I repack my own control valves, but the packing does not last. What is going on?
We suggest that you only use original manufacturer’s packing, especially when you are replacing V-ring type teflon packing. It is sometimes necessary to tighten the packing while the valve is in service. If the packing is tightened too much, the teflon is compacted and will not “spring back” to fill the packing area. DO NOT use grafoil or rope packing in the place of teflon v-ring packing-it causes excess drag on the stem, and will require more actuator force to open or close the valve. Another cause of accelerated packing failure is excessive cycling-the valve opens and closes too frequently. This may be caused by over- or under-sizing the valve, or faulty positioner set-up, leading to “hunting”. For help in determining the cause, give us a call (800-528-6639).
