If you’ve been following along with our blog, you can see that we’re big on Waukesha’s line of Universal Positive Displacement Pumps. Known as the “Can-Do” pump in the sanitary process space, Universal Pumps are the work horse of many sanitary process applications. And because they’re such an important part of so many manufacturing processes, it is equally important that Waukesha Universal Positive Displacement Pumps are properly maintained. In this post, we’ll provide a brief overview of the regular preventative maintenance you should be doing weekly, monthly, and quarterly to keep your Universal Pumps in top shape.
Every week, there are a few simple things you should be doing to keep your pumps running.
Start by checking the gear case oil level and for any evidence of contaminants or leaks. Oil can leak from the gear case cover, oil seal, or gear case rear oil seal. If you’re oil level is low, add some (check the how much in the manual here!). If it appears it that your gear case oil is contaminated, drain the gear case, clean thoroughly, and add new oil. If you find an oil leak, replace the oil seals and/or replace the oil plug.
Every week, you also want to check for the start of seal failure. Catching this early can help you hedge off a huge problem down the road. When detected early, simply replacing an o-ring or seal face can save you a lot of time and product down the road. Inspecting seal faces can also help you identify applications where material is building up, a leading cause of seal failure. Simply cleaning this build up or installing a flush can prevent leakage and even over torquing down the road.
It’s also a good idea to do a general inspection of the pump once a week. Is the gear case hot? Vibrating? Is flush fluid leaking? Making an unfamiliar sound? These can all be early signs of a potentially bigger problem. Keeping an eye on your process can help you hedge off problems before they cause significant down time.
In addition to the above, we recommend checking the clean out plugs for excess grease monthly. This is something that happens with normal operation.
Also, if you are running under difficult operating conditions or an abrasive product, you may want to consider a deeper dive on some of our weekly checks. If you’re handling an abrasive product and you know your seals have a history of failing every 6-8 weeks, it’s a good idea to pull the pump from service, remove the body, and inspect the seals. Or better yet, consider a Universal 3 pump so you can inspect the seal without having to remove the pump body.
Once a quarter, we strongly encourage users to do a more thorough inspection of your Positive Displacement Pump. To start, remove the pump body and check the grease seals. These can often be worn or can cause wear to the pump shafts. If you see this, replace the grease seal and make sure they are properly lubricated.
We also want to circle back and think about our oil seals. While it can be difficult to inspect, if we see oil coming from our grease cleanouts or consistently losing oil, it’s a safe bet that we need to replace the rear oil seal.
On the fluid end, we want to do a quick check of our rotor tips and hubs. Tip to tip contact or uneven rotor tip to rotor tip clearances can be a sign that something went through your pump. If you see this, it may be time to replace the shafts, install strainers (always a good practice) and possibly replace the gears.
If we see contact between the rotor tip and rotor hub, this may be a sign of loose rotor nuts, Belleville washers being installed incorrectly, or bearing failure. To remedy this, we want to make sure the rotor torque nuts on the Universal 2 and Universal 3 are installed correctly and verify the back face clearances are the same on the upper and lower rotor. This prevents rotor crossover contact.
While looking at the rotors, we should also check for worn/damaged shaft keyways, worn rotor hubs, and sharp edges on the shaft shoulders. These can all be signs of loose rotor nuts, uneven back face clearances, or improper installation of the rotors (things like slamming the rotor against the shaft shoulder or installing Belleville-style washers backwards). If you find any of these issues, you may want to consider replacing the rotors and shafts or re-shimming the front bearings to maintain proper back face clearances.
Quarterly, we should also check for gear backlash and any axial or radial movement in the bearings. To do this, start by removing the pump body. Then, check the bearings. If you can detect movement of either shaft at the interface of the shaft and the grease seal, the bearings are failing and should be replaced. You can detect movement by hand loading the rotor end of the shaft with about 30 lbs. of force. We call this the handshake test- simply give each shaft a strong handshake.
Bearings fail from lack of lubricant, high overload, or water or product contamination. If your bearings are failing often, you will want to relubricate more frequently or talk to a Triplex Sales Engineer about ways to reduce hydraulic load. Bearings also fail or can be contaminated by leaking product seals or over greasing if excessive grease is not removed at the clean-out plugs.
Finally, let’s check the gears one more time. If you can feel any free movement when you rotate either shaft without transmitting motion to the other shaft, it’s a sign of gear backlash. Gear backlash is usually caused by loose or worn gears. If you find gear backlash, start by retorquing the gear torque nuts. If that doesn’t solve the problem, it may be time to replace the gears.
So there is your high-level overview of Waukesha Universal Pump Preventative Maintenance. In short, weekly we want to check oil levels and keep an eye on your seals. Monthly, we want to clean out our grease plugs and take a little closer look at the pump, especially if you’re running a demanding application. Quarterly, we want to be pulling the pump body, checking our clearances and for rotor damage, as well as checking for gear or bearing failure. A summary chart of these steps can be found here.
As always, if you have any questions about your Waukesha Universal Positive Displacement Pump, contact a Triplex Sales Engineer today.