Replacing oil does not by itself document that the main sump was cleaned. For a NOV Type P maintenance handover, keep the condition of the sump identifiable alongside the oil-change work order. This guide concerns cleaning records and their limits; it is not a flushing, filling or return-to-service procedure.
The original maintenance requirement
NOV booklet 25-101131, page 6, requires thorough cleaning of the main gear oil sump at each regular oil change. The stated reason for removing accumulated drilling mud and sludge is to avoid contaminating the replacement oil. The passage also calls for routine cleaning of the sump and power-end frame walls to help heat pass from the lubricant to the surrounding air.
The booklet identifies removal of the sump dipstick cover plate for cleaning access. That statement does not establish a complete access procedure. Authorized personnel must use the applicable current manual and site shutdown, energy-isolation, safe-access and waste-handling requirements before opening equipment. This article supplies no solvent selection, flushing method, cover torque or oil-change interval.
Keep the main sump identifiable
Use the installed equipment identification and the correct manual revision to identify the main sump. A settling-chamber drainage entry is not evidence that the main sump was cleaned. Similarly, a normal oil-level reading cannot establish that deposits have been removed.
The handover should distinguish the sump from the power-end frame walls and state which areas were actually checked. A photograph, where safe and permitted, may supplement a record but should not conceal unobserved or inaccessible areas. Do not infer cleanliness from a photograph of a different location.
Suggested cleaning-to-oil-change checklist
These are editorial documentation fields, not additional NOV requirements:
- Equipment tag, model, serial number, manual revision and work-order reference.
- Date and responsible person for the cleaning activity.
- Main sump and frame-wall areas inspected, with the access location identified.
- Deposits observed before cleaning, described without assuming their cause.
- Work actually completed under the approved procedure and the condition observed afterward.
- Remaining deposits, inaccessible areas or other limitations referred for maintenance review.
- The responsible person's disposition of unresolved items and the reference for any follow-up work.
- A separate reference to the approved oil-change and closure checks, preserving the distinction between cleaning completed and the whole maintenance job completed.
Do not write “sump cleaned” merely because old oil was drained. If cleaning is incomplete, keep that status visible to the person taking over the job. A form entry cannot authorize proceeding past an unresolved maintenance requirement.
Avoid unsupported conclusions
The source explains why cleanliness matters for replacement oil and heat dissipation. It does not supply a temperature improvement, contamination limit or service-life prediction. Do not turn a cleaning record into a claim that overheating has been cured or that the lubricant is suitable. Oil specification, quantity and the applicable acceptance and return-to-service criteria must come from the equipment instructions and authorized maintenance process.
Related equipment and distinct records
NOV 12-P-160 and NOV 14-P-220 are equipment navigation links, not evidence of interchangeable covers, seals or oil quantities. Keep the settling-chamber record and oil-level record separate from the main-sump cleaning entry.
Source and scope
NOV, How to Treat Your Type P Triplex Mud Pump, document 25-101131, page 6, checked 30 September 2026, Beijing time. The cleaning requirement, access reference and stated purposes come from this source. The checklist and handover distinctions are editorial suggestions. Confirm the current instructions for the installed pump before maintenance.
FAQ
Does draining old oil prove the sump is clean?
No. Record the cleaning performed and the observed condition separately from oil drainage.
Does the source give a cleaning chemical or flushing method here?
No. This passage does not specify either, and this guide does not invent one.
Can cleaning be credited with a fixed temperature reduction?
No. The source gives a heat-dissipation rationale, not a quantified temperature result.
How should inaccessible areas be recorded?
Identify them as unverified and refer the limitation through the maintenance process; do not mark them clean by assumption.