MNT.10:5 - Archetypal Grounding

For the extended constructed PS17 case, the tested installed configuration is C42, with the bearing replacement recorded in MNT.9. The following values are invented to demonstrate a comparison; they are not pump acceptance limits.

The case’s agreed immediate-duty basis requires at least 20 litres per second at a differential pressure of at least 150 kilopascals during a 30-minute representative run. Its supplied acceptance rule is simple comparison of the reported values with those limits, using an already qualified measurement basis for this range and duty. The premise includes a prior assessment of calibration and measurement uncertainty, with the resulting decision risk accepted for this limited claim; it does not assume zero uncertainty or make simple comparison suitable for every use. Instrument drift or changed measurement conditions that invalidate that assessment reopen the comparison.

Under those supplied conditions, the constructed observation is 20.8 litres per second at 154 kilopascals throughout that run, with the applicable equipment-specific condition checks also satisfied: 20.8 exceeds 20 and 154 exceeds 150 under the stated rule. The 45-minute test allowance in MNT.7 includes this run and its controlled transitions.

Those observations support the stated immediate duty in the tested envelope. They do not establish performance at an untested winter peak, an as-new lifetime or elimination of the long-horizon recurrence mechanism. The operator receives that scope explicitly.

If the loaded test instead reaches only 18 litres per second, the performed bearing replacement can still be correctly recorded while the required functioning claim fails. The team returns to diagnosis or the relevant engineering question. A test record with a completed checkbox cannot convert that result into restored service.