Help re-plumbing an air compressor.

I assume you have one that turns off when pressure has reached its set point? There should be a pressure switch on the tank.

you have an inlet and a outlet on the compressor.. there should be a arrow to mark the direction that compressor turns. If you are not sure, start it up so see which way the motor turns.

The inlet should have some kind of filter on it. if you put your figure over what you think is the inlet and then hand spin the pump in the correct direction, it should create vacuum (inlet) and the other should create pressure (outlet) Outlet most likely goes to the tank or into the pressure switch which goes to the tank.

Inlet needs a filter on it.

Etc..

Jamie

_compressor_parts.jpg

Seems like it is now called Sanborn, the compressor break down should be this one.

Thanks for the picture, wish it had little better detail. I'll study it a while, my dad modified it with a third gauge, which makes things different, but if I need to, I'll go back to original and work from there.

Thanks, Mikek

Yes, it is in place.

Now that you have sent the picture you probably see the the two tubing connections where 81 and 82 attach. and the air intake on the opposite side.

Ya, that's no problem, easy to tell the inlet from the out. But it still has two connections to the compressor besides the intake.

Thanks much, Mikek

I have powered the motor and I find both of the connections on the compressor have air pumped out. I think the center, larger fitting is the main outlet to fill the tank. I don't understand the second and the drawing doesn't help, because where it goes, I don't see anything for it to attach to. There's nothing behind the pressure switch as shown. Mikek

After some investigation, I think I have a handle on it. It has become clear parts have been changed. I probably need to buy some new parts.

I found this picture:

Which show where the tubes land. But there is no landing for the small tube.

And then I looked up the pressure switch.

This shows where the second smaller tube will land.

Thanks, Mikek

Is there a way to test that the over-pressure pressure release mechanism is not seized/corroded shut and a bomb in the making?

I need to purchase a new pressure regulator, the one on it is not the correct type. The unit has on over pressure valve. After $50 is removed from my wallet it will work as designed. This is actually boat related. I acquired ownership of a pontoon platform. One corner is low in the water, I started pumping air into the pontoon yesterday with a small air compressor and didn't see much movement, so I decided to get out this bigger compressor and started trying to make it work. This morning, using the small air compressor, I saw bubbles that I missed yesterday. There is a 4" x 7" plate at the front of one pontoon that leaks. Today I will remove the plate and pump the water out. The goal is to get it out of the water and home. Thanks, Mikek

The smaller tube is probably for the head pressure relief. When the pressure switch turns off, it presses a pin on a small valve which relieves the pressure in the compressor so it can restart without overloading or stalling the motor.

It is called an unloader.

The standard scheme is there is a check valve at the tank. The pressure switch has two ports, one to sense, and the other to relieve pressure in the compressor line so the compressor doesn't stall the motor. The small port on the compressor head would be this connection. So, if you don't have a relieving-type pressure switch, there is no place to connect the relief port. But, a relieving pressure switch is a REALLY good idea, it makes the motor's job a lot easier. When it is working right, you will get a big PFFFT every time the switch turns the compressor off.If it keeps hissing, then the check valve is gummed up or jammed.

Jon

Ahhh, that's making sense, I could not understand why there were two inputs to the pressure switch. Now I understand. Jon has mentioned a check valve, where does this go in the pneumatic circuit?

Hi Jon, Where does the check valve go in the pneumatic circuit?

The pressure

Looks like I'll be ordering a new pressure regulator and check valve. I need to check the diagram and see where the check valve is supposed to be, I don't think there is one. Thanks, Mikek

There must be a check valve or the unloader would empty the tank. It is usually located in the inlet to the tank. The compressor output goes to a T connector then to the check valve. The center of the T goes to the unloader. The pressure switch connects to the tank directly.

Sometimes all this is integrated into the pressure switch.

Generally, it is part of the actual fitting in the tank wall, in the discharge line from the compressor.

If it looks like somebody has removed the check valve, then you want to put one back in. It is possible there never was a check valve, and the motor is strong enough to start the compressor under full tank pressure. Sometimes people pull the check valve because it is sticking part-way open and leaking through the unloader.

Jon

I'm still having a problem. I ordered a new pressure switch,

I have plumbed and wired it. As I said before, the compressor has two outlets, one 3/8" and a smaller one 1/4". The larger I connected to the tank, the smaller goes to the unloader on the pressure switch. The motor will start and then shortly the circuit breaker pops. The air intake does has air coming out in puffs. My next step will be opening the unloader tube to see if the compressor will keep running. ( I think i might) but I don't know what that means. I'll also change outlets, maybe I just have a weak breaker, but I doubt it. Later today, I'll take some pictures, maybe someone can see what I've done wrong.

Thanks for you suggestions, Mikek

Here's a picture of my plumbing job,

I did unhook the small tube going to the unloader and the compressor will run fine. It does not have the air puffing out of the air intake as before with the unloader tube connected. I doesn't fill up the tank either, I suspect because all the air is coming out the unloader tube. Any ideas? Thanks, Mikek

Where is the check valve? How many connections does the tank have? Where does the pressure switch connect to the tank?

Hi all, My dad gave me an air compressor many years ago, at some point, one of the tubes from the compressor to the tank broke. I had another so, I ignored it. It has sat for years and parts have scattered. It seems like this would be obvious, but I don't know to put this back together. I find one open male connection going to the tank and two male connections on the compressor, one larger than the other. The shut off switch and the pop off valve are intact as are a valve on the tank and a valve to adjust output pressure. I just can't make sense of two connections to the compressor and one to the tank. Any Ideas?

Sanford Manufacturing Model 104A200-22

22 Gallon Tank 2 hp motor

Thanks, Mikek

Just go buy a new one, that is a small air compressor - not worth bothering with

Shaun