ASME B16.10 Face-to-Face — Matching Valve Length to the Pipe Run
Face-to-face length decides whether a valve drops into an existing spool. ASME B16.10 tabulates F-F for many valve types and Classes. Always state B16.10 (or EN 558) on replacement RFQs.
Quick selection
For ASME flanged/BW valves, cite B16.10. For EN systems, cite EN 558. Measure existing F-F on brownfield jobs.
Comparison table
| Factor | B16.10 role | Still specify separately |
|---|---|---|
| Defines | End-to-end / face-to-face lengths | Flange OD, PCD (B16.5 / EN 1092) |
| Varies with | Valve type, Class, pattern | Operator, gear, actuator envelope |
| Wafer products | Often manufacturer F-F | Wafer butterfly / check thickness |
| Replacement risk | Wrong F-F = pipe cut or spool | Survey existing dimension |
| Buyer action | “F-F per ASME B16.10” + type/Class | Send existing F-F if brownfield |
Brownfield tip
Photograph nameplate and measure F-F between flange faces.
- Gear operators change centre-of-gravity, not F-F.
- API 6D end-to-end may differ — confirm project standard.
RFQ wording that works
- “Flanged gate, Class 150, F-F per ASME B16.10, RF, WCB, size __ (existing F-F ___ mm if known).”
FAQ
Does Class change F-F?
Often yes — higher Class valves are longer per B16.10.
Is wafer butterfly in B16.10 like a gate?
Wafer butterfly F-F is typically a short manufacturer dimension.
B16.10 vs ISO 5752?
Related concepts; cite the project document.
Can you shorten F-F?
Only if piping allows and manufacturer offers it.
Related RFQs and hubs
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