Component Breakdown of Sealless High Pressure Pump Skids

This article describes a complete skid is sized and its compnents. The same steps apply to other pump types; the hardware shown is for Wanner Hydra-Cell Pro^® sealless positive-displacement pumps.

Model choice is more than GPM and PSI. Water and mild liquid are usually straightforward. Slurry, extreme temperature and a tight flow band can push you to a larger frame than the raw rate suggests.

The web inquiry form asks for what we need. Leave blank what does not apply. That data sizes the pump and sets wetted materials.

Capacity is GPM or GPH. We need the maximum rate so the frame can physically displace it.

If the liquid is abrasive, hot, viscous or shear-sensitive we may oversize — sometimes up to twice the required flow — so the shaft turns slower.

Shaft Speed and Positive Displacement Pumps

A Hydra-Cell Pro^®, like other PD pumps, moves a fixed volume per turn. Discharge pressure barely changes that volume. Internal check valves set direction. Flow rate is velocity across disc and seat. Abrasive solids wear those faces faster at higher velocity, so a slower shaft helps. Tungsten carbide or ceramic valves stretch that life further.

Viscosity and temperature often point the same way: turn the pump slower.

Discharge pressure is the other driver. The Hydra-Cell Pro line covers about 30 PSI to 5,000 PSI. Choices thin out above 1,000 PSI. Pressure plus maximum flow sets motor horsepower. Engine, air and hydraulic motors exist; most of our skids use electric motors.

Each model has an HPr formula. If you need a flow range, the motor still has to make shaft torque at the low end. We use a worksheet from model, minimum flow and maximum pressure. After that: explosion-proof or other special motor features, and on small HP whether single- or three-phase is available.

The pump model sets the NEMA frame. That frame is how the shafts get joined.

Most packages use a three-piece shaft coupling: two geared stainless hubs on the shafts and a sleeve that ties them together. A few models have a hollow shaft that takes the motor shaft directly — no coupler, no coupling guard. Some customers use belts and pulleys and set pump RPM with pulley ratio.

Alignment matters. A loose or cocked couple kills the coupling and can load pump or motor seals. Belts need the same care if you want belt life. Alignment comes from an adapter or from a multi-level base, depending on frame size and whether the drive is direct or belted.

Frames through about 20 GPM can bolt to the motor through an adapter. That adapter is an epoxy-coated cast-aluminum spool. One face matches the pump cap-screw pattern; the other matches the NEMA C-face. Motor NEMA frame therefore sets half the coupling, the adapter and the baseplate.

If there is no adapter for that pump/motor pair, the baseplate does the aligning. Each base is drilled for a given pump and motor. Nuts are welded on the underside so all fasteners go in from the top.

If pump and motor shaft heights differ, the base has a raised pad so the shafts line up in both planes.

With an adapter the pump can hang off the motor — no separate pump foot on the base. The motor can hang off the adapter too on some oversized, low-pressure jobs.

You can skip the Wanner^® base and bolt the adapter package to whatever pad you have. The Wanner base lets that same package sit on the floor and has holes if you want it lagged down.

Flex-coupled systems (no adapter) use the same style of base with the elevations already worked out, plus a coupling guard so no one walks into the shafts.

Belt-drive bases are a little more involved. The motor or pump has to slide for belt tension. You skip the adapter and coupling, but the guard is larger and the base costs more, so there is rarely a net savings.

Quotes are itemized so you can drop a base or buy the motor locally if that is cheaper. The same quote usually lists the common extras: sealless pressure regulating valve, VFD, gauges, pipeline strainer and isolation valves.

We size from the application. Factory support is there when the liquid is not simple.

Related Articles

• Assembling a Hydra-Cell Pro^® to a motor with an adapter
• Calculating horsepower required
• Motor sizing for high-temperature liquid
• Sealless pressure regulating valves
• Sizing a high-pressure CNC coolant pump
• Hydra-Cell Pro^® design overview