Hi, I’m Mike with Kimray. In this video I’m going
to show you how to repair a 2” Lever Operated Dump Valve.
This is a Diaphragm Balanced Dump Valve. Later in this video, we’ll look at the differences
when repairing a Piston Balanced version. Start by securing the valve in a vise.
If you have an original hub design, you will need to remove the trunnion plug,
loosen the stuffing box nut,
loosen the set screw almost completely, and use a punch to remove the shaft.
Remove the Stuffing Box Assembly from the bonnet.
Remove both square keys.
If you have other versions of this valve, you won’t need to remove the square keys,
but you may need to remove the nut and washer from the end of the shaft.
Remove the follower,
Teflon packing and packing ring from the stuffing box assembly. Keep the follower as
it is not included in the repair kit. If they didn’t come off already,
remove the gaskets from both sides of the bonnet.
If the shaft is bent, it may be necessary to cut it off, then tap the Trunnion Shaft out through
the stuffing box.
Remove the four bolts from the Bonnet and remove the Bonnet.
If it’s stuck, pry it gently with a flat head screwdriver.
Re-secure the body in the vise at a 90 degree angle.
Use a large punch to tap out the cage assembly from the bottom through the top. Be
careful to remove it in a controlled manner and not let it fall out,
which could cause damage or injury. Remove the gasket from inside the
body. make sure to fully remove any of the old gasket that may be stuck.
Secure the cage assembly in the vise. Using a wrench to hold the stem in place,
insert a punch or screwdriver into the trunnion hub eyelet to unscrew it from the cage.
Then remove the diaphragm… and the plate.
To disassemble the trunnion hub, Remove the Snap Rings.
Then remove the links and pins from the stem nut and hub. Remove the o-ring from the cage. And
the cage from the stem. Place the stem in the
vise and wrench loose the lock nut. Remove the seat disc and soft seat.
And remove the ratio plug.
At this point your valve is disassembled and you’re ready to inspect the parts.
Start by inspecting the ratio plug. With this example,
if you see an excessive amount of corrosion or erosion, it will need to be replaced.
Inspect the bottom surface of the cage. If you see an excessive amount of corrosion or erosion,
or any damage that could create a leak path between the cage and seat, discard and
replace. This one will need to be replaced. Inspect the main trunnion shaft.
If it is bent, it needs to be replaced. Next, inspect the sealing surfaces on
both sides of the bonnet for pits or other potential leak paths.
Then inspect the stem to make sure the threads are intact and the stem is not bent.
Inspect the stem nut to make sure the threads are intact and there is no severe pitting.
On the valve body, inspect the threads on the inlet and outlet to make sure they are intact.
Inspect the seat area where the gasket will sit
and check for severe washouts anywhere inside the valve.
Clean the interior and exterior to make sure it’s free of all solvents,
debris and fluids that may damage elastomers and affect o-rings and gasket seals.
Run all the parts through a parts washer.
If you don’t have one available, use a wire brush, degreaser and the appropriate PPE
to get them as clean as possible.
For this re-assembly, We’ll be using new components to walk through the process.
Place the new O-ring onto cage. With the stem upside down in the vise,
place the ratio plug onto the stem. In our newer models, the ration plug comes standard in Delrin.
Grease and assemble the new style seat from the repair kit. This replaces both the old seat disc
and seat. The new seat is reversible, effectively doubling its life span. If one side is worn,
simply flip the seat to use the other side. Thread on the lock nut, then flip the stem
assembly and re-secure it into vise. Place the cage on the stem assembly
Followed by the stem plate with the serrations facing outward.
Then attach the diaphragm. To build the trunnion hub stem
nut assembly, attach the 2 links and pins, and 4 new snap rings.
If you have this version of the hub and shaft that has one flat,
we recommend you replace it with the new style hub and shaft with double flats to reduce angular play
in the hub and shaft connection. Kimray can send you the new style hub and shaft free of charge.
Just contact Kimray customer service and have your serial numbers ready.
If you have the keyway style, you can keep that in your re-assembly.
No replacements needed unless they are damaged. Apply Loctite and thread the nut onto the stem.
Grease the o-ring,
the shoulder where the gasket will seal, and then grease the gasket.
Secure the body in the vise and insert the cage assembly with the hole facing
the same direction as the valve connection.
If needed, use a mallet until the cage seats.
The diaphragm should be flush with the machined surface.
Make sure the hub is in the correct orientation by checking that the flat on the bottom side
is in line with the pin hole when the hub is facing away from the inlet of the valve.
It would look like this if it were incorrectly oriented.
As mentioned earlier, we don’t recommend using the hub with one
flat, but if you need to use it, then this is the correct orientation-
with the flat side on the bottom when the hub is facing away from the inlet of the valve.
While holding up hub assembly, place the bonnet on the body.
For the standard assembly, the rounded side should face away from the inlet.
There can be variations, so make sure to re-assemble the way it came.
Attach the four bonnet bolts and tighten in a criss-cross pattern to avoid misalignment.
Grease the shaft and insert the thicker end into the bonnet as shown.
Make sure the flat end is down.
Slide the bushing into the trunnion plug,
add the o-ring, then grease them both.
Thread the trunnion plug into the bonnet and tighten with a wrench.
To assemble the stuffing box, start by placing the Teflon bushing on the shaft.
Grease the end of the stem and where the flat ends to reduce the risk of cutting the o-ring.
Then add the new o-ring,
being careful to not cut the o-ring on the edge of the flat. Then apply grease.
Install the o-ring around the outside of the stuffing box, then apply grease.
Slide the stuffing box onto the shaft and hand tighten. Then tighten with a wrench.
Install the new lever hub with the arm attachment slot facing away from the bonnet.
Tighten the set screw at the bottom. If your lever hub does not have a set screw on the bottom,
we recommend replacing it with the newest style lever hub to reduce angular play in the hub and
shaft connection. Kimray can send you the new style lever hub and set screw free of charge.
Just contact Kimray customer service and have your serial numbers ready.
If you have a different style shaft that has threads at the end of it,
slide on the washer and tighten the nut. Complete the assembly by attaching the lever
bar pointing the same direction as the inlet.
If you’re reusing the old-style hub assembly, installation will look a little different
starting from once you’ve inserted the cage and bolted the bonnet to the body.
Insert the shaft into the hub.
Insert the shorter square key into the keyway in the shaft. Tap into place with a punch.
Install the new gasket on the Trunnion Plug, making sure the it rests against the shoulder
of the Plug. Apply grease to the gasket and then tighten the plug with a wrench.
Then Install the Washer onto the shaft.
Install the Gasket onto the stuffing box and grease.
Thread the stuffing box onto the bonnet.
Install the Packing Ring with Teflon Packing, follower and
nut onto the Shaft.
Install the hub and the longer square key.
Tighten the set screw until snug.
This completes assembly for the diaphragm balanced dump valve.
There are only a few parts that differentiate the
piston balanced from the diaphragm balanced dump valve. We’ll look over those differences now.
Once you remove the piston assembly from the body, secure it in a vise.
Use a wrench to hold the stem in place.
Insert a punch or screwdriver into the trunnion hub eyelet to unscrew it from the cage.
Remove the piston with the O-ring and two back-ups
Then remove the cylinder from the cage. And the two o-rings from the cylinder.
Remove the piston seal retainer and the o-ring Remove the oring from the cage.
Finally, remove the cage from the stem. Flip the stem over and secure it in the vise
to remove the nut, Seat disc,
And ratio plug. Inspect all the parts
for excessive amount of corrosion or erosion or any damage that could create a leak path.
Inspect the stem to make sure the threads are intact and the stem is not bent.
To reassemble, repeat this process in reverse,
greasing all of the new gaskets, o-rings and backups as they are applied.