TL;DR
Read the NOV 7-P-50 performance chart by matching the model heading, speed row, liner column and footnotes before quoting a value.
- Keep rated speed and input horsepower together; a faster printed row is not automatically the rated row.
- Preserve the pressure, flow and power labels with their units.
- Keep the chart's efficiency assumptions with any extracted example.
- Treat chart values as document data, not a measurement or permission to operate a particular pump.
This article is a reading guide for the cited chart, not a pump selection result or a pressure-setting procedure.
Scope: identify the table and equipment
The source is NOV booklet 25-101131, PDF pages 27–28. Page 28 contains separate 7-P-50 and 8-P-80 charts. Confirm the chart heading before selecting a row; being on the same page does not make the two models' values interchangeable. Record the document identity and applicable revision if confirmed, without inventing a revision number.
The examples below describe this source. Applicability to an installed pump requires its identity, configuration and current approved operating documents. If a catalog summary disagrees with the original chart, keep both source references and resolve the discrepancy before using either for an operating decision. This article does not reconcile existing catalog ratings.
Which row is the rated row?
Use the dagger-marked speed and input fields to identify the rated row. The 7-P-50 chart on page 28 marks 165 SPM and 500 input HP; the same row lists 450 hydraulic HP. A separate 185 SPM row lists 560 input HP and 504 hydraulic HP. The footnote identifies the dagger as rated speed and input horsepower. Do not relabel the faster row as the rated condition merely because it appears first.
Keep input and hydraulic horsepower in different fields. An extracted number labelled only “HP” loses the distinction made by the source. Retain the selected row reference so another reader can verify it.
How do the liner column and units stay together?
Select the liner column, then read the flow at the selected speed. One source example is the 6-inch (152.4 mm) column at 165 SPM: 470 GPM (1777 LPM). That column's maximum discharge-pressure heading is 1645 psi (115.7 kg/cm²). These are paired document entries with different labels, not a field measurement or a recommended setpoint. NOV page 28.
Save pressure and flow separately with their units and row/column references. Do not copy a flow from one liner column and a pressure from another. Preserve the source's rounded unit pair rather than presenting a fresh conversion as an additional OEM figure. “Volume per stroke” is a separate row, not another flow-per-minute label.
What do the footnotes and specification labels mean?
Keep the chart assumptions visible: its footnote specifies 90% mechanical efficiency and 100% volumetric efficiency. They describe the tabulation basis; they do not establish the actual efficiency of an installed, worn or modified pump. NOV page 28.
The specification table on page 27 separately labels fluid-cylinder hydrostatic test pressure. A test-pressure entry must retain that label; it is not the performance chart's maximum discharge-pressure heading and cannot serve as a working-pressure instruction. Confirm operating limits through applicable equipment documents and the responsible technical reviewer.
Chart-reading checklist
These are suggested editorial record fields:
- Equipment identity: model, serial identity if available and installed configuration still to confirm.
- Source identity: file number, confirmed revision if available, page and exact chart title.
- Row identity: speed, input horsepower, hydraulic horsepower and any rated-row marker.
- Column identity: liner size, pressure heading, selected flow and original unit pairs.
- Context: efficiency assumptions and whether an entry is performance, per-stroke volume or test-pressure data.
- Uncertainty: conflicting catalog summaries, missing configuration evidence and the person responsible for resolving them.
Retain the source excerpt with the record. Do not fill missing data with an assumed operating limit or an “approved” status. Use the pump model directory for navigation; catalog entries do not settle an unresolved chart discrepancy.
FAQ
Is the fastest printed row automatically the rated row?
No. Preserve the source's rated-row marker and its explanation; a separately printed faster row is not automatically the rated condition.
Are input HP and hydraulic HP the same field?
No. Keep their separate source labels rather than recording an unqualified horsepower number.
Does a chart flow guarantee actual flow from my pump?
No. A tabulated value has source assumptions and does not verify the condition, configuration or measured performance of an installed pump.
Can fluid-cylinder test pressure be used as a working-pressure setting?
No. Preserve the test-pressure label and obtain the applicable approved operating limits separately.
Source and related records
Original source: NOV, How to Treat Your Type P Triplex Mud Pump, document 25-101131, PDF pages 27–28. Both original page images and extracted text were checked on October 8, 2026, Los Angeles time. This article reproduces selected examples, not the full tables.
Related document tasks: 7-P-50 liner pilot bushing identification and IADC checklist row mapping. This article concerns performance labels and units; it does not provide their maintenance or fastener instructions.
Next step
For a technical document inquiry, provide pump identity, the chart page, selected liner column and speed row, plus any conflicting source excerpt. Obtain equipment applicability and operating-limit confirmation before converting a reading record into a selection or operating instruction.