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One Simple Thing You Can Do To Extend The Life Of Your Control Valve

June 8, 2017

If you see your control valve leaking around the packing box or valve stem, you may be able to fix the leak using the instruction contained in this video.

Jerry Butz, Director of Engineering, will walk you through this one simple procedure that can extend the life of your control valve.

 
Valve packing is a component in a valve that forms pressure seal between the inside of the valve and the outside of the valve, keeping the process fluid from leaking out. Over time, the packing will wear in, relax, or loosen up with process temperature, or even seasonal ambient temperatures, and begin to leak. And any process fluid that leaks out of a valve can be costly, can be messy, it may be even harmful to health and environment. The most important thing is to catch the packing leak early and address it before it has a chance to further cause damage. In the early stages of packing failure, it may be difficult to detect the process fluid coming out of a packing box unless you’re very attentive in keeping an eye on the valve. But the leak is only going to worsen.

Here we are at a typical valve location. I’m going to show you how to detect and correct a packing leak. Here, we see water weeping out around the packing and the valve stem. When you first notice this sort of leak, attempt to correct the packing leak by carefully tightening the packing nuts. I will use a 3/4″ combination wrench and tighten the packing ever so slightly. It doesn’t take much, just enough to seal the leak again. Be sure to tighten the nuts evenly and do not over-tighten, or you could interfere with the actuator’s ability to stroke the valve. When you see the leak has stopped, you’ve fixed it. Now, if you find you have to use a fair amount of torque to tighten the packing nuts, you may be at the end of the adjustment and cannot tighten the packing any further. That means it’s time to replace the packing set.

Replacing the packing in the valve would typically involve removing the valve from service and disassembling the actuator from the valve, and then separating the valve body to completely access the packing box. Although this is a fairly easy task, you should refer to your product instruction manual for step-by-step directions, or consult with your account representative with how we can take care of that for you. There are a multitude of other maintenance tasks that you can and should do with your control valves. But packing maintenance is probably the easiest and most cost effective step you can take to extend the life of your control valve. If you do nothing else with the valve, keep the packing in good health.

Automation Service has a dedicated staff of engineers who specialize in Automation Service remanufactured Fisher® control valves. If you have questions about valve maintenance, sizing or specifications, give us a call, or click the button below to request assistance.  We’re always happy to help!

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