Hydra-Cell® Pro is a change inside the hydraulic end that raises 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, Hydra-Cell Pro was announced.
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 packing is gone. A clamped diaphragm is a static seal. That cut a major leak path and a major failure mode. See the piston and plunger comparison.
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.
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 right away. 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.
The reduced valve pocket, once an option, is standard on Pro. 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.
Efficiency here is how little oil you need to make the hydraulic piston. Less oil is better. Before 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%. Pro picks that low-speed, high-pressure corner back up into the 85–95% band. Full speed and full pressure gain about 2%.
You notice it most on low-flow metering — more GPH at the same RPM than the Kel-Cell stack.
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.