In our repair department, we have several Waukesha Universal Series pumps that roll in and out each day for inspection and repair. And by far the most common cause of failure we see is water or product ingress past the front grease seals and into the gear case. Once water gets in the gear case, the bearings are quick to seize and it’s all over but the crying. Unfortunately, in sanitary applications, where many of these pumps are cleaned by direct spray or washdown, this can happen all too often. Fortunately, there is a surprisingly simple fix to this that we haven’t previously touched on- bearing isolators. What are bearing isolators and how can they help keep your Universal Pump running? Let’s take a closer look.
I think one of the best ways to learn is to take a look at a real-world example and understand the issue as it occurs. For this case study, let’s have a look at a local plant that formulates and molds the trays for many common sauces. Because the product plates and solidifies in about 30 seconds when exposed to any sort of heat or friction, this is an extremely difficult pumping application requiring double mechanical seals with flush and extreme attention being paid when starting up or shutting down.
Typically their failures manifest with failed seals because the pump was not cleaned well enough in advance of a weekend long shutdown. Replacing seals is a pretty easy fix. Occasionally, however, the pump will fail so spectacularly, the product will fail past the seals, past the standard rubber lip seal on the gearcase, and ingress all the way to the bearings causing the pump to almost instantly seize. This is not as simple of a fix, requiring what we call our “standard” rebuild- a complete teardown, followed by replacement of the lip seals, oil seals, grease seals, front bearings, rear bearings, and product seals. This typically isn’t done in the field and needs to be sent to Triplex (or your local SPXFlow distributor) for repair.
While gearcase rebuilds are common, a good repair shop should be able to tell you if they are happening too often. In the case of this customer, it was far too common an occurrence. So instead of just repairing their pumps into perpetuity, we suggested they install Waukesha Cherry Burrell’s optional bearing isolators. While the Waukesha Universal 1, Universal 2, Universal 3, and 5050 gearcase use a rubber lip seal, when Isolators are installed, the rubber lip seal is replaced by nickel plated bronze retainer with Viton o-ring for a more robust, resistant seal. We strongly recommend bearing isolators for any application that frequently has leaking product seals or high-pressure direct spray can risk bearing contamination. In the case of this customer, we went from seeing a pump in our shop every 3-5 months to less than once a year!
Bearing isolators are an option for new pumps and are also field retrofittable, available in a standard kit for pump sizes 006 through 320.
So if you believe your pump application is resulting in premature bearing failure due to ingress of product or cleaning solution into the gearcase, consider bearing isolators for your current or next new Universal series pump. And as always, if you have any questions about any of your Waukesha Cherry Burrell Process Equipment, contact a Triplex Sales Engineer today!
