Two quotations for “the same” valve can differ by 40% — and the cheaper one is sometimes the better product. The gap is almost never dishonesty; it is unstated differences. Here is the checklist we use internally when normalizing offers for clients.
The 10-Point Comparison Checklist
- Design standard & edition — API 600 vs generic B16.34 gate: different wall thickness, different cost. Standards decoder here.
- Body material & origin — WCB is WCB, but foundry origin drives both price and approval on EPC vendor lists.
- Trim number — 13Cr (Trim 1/8) vs Stellite (Trim 5/16) can be 20% of valve cost. Trim codes explained.
- Bonnet type — bolted vs welded vs pressure-seal on small bore changes both price and leak performance.
- Overlays — NACE, fire-safe (API 607), low-E (ISO 15848-1), cryogenic (BS 6364): a quote silently omitting one overlay looks cheaper and fails document review later.
- Testing level — standard API 598/EN 12266 vs added cryo tests, PMI, witnessed inspection.
- Documentation — EN 10204 3.1 baseline vs 3.2 third-party; IOMs, weld maps, NDE reports. Certificate guide.
- Operator scope — bare stem vs handwheel vs gear vs actuator; ISO 5211 pad included or not.
- Delivery terms — EXW factory vs DAP site is routinely 5–10% on international orders; check packing spec for sea freight.
- Warranty & origin certificates — ask explicitly; retrofit paperwork after shipment is painful.
The Two-Minute Method
Build a one-line spec string for each offer — e.g. 6” 150# API 600 WCB/Trim 8, bolted bonnet, RF, API 598, 3.1, bare stem, EXW — and lay the strings side by side. Every difference becomes visible in seconds, and the “40% gap” explains itself.
The Ten Points, Expanded
Two quotations for “the same” valve rarely describe the same product. Normalise them on these ten dimensions before comparing any number:
- Design standard and edition. API 600, API 602, API 623, ASME B16.34, EN 1984 — and which edition. A valve built to an older edition is not automatically non-compliant, but it is not automatically equal either.
- Pressure class and the basis of the rating. Class 150/300/800 is not a pressure; it is a rating curve. Compare the working pressure at the actual design temperature, not the class number.
- Body and trim materials, by grade. “Stainless” is not a specification. WCB, CF8M, F316, F51 — and the trim number where the standard uses one.
- Seat type and leakage acceptance. Resilient or metal seated, and the leakage criterion with its rate letter or allowance. This single line frequently explains a large price gap.
- End connections and face-to-face dimensions. Flanged to which standard and facing, grooved, threaded, butt weld with what schedule — and whether the face-to-face matches the space in the drawing.
- Certifications actually included. API 607 fire-safe, UL/FM listing, PED/CE, NACE MR0175, ISO 15848-1 low emission. Each has a cost; each is often assumed rather than quoted.
- Documentation type. EN 10204 2.2, 3.1 or 3.2 — and whether test certificates, IOM manuals and dimensional drawings are included or billed.
- Actuation scope. Bare stem, lever, gear operator, or actuator mounted and tested. “Actuator included” and “actuator mounted, stroked and certified” are different line items.
- Delivery and validity. Ex-stock, made to order, or partially allocated — and how long the price holds. On metal-heavy packages a shorter validity that is honoured beats a longer one that is withdrawn.
- Origin and duty exposure. Country of manufacture, not country of warehouse, and whether duty is included, excluded or unstated.
How to Normalise Two Quotations in Practice
Build a single row per line item with those ten columns and fill it from both quotations. Where a supplier has left a column blank, that is the question to ask — not the price. In most comparisons the apparent gap closes substantially once certifications, documentation type and actuation scope are made explicit, and occasionally it reverses.
The remaining gap is then a real commercial difference, and it can be negotiated on its merits. A gap of 40% that survives normalisation usually means a genuinely different product, a different delivery promise, or a risk someone has not priced.
Frequently Asked Questions
Should I always take the compliant-but-expensive offer?
No — ask the cheaper bidder to re-quote against the full string. If the gap survives spec alignment, negotiate with the expensive one.
Can ValveAtlas do this normalization for us?
Yes — it is a standard part of our quoting: send us competing offers with your datasheet and we return an aligned comparison plus our own bid.
