Before requesting a NOV Type P valve cover, establish which cover assembly the installed module uses. A pump model, an old purchase description or a photograph alone should not be treated as a verified replacement specification. This guide helps organize a document review before parts selection.
Two cover arrangements in the OEM document
NOV document 25-101131 describes TAPR-LOK on page 12: a tapered adjuster spreads locking wedges between the threaded cover and seal retainer, loading the threads and compressing the seal. Page 13 describes FAST-CHANGE as a screw-type arrangement without locking wedges.
The booklet lists FAST-CHANGE availability for 14-P-220, 12-P-160, 10-P-130, 9-P-100, 8-P-80 and 7-P-50, and describes it as standard on 14-P-220. It also states that conversion requires different module studs. These are statements from that document, not confirmation of the configuration now fitted to an individual pump or a promise of current stock.
Separate installed configuration from proposed conversion
Use separate records for a like-for-like replacement request and a proposed change of cover arrangement. For replacement, the review question is whether the requested item matches the verified installed assembly. For conversion, the review must also establish the required related components and applicable approved documentation; a cover-only request does not settle the stud requirement.
The following checklist is editorial guidance for collecting evidence, not an OEM installation procedure:
- Equipment tag, pump model and serial number.
- Module position and module identification, where documented.
- Installed cover type, supported by the applicable drawing or equipment record.
- Assembly drawing number, revision and item positions for the cover, seal retainer and related studs.
- Part numbers with their documentary sources; label unreadable or unverified markings as unresolved.
- Relevant modification history, including the supporting conversion record if one exists.
- Photographs already obtained through authorized safe access, linked to their location and record date.
Do not infer that the absence of a visible wedge in one photograph proves FAST-CHANGE identification. Ask the responsible reviewer to reconcile the image with the assembly documentation. Record conflicting evidence rather than silently choosing whichever identifier matches a catalog entry.
Keep the request reviewable
An effective request can state: installed arrangement, evidence reference, requested item position, confirmed part number if available, and unresolved questions. Keep the current assembly record separate from the proposed replacement list so that a supplier response does not overwrite the equipment history.
If the installed type, stud specification or drawing applicability cannot be confirmed, retain the request as unresolved. Obtain an OEM or authorized technical assessment before treating a proposed set of parts as compatible. This article supplies no pressure rating, tightening method, removal sequence or permission to modify the assembly. Physical work requires the applicable approved procedure, isolation and pressure-release controls, and qualified personnel.
Related model references and source
The NOV 12-P-160 product page and the NOV 14-P-220 product page provide model context. They do not replace configuration-specific drawings or constitute valve-cover fit approval.
Source checked October 8, 2026: NOV, How to Treat Your Type P Triplex Mud Pump, document 25-101131, pages 12–13. The evidence checklist and request format above are editorial recommendations.
Frequently asked questions
How does the source distinguish the two covers?
It describes TAPR-LOK with a tapered adjuster and locking wedges, and FAST-CHANGE as a screw-type arrangement without locking wedges.
Does the pump model prove which cover is currently installed?
No. Confirm the installed assembly using applicable equipment records, drawings and any modification history.
Can a conversion request include only the cover?
That would leave a documented dependency unresolved: NOV states that conversion to FAST-CHANGE requires different studs. Confirm the complete applicable parts requirements.
Is this an installation or tightening guide?
No. It is a document and identification checklist. Use the applicable approved service procedure for physical work.