A useful discharge-strainer maintenance record connects the equipment identity, the reason work was due and what authorized personnel actually completed. It should not turn a scheduled date into evidence that the strainer was inspected or cleared for service.
What the NOV guidance establishes
NOV document 25-101131, page 20, calls for checking and cleaning the discharge strainer pipe at least monthly. It also says pumping lost-circulation materials may require inspection and cleaning immediately after those pumping operations finish. The monthly interval is therefore not a reason to disregard the additional operating-history trigger.
The same passage warns that neglected routine maintenance can contribute to unusually high pump pressure and washout in the strainer pipe. This does not make an elevated pressure reading a diagnosis of strainer condition. The applicable operating procedure must govern the response to abnormal pressure.
Prepare the document set before physical work
This is an editorial documentation checklist, not an OEM removal sequence. Before scheduling the work, identify:
- Pump tag, model and serial number, and the installed discharge-strainer assembly identifier where confirmed.
- Applicable equipment drawing, maintenance procedure and revision.
- Previous inspection and cleaning dates, with links to the actual completed records.
- Relevant pumping history, including whether lost-circulation materials were pumped and when the operation ended.
- Work-order reference, responsible authorized personnel and any unresolved findings from the previous record.
A missing previous record means the maintenance history is unverified. Do not enter a presumed completion date just to make the schedule look current. Where the installed arrangement or applicable procedure is uncertain, obtain clarification from the responsible maintenance authority or OEM before work proceeds.
Record completion and findings separately
After authorized work, retain what was actually done:
- Inspection date and cleaning date; indicate if either action remains incomplete.
- Observed condition, location of findings and permitted photograph references.
- Deposits or material observed, without guessing composition or cause.
- Any suspected damage referred for assessment, and the referenced assessment result when available.
- Cleaning method and reassembly checks by reference to the applicable approved procedure, not an improvised method in the record.
- Outstanding actions, responsible person and the separate return-to-service decision.
“Cleaned” does not by itself mean “inspected and accepted.” A photograph of removed material does not establish the remaining pipe condition. If an area was not inspected, state that limitation. Do not invent a wear allowance or call suspected washout acceptable without the applicable assessment criteria.
Keep this record separate from pressure-gauge observations
The discharge pressure gauge record captures readings and measurement context. It does not establish that a strainer has been cleaned or that a pressure-relief device works. Likewise, a completed strainer-cleaning entry is not a calibration result or proof of overpressure protection.
The NOV 12-P-160 and NOV 14-P-220 pages provide equipment navigation. Their links do not prove that installed strainer assemblies or service parts are interchangeable.
Physical-work boundary
Do not open a flange or loosen a connection on the basis of this article. Physical inspection and cleaning require authorized personnel following the installed equipment's approved shutdown, isolation, pressure-release verification and safe-access procedures. A zero gauge indication alone is not proof that all pressure is released. This article supplies no fastener torque, replacement-part selection or return-to-service acceptance criteria.
Source and scope
NOV, How to Treat Your Type P Triplex Mud Pump, document 25-101131, page 20, Discharge Strainer; checked 8 October 2026, Los Angeles time. Maintenance timing and the stated consequences of neglected maintenance come from NOV. The record fields and distinctions between completion, findings and acceptance are editorial guidance. No compatibility, availability or delivery commitment is made.
FAQ
Does monthly maintenance cover every operating circumstance?
No. NOV separately notes that pumping lost-circulation materials may require inspection and cleaning immediately after those operations.
Does a high pressure reading prove the strainer is blocked?
No. Record the observation and follow the applicable operating procedure; this article provides no fault diagnosis.
Can a cleaning entry close an unresolved damage finding?
No. Preserve the finding until the appropriate assessment and disposition are documented.
Does this checklist authorize opening the clean-out flange?
No. It is a documentation aid, not isolation verification, a removal procedure or a work permit.