Dia-Vac® Diaphragm Pump Repair Instructions (R, M Series)

Hi, I’m Chris. Welcome to ADI’s YouTube channel.

Today we’re going to go over the proper installation of our diaphragm pump repair kit. This is our 11005 diaphragm pump repair kit. It’s a Teflon EPDM kit. It’s our most common diaphragm. Really, any of the other materials, whether it be all Teflon, Teflon/Viton, or Viton, you can follow along with the same sort of instructions and you’ll get the same result.

Also, any of our pumps that use what we call our standard head right here, this square head, whether it’s our mini Dia-Vac® pump as you can see right here, or an explosion proof with a different motor, anything that’s got this sort of a head… there may be a different shape in the diaphragm. For example, the mini uses a round. But you can see it’s still Teflon coated and EPDM, and really the instructions are the same for that one as well.

What we’ll need in order to do this change-out properly are a few tools. First of all, we’re going to need a 5/32 Allen key. Then we’re going to need a 3/16 Allen key. We’ll need a 3/16 torque wrench, set to 110 inch pounds. A 5/32 torque wrench that’s set to 70 inch pounds. And a bottle of Loctite medium strength 242 or equivalent.

The first thing that we’re going to want to do, of course, on the head is remove the four head bolts. So we’ll grab our 3/16 Allen key, and we’ll go ahead, break the seal on that.

Okay. Now that our four head bolts are loose, we’ll go ahead and remove them, and just place them somewhere where you’ll find them later. Then now our head is able to be taken off the pump.

You can see here the diaphragm. Where you would normally find wear is along this diaphragm. Obviously, this diaphragm is still good. You may even see some of the EPDMs start to impede if the chemical has actually attacked the diaphragm.

In any case, this is the inside of our pump head. This is the valve body. What’s nice about this pump head is because the valve body is inserted and married into this part, we can position this in any position, and as long as this valve body is inserted, it will always flow in the direction of the gas.

What we’ll do is we’ll put the head aside for now, and we’ll take a look at the diaphragm. Now you can see this diaphragm is okay, but typically a worn diaphragm, you’ll start to see some cracks around here. You may see some of the EPDM flake up depending on how long it’s been in service.

What we want to do is grab our 5/32 Allen key. Insert it into the diaphragm screw. Now that it’s loose, we’ll go ahead and remove the complete diaphragm assembly. What that diaphragm assembly is made up is of a screw, a Teflon washer seal, a diaphragm plate, and then of course the diaphragm. The first thing we’re going to want to do is pull off the old diaphragm. We’ll discard it. Then we’ll pull the head out and remove the Teflon washer.

Now we’ve got these parts, and we’ll go ahead and we’ll go into our kit. I’ll go ahead and just pull out the washer for now. We’ll take our screw and just thread it through like so. Then we’ll take our diaphragm plate, place the screw in there, take the new diaphragm, place it through the center hole, and now I’ve got a new diaphragm assembly. Next part, we’ll grab our Loctite. One drop of Loctite on the thread. Place it over the connecting rod. 5/32 Allen, and then we’ll begin to tighten that down.

We’ll go ahead and grab the 5/32 torque wrench at 70 inch pounds. Make sure it’s nice and tight. Now our diaphragm is good. Then what we need to do is change out the inner components of the head, which includes the gasket and the two valve discs. Again, we’ll grab our 5/32 Allen key, and we’ll want to just unscrew these top valve body screws here on top of the head. Now it’s really important for me and my left hand to keep it underneath the head here. That prevents the valve body from falling out once these are loose. So we keep pressure under there, we hold it, and then nothing gets lost. Our valve body drops right out. We’ll put our head to the side.

Inside here we can see the gasket. We can see the discs. These may wear before the diaphragm, but most people like to just go ahead and change out all the parts at one time while the head’s open. We’ll go ahead and take out those valve discs, discard them. Then we’ll take the old gasket, discard that. We’ll go back to our repair kit, and we’ll pull out the gasket. When you look at the valve body, you can see that one of the posts has two splices on the end of it. That’s the one that you’re going to want to put with the bigger hole, but it can only go in one direction. Then we’ll take our new valve discs, place them in. They should have a little bit of movement to them.

Take care to keep it nice and flat, and don’t allow the discs to get up on the posts. What can happen is you put the head on it, and then it can become pinched. Now we’ll take our head, and you can see that this is the one with the posts. Lines up with this one with posts. We’ll go ahead, keeping it flat the whole time, we’ll marry those parts together. Always putting pressure underneath the head to hold it in place, and then we’ll take our valve screws and place them on top. Again, using our 5/32 Allen key, we’ll go ahead, all the while keeping this tight. We’ll get that, give it one turn, then give it one turn, so it’s nice and tight. Now I can release it. It won’t fall out.

Now, we’ll orient the head onto the pump. The way that it’s going to go from the factory is from right to left, but again, this pump can be in any position, and it will always flow in the direction of the arrows.

Let’s go ahead and line it up there. We’ll go back to our original head bolts. Put those on like so. Then we’ll grab our 3/16 Allen key and go ahead and get these started. We’re almost there. Now our head’s installed correctly. In order to ensure that we don’t have any leaks, we don’t have any performance issues, and have a nice good seal, I want to make sure that we torque down our screws. Valve body screws are going to be set to 70 inch pounds. Then we’ll grab our 3/16 torque wrench, set for 110 inch pounds, and now we’ve got the diaphragm back installed into the pump.

Everything should be working good. The way you’re going to want to test it, on a general purpose motor, the electrical component is in the back here. You’re going to want to wire it for 110 or 220. Wiring instructions are located on all the motors. You’re going to want to plug it in, and then you’re going to want to check out which eccentric size you have, which you can find at our website at airdimensions.com. It’ll be on the very front of the model number. Depending on the eccentric size, you’ll get different flows and pressures.

In this case, we have an R-221. Once we do our install of our diaphragm, we want to go ahead and test the pump and make sure that we didn’t make any mistakes and that it’s working properly. We’ll do that by adding power to it, and then we’ll put a pressure gauge on it.

This pump should be around 50 PSIG on the discharge. The inlet should get about 22 inches of mercury, and the flow should be approximately 26 liters per minute. If your pump is getting all those three numbers, then you know you’ve done the install correctly and the pump is ready to go and be installed in the system.