Buyer note: confirm assumptions before quoting
Lead time, MOQ, yield, leak-test scope, machining scope, and landed cost depend on the drawing, alloy, inspection plan, annual volume, and destination market. For current supplier facts, review the supplier capability sheet or send an RFQ package.
# Pump Casing Gasket Face Flatness & Sealing RFQ Checklist: Machining, Surface Finish, and Inspection Records
Pump casing RFQs often mention “pressure-tight” but do not specify the gasket-face details that actually decide sealing and assembly fallout. Suppliers then quote different assumptions about which faces are machined, how flat they are, what surface finish is required, and what evidence is shipped with samples.
This checklist is written for procurement + SQE teams preparing a pump casing RFQ where cover interfaces, gasket faces, and sealing surfaces are critical.
Useful Bohua routes:
- •Pump casing product proof
- •Pump casing pressure-tight RFQ route
- •Pressure-tight pump casing checklist (leak-test + machining scope)
- •Leak-test specification template
- •Structured RFQ upload
1) Identify the sealing interfaces (do not rely on “leak tight”)
Mark the sealing path(s) on the drawing and in the RFQ:
- •gasket face / cover face (and which side is the “primary” seal)
- •O-ring groove(s) and sealing lands
- •threaded ports and plug interfaces that can leak
- •any press-fit or bearing-seat features that can leak through distortion
If multiple covers exist, list each interface separately. “One gasket face” is rarely one face in practice.
2) Flatness requirement (and when it applies)
Flatness can be relevant at different stages:
- •after casting (baseline)
- •after heat treatment (distortion risk stage)
- •after machining (final acceptance stage)
If you only care about final assembly seal, state that the final acceptance flatness is measured after final machining.
Also specify what flatness means for your program:
- •a global flatness callout (entire face)
- •a local zone flatness (only sealing land)
- •a waviness / “oil can” risk statement when the face is thin or ribbed
If you are not sure, ask the supplier to propose a flatness target and document it as a quote assumption (but do not let the quote omit it).
3) Surface finish requirement (Ra / Rz) for gasket faces
If the gasket type is known, surface finish can be non-negotiable.
In the RFQ, state one of:
- •a surface roughness requirement (example: Ra __)
- •“supplier propose surface finish for gasket sealing; include method + measurement in the quote”
Ask for measurement evidence:
RFQ CTA
Have a casting project? Upload your drawing for a fast, structured quote review.
Send the drawing, target alloy, finishing scope, MOQ, and delivery timing. Bohua will review it like a real sourcing project, not a generic contact request.
- •surface roughness measurement method and record format
- •sample location definition (where on the face is measured)
- •whether coating/anodize is on/off the sealing land
4) Machining scope + datums (so quotes match)
Suppliers cannot quote the same risk if the machining plan is ambiguous. In the RFQ, specify:
- •which faces are machined (gasket face yes/no; O-ring groove yes/no; bolt-hole spotface yes/no)
- •datum scheme for machining and inspection (A/B/C)
- •stock allowance assumptions (if you have a preference)
- •whether fixture design is included and how datum repeatability is controlled
If the gasket face is machined, call it out explicitly. Do not assume “it’s obvious”.
5) Bolt pattern, dowels, and alignment features
Seal failures can be alignment failures. Confirm:
- •bolt hole position tolerance (and whether spotfaces are machined)
- •dowel pin locations and fit (if used)
- •whether gasket compression is controlled by a hard stop or “bolt torque only”
If you have a torque spec, attach it. If you don’t, state that gasket compression must be stable and ask for a supplier recommendation.
6) Tie-in to leak / pressure testing (so the same interface is tested)
If a pressure or leak test is required, specify:
- •which interface(s) are tested (cover face only vs full assembly)
- •method (pressure decay / helium / immersion)
- •pressure, hold time, and acceptance threshold
- •sampling vs 100% testing
If the final leak test is performed after assembly, do not ask the casting supplier for per-part leak data — ask for the interface controls (flatness/finish + inspection evidence) instead.
7) Inspection record pack (what to request with samples)
For gasket-face-driven programs, request:
- •ballooned drawing + dimensional layout report
- •CMM report scope including gasket face flatness, bolt pattern position, and any sealing-land geometry
- •surface roughness record for gasket face (if specified)
- •material certificate / chemistry verification (as required by drawing)
- •the leak/pressure test assumptions if the supplier is quoting a test step
Ask suppliers to list which records are included by default vs available on request.
Copy-paste RFQ starter (gasket face + sealing)
> Pump casing gasket face RFQ (copy-paste)
> Files: 2D PDF rev __ ; STEP __ ; interface/gasket stack note __
> Interfaces: cover face __ ; gasket type __ ; O-ring groove yes/no __ ; ports/threads __
> Flatness (final acceptance): __ (after final machining) ; zone vs full-face __
> Surface finish: Ra __ / supplier propose __ ; measurement record required yes/no __
> Machining scope: gasket face __ ; grooves __ ; spotfaces __ ; datums A/B/C __ ; stock allowance assumption __
> Bolt/dowel alignment: bolt holes __ ; dowels __ ; torque spec if known __
> Test context: pressure/leak test method __ ; pressure __ ; acceptance __ ; sampling __
> Inspection records requested: layout __ ; CMM __ ; surface roughness __ ; material cert __ ; traceability fields __
> Quantity + schedule: sample __ ; annual volume __ ; target timing __ ; destination __
Submit a structured RFQ (drawing-ready)
Project CTA
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