National 8-P-80 Mud Pump Parts: Rods, Liners and Assembly Matching

The National 8-P-80 catalog identifies a triplex slush pump with a 6-1/4-inch by 8-1/2-inch size designation on its cover. That model identification is useful, but a replacement-parts enquiry also needs the relevant assembly and the installed component size. The supplied material includes power-end and crankshaft drawings alongside separate rod, liner and fluid-end references.

Model and source-reference facts

Keep the power-end and fluid-end requests distinct

A maintenance list may combine a studded discharge module, liner bushing, piston rod and crosshead component. These parts belong to different assemblies and should be entered as separate RFQ lines. In the supplied 8P-80 component list, 1291280 identifies a studded discharge module, 1291165 a liner bushing and 1291277 a piston rod. Copy the full number as written, then add the component description and quantity.

The liner clamp and liner bushing are listed separately, and the intermediate rod wiper seal is distinct from the intermediate rod baffle. Those differences matter when a buyer compares a complete maintenance package with a quotation for one seal or one clamp. Crosshead requests also need the position or handedness taken from the matching drawing; a repeated generic description is not enough to confirm the correct part.

The examples below are selected reference entries, not a complete bill of material or a confirmation of interchangeability.

Details to include with the parts request

Prepare the request with an 8-P-80 nameplate photo, pump serial number, catalog revision and a marked-up drawing showing the required item. Record liner or piston size for wear components and provide a close photograph of any markings. If a part has no readable number, include dimensions and its position in the assembly. These details support a parts comparison without treating a similar-looking item from another P-series model as interchangeable.

For related purchasing information, see mud pump spare parts matching and liner, piston, valve and seat identification. You can contact Pratt Oil with your parts request for review of the model, reference and component details.

Brand and model names identify the equipment described in the source material. Final parts matching depends on the complete pump and assembly information.

Mud King catalogue references for this model

The reference list also includes entries from the Mud King Products expendables catalogue. MK and MKG prefixes identify that supplier catalogue’s numbering. Keep those prefixes and the stated size, valve series, liner outside diameter and source table together. They are not presented as original pump-manufacturer numbers or as a confirmation of fit.