Keep each pump’s duty point, impeller trim and test curve on the serial that shipped.

A pump is sold on a curve. The buyer states a flow and a head, and the maker answers with a model, an impeller diameter and a motor. Everything that follows, from the casting to the final test on water, must reproduce that choice exactly, whichever fitter or engineer happens to handle the job. Nothing may drift.

In practice the choice is split. The selection sheet is in the sales file and the casting heat is in purchasing. The trim is on a machining card. The test curve is in a spreadsheet the test bay keeps. When a plant reorders a seal or asks why a pump underperforms, the history takes an afternoon to rebuild. Four people each hold one fragment. A day is lost.

An enquiry names a liquid, a temperature, a flow, a head and a suction condition. The sales engineer selects a model from the range, checks the curve, picks the materials of construction, and quotes the pump with motor, baseplate and coupling. Custom jobs go to design for a modified casing or a different shaft sealing arrangement, and the drawing returns to sales before the price is confirmed with the buyer.

Castings arrive from the foundry and are inspected, then machined on lathes and boring machines. The impeller is trimmed to a diameter that fits the duty, and the shaft, sleeve and bearing housing are finished. Assembly adds the mechanical seal, bearings and motor. The test bay runs each pump on water, records flow, head, power and vibration, and prints a curve.