100.1 m3/h at 348 kPa Is a Requirement, Not a Pump Curve

Two numbers are the entire performance record for these pumps: the primary loop at 100.1 m³/h against at least 348 kPa, the secondary loop at 67.3 m³/h against at least 499 kPa [TARGET]. Plot those two points on a blank sheet and the sheet is still blank. The distribution-unit review files them under a category it names precisely — selection not completed — and then lists what is absent. No head-capacity curve, no power figure, no efficiency figure, no net positive suction head requirement, no nameplate attachment; the pump model and its listing status undetermined, the drive model, current and derating undetermined. The impact line is the sentence that should survive into any procurement conversation: a calculated requirement is not the pump's actual operating point.

A Duty Point Cannot Judge Delivery, Rating, or Cost

Because the duty point is a requirement, four things cannot yet be judged — whether the pump delivers, whether it stays within rating, what it costs to run, and how long its certification takes. The finding says that and stops. It does not say the pump is unsuitable, and its status is open rather than rejected.

The two figures arrived from a sizing calculation and a supplier parameter-return sheet, and the reviewer names both provenances rather than presenting the numbers as supplied performance. That distinction is doing the work. A duty point states where the network wants the pump to sit; a curve states where it will actually sit, how power varies along the way, and how close the selection runs to cavitation. Only the second can answer the first.

Evidence Is Required Per Pump Tag, Not Per Document

What the reviewer asks for is a list against each tag:

• complete pump, motor and drive model designations
• the manufacturer's curves
• the 60 Hz rating and the speed-control range
• single-pump piping capability
• derating and overload behaviour
• nameplates
• the protection combination
• the listing coverage

Six of those cannot be inferred from a duty point at all. A reader grouping the items differently would land elsewhere. The count is this article's arithmetic on the reviewer's list, not a count the reviewer gives.

The duty point's own basis is unsettled

A second finding is why this is not simply a matter of waiting for paperwork. Two documents carrying the same date name the same heat-exchanger model with different item identifiers and different rating points — 67.3 and 100.1 m³/h at 69.2 and 81.1 kPa in one, 52.2 and 77.6 m³/h at 42.76 and 50.30 kPa in the other [MODELED]. Estimated on the first document's fluid properties, the second's rating point corresponds to roughly 700 kW rather than 900 kW.

Then the reviewer does what distinguishes a review from an objection: the finding states that this is not sufficient to conclude the delivered unit can only achieve 700 kW, since it may be the same plate type selected at a different point. What is concluded is narrower and harder to argue with — the supply record is not closed — and the remedy sought is a written manufacturer statement relating the two item identifiers plus a guaranteed 900 kW point for the actual supplied model.

Partial Listing Pages Do Not Confirm the Specific Unit

A third finding makes the pattern visible in another discipline. It records a listing attachment supplied as two printed pages out of four, covering a refrigerant heat-exchanger category certified for one national market, with a series name on the attached page and the missing pages not provided.

The reading is symmetrical in both directions, which is what makes it usable. The attachment proves that material for some series in one market was received; it does not confirm the specific item identifier, factory and service conditions for the intended duty and market, and it does not evidence listing of the complete unit. In the other direction, the missing pages cannot be read backwards as evidence that the manufacturer holds no listing for that market.

The Enquiry May Send Scale, Not a Bill of Materials

Upstream of all three findings, the master enquiry package sets the same discipline. Its quantity table declares a single purpose — letting bidders understand the scale of the enquiry and organise capacity — and prohibits use as a procurement quantity, an investment basis or a bill of materials. Its declared unchanged items carry a standing prohibition on inventing manufacturers, model designations, unit prices, certificate numbers, certification status or delivery times. Its long-lead register lists the distribution unit as blocked on an information-technology-side specification that is not fixed, alongside the hydraulic interface and the four-parameter rated capacity. The evidence gap and the register entry are one gap seen from two documents. Closing either alone produces a schedule rather than a selection.

Limits and open items

All three findings are recorded open. No pump has been selected, no listing confirmed and no order placed. Vendor identity, model designations, item identifiers and certificate numbers are withheld here. [HOLD]

The 100.1 and 67.3 m³/h figures remain requirements, not operating points. The 69.2 / 81.1 against 42.76 / 50.30 kPa pair, the 700 against 900 kW estimate, and the two-of-four listing pages are properties of the submitted package, not of any installed machine. [MODELED]

One manufacturer curve at 60 Hz for the named tag, with the duty point plotted on it and the nameplate attached, would move the pump finding from selection-not-completed to a reviewable selection in a single step — and could equally show the duty point sitting near the end of that curve. Which tag gets asked first?

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Source: K&K Data Service Inc., “100.1 m3/h at 348 kPa Is a Requirement, Not a Pump Curve,” https://www.kkdatasvc.com/lab/heat-rejection-and-pue/100-1-m3-h-at-348-kpa-is-a-requirement-not-a-pump-curve/.