Component Breakdown of Hydra-Cell Pumps

Description of components in contact with the pumped liquid

Hydra-Cell Pump liquid end components

 High Pressure Pump System Components Article- Components of Hydra-Cell pumps


Components of a Hydra-Cell Pump
Hydra-Cell pumps are sealless positive displacement pumps whose only components in contact with the pumped fluid are the elastomers and check valve assemblies. This article describes the function of these components, lists the available materials of construction and provides additional information in support of selecting the most appropriate materials for your application.

Most Hydra-cell pumps have a 12-character part number with each character associated with a specific pump characteristic.  Choice of the best suited materials for your application improves reliability and reduces downtime as well as labor and parts costs associated with maintenance.

This article focuses in on the materials in contact with the pumped fluid and their function, which are defined with the 6th – 11th characters of the part number.


The first characters reference the Hydra-Cell pump model, so in the example above the part number is for a model D10 Hydra-Cell pump.  The 4th character references the flow rate at a given RPM.  The purpose of this customization is to establish the desired flow rate at an appropriate fluid velocity; abrasive fluid applications benefit from lower velocities across the internal check valve assemblies because it corresponds directly to reduced check valve wear.

The 5th character describes an aspect about the pump head or the hydraulic cylinder of the pump.  The 12th character is a reference to the type of oil used in the hydraulic end of the pump.  Most applications use a common 10W30 or 10W40 synthetic motor oil although there are specialized applications requiring food contact and other specialty oils.

Hydra-Cell pump head materials

#6: Pump Head Materials & Function
The pump head consists of two parts, the manifold and the check valve plate.  These components often last the life of the pump and are selected based upon chemical compatibility with the pumped fluid.  Hydra-Cell pump heads are offered in a variety of alloy and non-alloy materials:



The pump head is not considered a wear item, even when the fluid is an abrasive slurry.

Hydra-Cell pump elastomer materials

Character #7: Elastomers
These are the diaphragms, o-rings and gaskets – all almost exclusively selected based upon chemical compatibility with the pumped fluid:



Diaphragms are often replaced when replacing the check valves because it is easy to do and “resets the clock” on all the materials within the pump head.  Diaphragms are damaged by chemical incompatibility, over-pressurization and extreme temperatures.  With the exception of PTFE diaphragms, physical wear is only cosmetic.  O-rings and gaskets enforce the desired flow path and are replaced each time the pump is serviced.

Characters #8-9: Valves and Valve Seats
The valve disc sealing against its corresponding valve seat is responsible for maintaining the flow path from inlet to outlet of the pump. Each revolution of the pump shaft causes the valve and seat to “mate” and can cycle up to 30 times per second!  These are the main wear items of Hydra-Cell pumps.  You know they are worn when the flow rate/pressure decreases.  It is a gradual type of wear and not sudden nor catastrophic; just a slightly louder sounding, rougher running pump.

Hydra-Cell pump check valve materials

How long do Hydra-Cell check valves last?
There is no direct answer to this question, we can only estimate based upon prior experience with similar fluids.  Applications involving reclaimed water or machining coolant using stainless steel valves/seats will likely last 6000 hours (8+ months of continuous use).  25% lime slurry applications might last as long, however only if operating the pump at lower RPMs (reducing velocity across the valves/seats) and using an abrasion resistant material such as ceramic.

Selecting the check valve material involves consideration of both chemical compatibility and economical longevity.  Stainless steel valves for a high-pressure water application operated only 8 hours a day could last over 2 years; it would be tough justifying the cost of using tungsten carbide even though that material lasts 20 times longer (40 years!) because it costs 36 times more than SS.  We select check valve materials that will last approximately 6-9 months given what we know about similar customers and applications.  The following materials are suitable for 15 to 250°F:



Character #10: Valve Spring
The valve spring is the only component in contact with the pumped fluid that must be an alloy material.  The springs are not considered a wear item unless the fluid is not chemically compatible.  These ensures quick re-seating of the check valve and are compatible with temperatures of 15 to 250°F:



Character #11: Valve Spring Retainer
The retainer is the component which compresses the spring which in-turn seals the valve against its seat.  The compression of the retainer is accomplished by sandwiching it between the pump manifold and valve seat.  This is not considered to be a wear item as they are damaged by chemical incompatibility or an upset condition involving an extreme temperature.  Retainers are available in the following materials:



Our web-based repair kit part number and pricing calculator (Click Here) will convert your pump part number into the three repair kit part numbers (elastomers only, check valves only and a complete kit containing both).


 Hydra-Cell pump repair kit pricing calculator