comparable |
| Facing language | Facing type as the project names (flat face, raised face or other project language) | Gasket and mating equipment fail when facing is vague |
| Drilling / bolt-circle language | Name the mating standard the project cites; never invent hole counts or PCD | Bolt pattern must match valves, spools and equipment |
| Size basis | Same size basis as the stick-pipe RFQ (buyer’s project numbers) | Mismatched size basis breaks the flanged string |
| Gasket / bolting notes | Gasket face notes and bolting notes as the project accepts (no invented torque) | Yard and field assembly need the same notes as the quote |
| Pressure-temperature | As the project specifies; confirm against the factory data sheet | P-T language must match pipe and flange line items |
| Documents | Connection drawing, flange info sheet, ITP/hydrotest plan, marking vs PO | Award and release depend on matching documents |
Full-face vs stub-end + backing (buyer vocabulary)
Buyers often ask for a full-face fiberglass flange or a stub-end-style arrangement with a separate backing flange. Treat both as enquiry language only. Always confirm which arrangement the factory connection drawing offers, and which mating face and bolt pattern the project requires. Do not invent torque, bolt schedules or hole counts in the RFQ — those come from the project documents and the factory drawing.
If the project has not yet chosen the joint family, start with the flanged-joint selector — not this hardware checklist: flanged joint fiberglass pipe buyers guide. That post owns fiberglass flanged versus metal flanged versus other joint families; this post freezes flange hardware fields once flanged is chosen.
Spec family notes (qualitative only)
If an API Spec appears on the project, keep the documents distinct: API Spec 15HR, 15LR, 15S and 17J are four different documents (15HR ≠ 15LR ≠ 15S ≠ 17J). Flanged stick-pipe strings are never API Spec 15S. Quote against the document your end user names, and confirm the producing factory’s data sheet and certificate scope against that named document. IFGS holds no API license; the license holder is whoever the factory certificate names.
GRE and GRP/FRP flanges sit on thermoset (RTR) stick pipe. RTP is thermoplastic and uses a different RFQ path — do not put both under one vague “fiberglass flange” line item. Confirm resin family against the pipe RFQ before you request flange quotes.
RFQ checklist for fiberglass flanges
Copy into the enquiry:
- Flange style language — full-face, or stub-end-style with backing (confirm against factory drawing)
- Facing language — as the project names
- Drilling / mating standard language — name the project’s mating standard; no invented hole counts or PCD
- Size basis — same as the stick-pipe RFQ
- Gasket / bolting notes — as the project accepts (no invented torque)
- Pressure-temperature — project-specified; confirm against factory data sheet
- Documents — connection drawing, flange info sheet, ITP/hydrotest, marking vs PO
- Destination, Incoterm and packing
- QC evidence required before release (inspection report, dimensional checks, hydrotest records)
How buyers qualify a flange producer: check that the producing factory’s scope matches the resin family and the project’s named standard, that the connection drawing matches the RFQ style and drilling language, and that the yard will accept a written ITP. Pre-shipment hold points are covered in the fiberglass pipe pre-shipment inspection checklist.
How IFGS works on this order
IFGS first confirms that flange style, facing, drilling language and documents match the stick-pipe family already named. We then compare quotes from licensed partner factories in China and worldwide that produce the right thermoset flange family, check that each factory’s certificate scope matches the project’s named standard (or Spec family, when cited), agree the ITP, and run or coordinate pre-shipment QC.
See the product range and about IFGS. Pipe, fittings and flanges for the same project can be sourced as separate line items with clear style and resin language — still one coordinated order when helpful.
Next step
Contact us / request a quote
· Ask IFGS AI
FAQ
What is the difference between a fiberglass flange and a metal flange interface?
A fiberglass (FRP/GRE/GRP) flange is the bolted thermoset interface on stick pipe. A metal flange interface uses metallic hardware. Both can be “flanged joints,” but material, facing behaviour and bolting notes differ — freeze material and mating language on the RFQ, and confirm against the factory connection drawing.
Full-face vs stub-end — what should I ask for?
Ask in buyer vocabulary: full-face FRP/GRE flange, or stub-end-style with backing flange. Then require the factory connection drawing that shows which arrangement is actually offered, plus facing and drilling language that matches the project’s mating standard. Do not invent bolt schedules or torque in the enquiry.
Can IFGS source GRE and GRP flanges from licensed partner factories?
Yes. IFGS can source GRE epoxy flanges and GRP/FRP polyester or vinyl ester flanges from licensed partner factories in China and worldwide and coordinate QC. Keep resin family and flange style as clear line items. Contact sales or start with IFGS AI.
What documents should I request before awarding?
Connection drawing, flange info sheet, ITP and hydrotest procedure reference, marking versus purchase order, and the QC evidence you will require before release. Match each document to the style, facing and drilling language already frozen on the RFQ.