The selection workflow starts by separating hydraulic duty from material-handling duty. Flow and head define the hydraulic requirement, but solids character, viscosity, entrained air, route geometry and shutdown behaviour decide the pump family.
A premium pump schedule should show normal rate, minimum stable rate, maximum credible rate, static lift, friction loss, discharge pressure, suction submergence, fluid density, solids description and control mode. Without those values the selection is an opinion, not engineering.
Duty Envelope and Selection Checks
Start selection from the installed duty, not the catalogue name. Define normal flow, minimum controllable flow, maximum credible flow, suction level range, mud density range, viscosity range, solids character, line length, elevation change and receiving-point pressure. Then reject any pump that only works at a clean-water point with no allowance for worn clearances, aerated suction, heavier mud or blocked-discharge protection.
| Check | Engineering use | Reject or redesign if |
|---|---|---|
| Flow basis | Compare required flow against the system curve and downstream equipment demand. | Pump selected from nominal flow only. |
| Suction basis | Check flooded head, fittings, NPSH margin and air-entry points. | Pump has to pull through a starved suction. |
| Solids basis | Classify abrasive solids, sticky cuttings, sludge or chemical solution. | The service is called dirty water with no solids description. |
Duty Screening Table
| Rig Solids-Control and DWM Pump Duty Selection check | Required field evidence | Stop or redesign trigger |
|---|---|---|
| Duty definition | required flow, actual route, fluid condition, operating margin and downstream process response are recorded with units and operating state. | The duty is described only by equipment name or nameplate capacity. |
| Installed-route confirmation | Line length, elevation, valves, receiving point and material condition are checked. | The route cannot be restarted or isolated safely after a stop. |
| Process acceptance | The downstream process becomes stable after the correction. | One gauge improves while flow, quality or reliability gets worse. |
Calculations That Change the Decision
Operational Acceptance Criteria
Specific Engineering Boundary
Selection is complete only after the duty envelope is documented for the worst credible fluid state, not the cleanest one. A good selection note includes normal and upset cases, suction margin, pressure protection, route losses, maintainability and what field reading will trigger a stop.
