A 500 MW unit can draw around 10 MW just running its boiler feedwater pump. Let that pump trip and the boiler cannot fire — full unit shutdown, not a derate. Most BFP failures don't start as a trip. They start as a slightly high suction strainer differential, a mechanical seal weeping a little more than yesterday, or a bearing temperature creeping up half a degree at a time. Sign up to log every daily walk against baseline and route any drifting reading straight into a work order.
Why It Matters
A feedwater pump failing results in a large capacity reduction or full shutdown, which makes it both an opportunity loss and a safety issue. Distortion from running off its design flow window causes flashing, internal rubbing, worn wear rings, seal bushing wear, and bearing damage — every one of which shows up in a daily walk long before it shows up as a trip.
The Walk In Three Stops
Suction Side
Check suction strainer differential pressure and suction pressure against normal, and confirm the deaerator level is holding steady before the pump ever starts working hard.
Pump Body
Walk the mechanical seal, balance disc leak-off line, and all bearing points in sequence, listening for anything that doesn't sound like yesterday.
Discharge & Log
Record discharge pressure and temperature, compare the day's numbers against the pump curve baseline, and sign off with any finding flagged clearly for the next shift.
The Daily Walk Checklist
Check suction strainer differential pressure: a rising DP across the strainer means debris is building up, and a starved suction is one of the fastest routes to cavitation and internal damage
Inspect the mechanical seal for leakage: weekly checks target the seal flush system, but a daily visual pass catches a sudden change well before the scheduled inspection would
Record bearing temperatures at every bearing point: most start permissives cap bearing temperature well below 75°C — log the actual reading, not just a pass or fail against that ceiling
Verify balance disc leak-off pressure and flow: the balance disc manages axial thrust, and a shifting leak-off reading is often the earliest sign of internal wear ring or disc face wear
Compare suction and discharge readings against the pump curve: flow, head, and pressure drifting away from commissioning data flags declining hydraulic performance before it becomes a trip
Every Reading Compared, Every Drift Actioned
Oxmaint tracks strainer DP, seal condition, bearing temperature, and balance disc readings against your pump curve baseline automatically, and raises a work order the moment a reading drifts out of range. Sign up for a free trial to run it on your own BFP, or book a demo to see it configured for your fleet.
Why Suction Side Discipline Matters Most
Almost every serious BFP failure traces back to the pump running outside its intended flow window, and that almost always starts on the suction side. A clogged strainer, a low deaerator level, or a partially closed suction valve all starve the pump of the flow it needs, and running below minimum continuous flow raises fluid temperature fast enough to damage seals and bearings within a single shift. The fix is not a complicated inspection — it's checking the same three suction readings at the same time every day, so a slow drift in strainer DP or suction pressure gets caught while it is still a maintenance item and not an unplanned trip.
What A Drifting Reading Usually Means
| Check Point |
Early Warning Sign |
Likely Cause |
| Suction strainer DP |
Steady rise above normal differential |
Debris accumulation, risk of cavitation |
| Mechanical seal |
Visible leakage increasing shift to shift |
Seal flush issue or face wear |
| Bearing temperature |
Gradual climb toward the start permissive limit |
Lubrication breakdown or misalignment |
| Balance disc leak-off |
Pressure or flow shifting from baseline |
Wear ring or balance disc face wear |
Frequently Asked Questions
Q
Is a daily walk really needed if the DCS already trends these readings?
DCS trending catches large deviations, but a physical walk catches what instrumentation misses — a slight seal weep, an unusual noise, or a strainer housing that's warmer than it should be. The two are complementary, not interchangeable.
Q
Which reading should never wait for shift handover?
A sudden jump in bearing temperature or a sharp change in balance disc leak-off pressure should go to the shift engineer immediately. Both are associated with fast-developing internal damage rather than slow wear.
Q
Does a UK station need digital sign-off for this record, or is paper enough?
Paper logs record the number but rarely connect it to a corrective action, so a drifting reading can sit unactioned for weeks. A digital, technician-attributed record gives you a clean audit trail and links every finding straight to a work order.
Catch The Drift Before It Becomes A Trip
Oxmaint logs every suction strainer, seal, bearing, and balance disc reading against your pump curve baseline, and turns any abnormal finding into a work order the moment it's recorded. Sign up for a free trial to build your own BFP walk checklist, or book a demo to see it set up for your station.
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