RFQ checklist
Nine data points. With all nine we can quote against your duty. With size and class alone we can quote against an assumption, which is how suppliers win on price and lose on rating.
The nine
Steam, feedwater and condensate have different erosion and flashing behaviour. Wet steam attacks seats in a way dry superheated steam does not. "Water" and "deaerated feedwater at 280 °C" are different specifications.
With design temperature, it selects the class against the ASME B16.34 rating table for the material. Alone, it does not.
The single most important number and the one most often omitted. It decides the material grade, and above roughly 540 °C it decides whether you need a creep grade at all. Without it, a supplier quoting to your class is guessing at the material - and guessing low wins on price.
If already fixed by the piping class, state it. If not, we will derive it from items 2 and 3, which is more reliable than rounding up.
Nominal size, and for butt weld ends also the pipe schedule and grade. NPS 12 BW is not enough to prepare a weld end correctly.
Normally set by the piping class so the valve matches the pipe it welds into. If you have the piping class extract, that answers this faster than a materials discussion. Trim is a combination - seat, closure member facing, stem, back seat - not a single grade.
BW, SW, NPT, flanged RF or RTJ. On high-pressure steam, butt weld is usually the right answer, and a flanged requirement above Class 900 normally has a maintenance reason worth stating.
Handwheel, gear, electric or pneumatic. To size an actuator we need the maximum differential pressure across the valve, not just the design pressure - they are frequently different and sizing for the wrong one gives an actuator that cannot move the valve.
MTC 3.1 or 3.2, PMI, NDE scope, heat treatment charts, hardness survey, ITP for approval. 3.2 certification cannot be added after the material is ordered, and the NDE scope changes the price. Deciding this at enquiry avoids a variation later.
Useful, if you have it
| Item | Why it helps |
|---|---|
| Quantity and delivery date | Affects forging batching, which is where the lead time actually is |
| Tag numbers | So the quotation maps onto your valve list line by line |
| Client valve specification | We would rather mark it up honestly than agree to general compliance |
| ITP | Send yours and we mark up hold, witness and review |
| Expected start-stop cycles | Changes construction recommendations on cycling plants |
| Site storage period before installation | Changes the preservation specification |
| Certification scheme (PED, IBR, ASME) | Cannot be retrofitted after manufacture |
| Existing valve details, for replacements | Nameplate photo and face-to-face dimension |
If you have a valve list, send that instead
An Excel valve list or MTO with these fields as columns is the most efficient form of enquiry. You get a line-by-line response with a comment against each item - including the lines where we would need a deviation, and the lines where we think the specified valve is wrong for the duty.
The second category is the part worth reading. A quotation that agrees with everything on a valve list has usually not been checked.
What you should get back
- A price and a real lead time, with the constraint named - usually forging supply
- The material grade proposed and the rating basis at your design temperature
- A compliance statement split three ways: comply, comply with clarification, cannot meet
- The document package scope, itemised
- Any recommendation to change what has been specified, with the reason