Repairing a Stem-Guided High Pressure Control Valve can be a daunting task. The Kimray Repair School is here to help. This guide will detail how to disassemble the valve, and the next guide will detail how to repair and reassemble it.
To get started, remove the upper adjustment screw and breather plug. Then remove all the upper bonnet bolts and remove the O-ring from the upper adjustment screw. Remove the bonnet, pivot, upper spring plate, spring, and lower spring plate.
Next, unthread the diaphragm plate from the upper stem. There are two flats on the upper stem where a wrench can stabilize while the diaphragm plate is threaded. Remove the diaphragm and diaphragm plate and loosen the coupling block bolts and remove the coupling block.
After that, remove the four bolts from the yoke base and empty all the oil out of the yoke. After this, remove the upper stem, flip the yoke over, and remove the lower adjustment screw. Remove the snap ring, retainer, wiper, outside O-ring, and inside O-ring from the lower adjustment screw. Remove the stuffing box assembly from the body and mount it in a vise. Be aware that sometimes the seat will come unthreaded from the cage and stay down inside the body. If this happens, use the Kimray Seat Removal Tool to get the seat out.
Another potential issue could be the cage coming unthreaded from the stuffing box. In this case, the cage might stay in the body along with the seat. To solve this issue, just flip over the Kimray Seat Removal Tool, thread it into the cage, and remove the cage and seat all in one piece.
Next, remove the seat from the cage. To make things easier, stick a screwdriver through the cage to hold it still while loosening the seat. Then use the screwdriver to loosen the cage and take tension off the stem. Only loosen it a couple of rotations to keep the threads engaged, and then remove the O-ring from the seat. Now take the cage all the way off. Remove the spring, follower, and packing. Also, remove the O-ring on the outside of the stuffing box.
Next, take the stuffing box out of the vise, turn it over, and use a pair of snap ring pliers to remove the snap ring. Also remove the retainer and the felt wiper. After that, remove the diaphragm nut from the diaphragm plate. To do so, take the custom Kimray wrench, put it on the diaphragm nut, and run it in your vice.
If you need more information about your high pressure control valve, or if you run into an issue while repairing any Kimray product, contact your local Kimray store or authorized distributor. We’ll be happy to help.