1. Specifying — what to put in the RFQ
The biggest procurement mistakes are made before vendors are even contacted. A vague RFQ produces wide-spread bids that cannot be compared fairly; a precise RFQ tightens the spread by 20-40% and exposes the real quality differences.
1.1 Required technical fields
Every pump RFQ must specify, at minimum:
| Field | Why it matters | Common omission |
|---|---|---|
| Rated flow Q (m³/h) | Process duty | Often given as “approximate” — vendors quote at their own preferred BEP |
| Rated head H (m) | System resistance at rated flow | Static head and friction often confused — specify both separately |
| Operating range (Q_min to Q_max) | Where pump actually runs across the year | Buyers spec only nominal — vendors size for nominal — pump fails at off-design |
| Fluid name and properties | Density, viscosity, vapor pressure, suspended solids | “Industrial water” is ambiguous; specify temperature, pH, chloride content |
| Operating temperature range | Affects seal selection, materials, NPSH | Stating “ambient” hides freeze risk or hot-process duty |
| NPSHa at suction flange | Buyer’s responsibility to compute | Vendors quote NPSHr but cannot validate margin without NPSHa |
| Acceptance grade (HI 14.6) | Tolerance bands on Q, H, η | Default 1B; specify 1U for critical or API duty |
| Required certifications | API 610, NFPA 20, INMETRO, etc. | Asking for “all applicable” produces zero useful certificates |
| Driver type | Electric / diesel / steam | Cooling and ventilation requirements cascade from this |
| Power source voltage / frequency | Brazil: 220/380/440 V at 60 Hz typical | Imported pumps with 50 Hz-design VFDs need oversize at 60 Hz |
| Mechanical seal vs packing | Cost / leakage / maintenance trade-off | Default mechanical; specify when packing actually wanted |
| Casing material | Cast iron / cast steel / duplex / Hastelloy | Material decided by fluid corrosion, not by buyer preference |
| Documentation language | Portuguese mandatory in Brazil per NBR 16704 §14.4 | English-only docs delay site acceptance |
1.2 Operating envelope — not just the duty point
The single biggest source of pump-failure-after-acceptance is selection based only on the rated duty point, ignoring the actual operating envelope.
A real RFQ specifies the full envelope:
| Condition | Q (m³/h) | H (m) | Hours/year | Notes |
|---|---|---|---|---|
| Minimum | _____ | _____ | _____ | Often lubrication or warmup |
| Normal | _____ | _____ | _____ | Where pump runs most of the time |
| Rated | _____ | _____ | _____ | Design point |
| Maximum | _____ | _____ | _____ | Process upset / demand spike |
| Emergency | _____ | _____ | _____ | Fire, blowdown, etc. |
Vendors evaluate efficiency, NPSH margin, and bearing loading at every condition — not just rated. A pump that is BEP-optimal at rated but runs 60% of the year at minimum-flow duty will wear bearings 5× faster than catalog life expectancy.
1.3 Fluid properties — be explicit
For water-like duty, the standard fields suffice. For anything else, the RFQ must include:
| Property | Why it changes pump selection |
|---|---|
| Density (kg/m³) | Power scales linearly with density |
| Viscosity (cSt at operating temperature) | >100 cSt: centrifugal efficiency drops sharply; >500 cSt: switch to gear |
| Vapor pressure (kPa at operating temperature) | Sets NPSHr requirement |
| Suspended solids (% w/w, particle size) | Determines impeller geometry, wear allowance |
| Corrosivity (chloride content, pH, dissolved gases) | Materials selection |
| Shear sensitivity | Latex / gels / certain emulsions need internal-gear or progressive-cavity |
| Crystallization temperature | Heat-tracing or steam-jacketing required |
| Toxicity / flammability | Affects seal type (mechanical vs sealless), atmosphere classification |
1.4 What NOT to put in the RFQ
These are common but counterproductive RFQ inclusions:
- “Best in class” — undefined, unscoreable, gives the bidder licence to choose any model and call it best
- “Energy efficient” — every vendor will claim this; specify a numeric efficiency floor at duty point instead
- “Robust” — meaningless in a technical document
- Manufacturer name as a requirement — illegal under most public-procurement frameworks (Lei 14.133/2021 in Brazil) and limits competition unnecessarily
- Specific model number — same problem; if you really need a specific model, say “model X or technical equivalent”
- “As per ISO 9001” — ISO 9001 is a process standard, not a product spec; cite product standards (ISO 2858, API 610, NFPA 20)
1.5 RFQ section structure
A well-organized RFQ has four sections:
- Commercial — bidder identification, validity period, payment terms, delivery terms (FCA/FOB/CIF), penalty clauses
- Technical specification — all fields from §1.1, §1.2, §1.3
- Required deliverables — performance curve, certificates, manuals, training, spare-parts list
- Evaluation criteria — scoring weights so bidders know what is valued
A bidder who cannot tell from the RFQ which factor dominates scoring will hedge — submitting a generic bid that wins on no criterion. Spell it out: “Lifecycle energy cost = 35% weight, lead time = 20%, capex = 25%, references = 20%.”
1.6 RFQ template
See templates/rfq-skeleton.md for a
ready-to-edit RFQ structure.
Next section: Vendor short-listing — who to even ask for a bid.