Enhancing Hydraulic Efficiency:
The Evolution of Wanner Hydra-Cell Pro^® Pumps to Hydra-Cell Pro^® Series

Wanner Hydra-Cell Pro^® is a change inside the hydraulic end that increases volumetric efficiency. This article adds pictures and history around Wanner^® technical bulletin TB0083 — from the original Hydra-Cell^® to Kel-Cell^® to Pro^®.

People who have been around Wanner^® a long time have watched the sealless line grow without much pause.

William Wanner Sr. received the first Hydra-Cell patent in 1972. William Wanner Jr. formed Wanner Engineering in 1973. Thirty years later Kel-Cell diaphragm-position control was patented so diaphragms would survive inlet cavitation. Twenty years after that, on the company’s 50th anniversary, Wanner Hydra-Cell Pro^® was announced.

What Is the Hydra-Cell?

It is a fast-acting valve that builds a hydraulic piston and then trims that piston to the pressure the pump is working against. The piston moves a diaphragm so chamber volume grows and shrinks — positive displacement. Flow and pressure sit in the same band as piston and plunger pumps, but there are no seals or packing. A clamped diaphragm is a static seal and reduces a leakage path/failure mode common to piston and plunger pumps.  See the piston and plunger comparison.

The Kel-Cell Innovation

The Hydra-Cell valve uses a spring for bias pressure so the hydraulic piston can form. Kel-Cell swapped the long spring for a shorter, stiffer one. That stopped the over-fill that cavitation caused on the original diaphragms. The new spring needed a groove in the cylinder housing so the pump would still prime.

Hydra-Cell Pro

Wanner Hydra-Cell Pro uses two springs instead of one. The groove in the cylinder housing goes away, so the hydraulic piston is more efficient, and position control still keeps a starved or closed inlet from tearing diaphragms during caviation. Hydra-Cell Pro pumps dry-prime and they survive dry running and hard cavitation. The static diaphragm seal is what lets them move liquids that cut cups, packing and mechanical seals on other PD pumps cannot.

Additional Pro Features

The reduced valve pocket, once an option, is standard on Hydra-Cell Pro pumps. The process side of the valve plate is machined closer to the extended diaphragm so there is less unused volume. Less room for solids to sit, and higher volumetric efficiency.

Volumetric Efficiency

Efficiency here is how little oil you need to make the hydraulic piston. Less oil is better. Before Hydra-Cell Pro (also called ADPC — Advanced Diaphragm Position Control), hydraulic efficiency was 85–95% at full shaft speed and full pressure. Full speed at lower pressure could reach 99%. Low speed at full pressure could fall under 50%. Hydra-Cell Pro improves the low-speed, high-pressure performance into the 85–95% band. Full speed and full pressure gain about 2% efficiency.

You notice it most on low-flow metering — more GPH at the same RPM than the Kel-Cell design.

Changed Components

• Cylinder housing has no grooves and is stamped “PG”.
• Pro pistons can go into classic and Kel-Cell pumps, but the internals of the three generations do not mix. A Hydra-Cell Pro upgrade is a complete piston assembly.
• The reduced-pocket valve plate can be retrofit on any existing Hydra-Cell.

As of early 2024, Pro had not been released on the smaller 20, 03 and 04 series. It applies to the 10, 12, 15, 17, 25, 35 and 66 capacity pumps and the Metering Solutions versions of those models.

Hydra-Cell Pro Advantages

• No mechanical seals, packing or cups to leak, wear or replace
  • Less maintenance, downtime and emissions
  • Flow follows RPM from min to max, independent of discharge pressure
  • Metering accuracy that exceeds API 675
• Patented ADPC (Advanced Diaphragm Position Control)
  • Protects the diaphragm on a bad suction condition
  • Can run dry indefinitely without damaging the pump
• Sealless design and horizontal disc check valves
  • Slurries, viscous, corrosive, solids and abrasive fluids
  • Prevents pump damage from cavitation
• Lower total cost of ownership — purchase, energy, service and downtime
• 85% to 99% performance efficiency across the operating range
  • Compact, lighter package

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