Do Your Actuators Need Structural Supports?

By Bryce Bunting | May 20, 2015

I visited a new customer recently who had several large diameter (18″) Knife Gate Valves which were “hanging up”. The valves, which were installed in a vertical pipe on top of large silos, were getting stuck in the closed position. The customer had re-packed the valves on a few occasions over the past 2 years.

Our question was, “Have the people you purchased these valves from been to look at them and if so, what did they tell you was the problem?”   The customer responded, “We were told we needed larger actuators.”

In truth, the larger actuators would not have helped. The problem, which was immediately apparent, was the weight of the unsupported actuators were applying a side load on the gates and “pinching” them against the valve body.

We recommended the actuators be supported and my suspicion is this will alleviate any future issues!   Often, when purchasing large diameter valves, particularly if the valves are in a vertical pipe, customers overlook the need to support the weight of the actuators.   This can cause 2 potential issues:

  1. Seizure (as in the case above)
  2. Premature Stem/Packing Leakage

The next time you experience one of the above issues on a large diameter valve, check your actuator to see if the weight is properly supported.   This can help save some maintenance dollars and headaches!

If you have any application questions or valve problems you would like help with, feel free to email me or phone me at 912-764-7028.

Take Care and hope everyone has a safe and fun Summer of the above headaches!