The NOV National 7-P-50 is a three-cylinder mud pump whose original design pairs a forged alloy-steel power end with an L-type fluid end and API 7K-certified components. Factory data puts it at 5000 PSI maximum working pressure, 467 GPM maximum flow and a rated speed of 165 SPM. Shijiazhuang Dongli Petroleum Machinery (DLSY) stocks 66 aftermarket items for this pump, including liners, pistons, valves and springs, exported under HS code 84139100.
FAQ
Which liner sizes do you stock for the NOV National 7-P-50?
We stock MK aftermarket liners for the NATIONAL 7-P-50 in 4 in, 4.5 in, 5 in, 5.5 in, 6 in and 6.25 in bores, covering the full factory liner range for this pump.
How does liner size affect 7-P-50 output and pressure?
At the rated 165 SPM, factory data gives: 6.25 in liner 467 GPM at max 2280 PSI; 6 in 430 GPM at 2470 PSI; 5.5 in 361 GPM at 2940 PSI; 5 in 298 GPM at 3560 PSI; 4.5 in 242 GPM at 4395 PSI; 4 in 191 GPM at 5000 PSI. Smaller liners buy pressure, larger liners buy volume.
What fluid-end parts do you offer for the 7-P-50?
Our 7-P-50 line covers 66 distinct items: 12 liners, 9 valves, 3 springs and 5 pistons, plus related hardware. Valve options include G-2 polyurethane valves, plate-type valves with urethane inserts and double-angle designs, plus valve guide inserts and adapters.
Will your parts fit the NATIONAL-badged 7-P-50?
Yes. Our liners and fluid-end wear parts are built as MK aftermarket replacements for the NATIONAL 7-P-50, the same pump now sold under NOV National branding. Share your existing part numbers and we will cross-reference them.
Do you ship 7-P-50 parts to the United States and Canada?
Yes. The United States, Canada and international oil & gas markets are our regular destinations. Parts ship under HS code 84139100 in export packing.
How long do 7-P-50 liners and pistons last?
There is no fixed interval: wear life depends on pump pressure, mud abrasiveness and maintenance practice. Our parts follow OEM fit and material standards so service behavior matches the originals; material details are available on request.