Low Pressure Tire & Wheel Cleaner Procon Pump Expansion Tank Issue

[RockyMountain]

Our tire & wheel cleaner is distributed with a pressure switch, electric motor, procon pump and expansion tank. We also have needle valves to adjust the air.

Issue: The procon pump would not build enough pressure to turn the pressure switch off.
Solution: Replaced the procon pump. Was talked into a fluid o tech.

New Issue: The pump works great, except when everything is turned off. The pump comes on and builds pressure. The pressure switch (brand new also) turns the motor off. The pressure drops and the pump comes back on. This happens over and over. I assumed there was a leak in a solenoids. Not the case. I have even plugged the output line before the check valve. There is absolutely no chemical going anywhere, yet the pump and pressure switch continue to cycle on and off. I assume the pressure is being lost either back through the pump or could it be a failing expansion tank? I checked the pressure on the tank and tried both increasing and decreasing it with no success. What should it be? More or less or the same as the chemical pressure?

I tried to attach a picture but the forum website and I weren't getting along.

Any advice would be much appreciated.

 

[RockyMountain]

Procon Pump Expansion Tank Tire & Wheel Low Pressure Delivery Issue

Our tire & wheel cleaner is distributed with a pressure switch, electric motor, procon pump and expansion tank. We also have needle valves to adjust the air.

Issue: The procon pump would not build enough pressure to turn the pressure switch off.
Solution: Replaced the procon pump. Was talked into a fluid o tech.

New Issue: The pump works great, except when everything is turned off. The pump comes on and builds pressure. The pressure switch (brand new also) turns the motor off. The pressure drops and the pump comes back on. This happens over and over. I assumed there was a leak in a solenoids. Not the case. I have even plugged the output line before the check valve. There is absolutely no chemical going anywhere, yet the pump and pressure switch continue to cycle on and off. I assume the pressure is being lost either back through the pump or could it be a failing expansion tank? I checked the pressure on the tank and tried both increasing and decreasing it with no success. What should the expansion tank pressure be? More or less or the same as the chemical pressure?

I tried to attach a picture but the forum website and I weren't getting along.

Any advice would be much appreciated.

 

[Randy]

The easiest and best time you can do is eliminate the bladder tank and pressure switch and install IDX MX-8 controller, https://www.kleen-ritecorp.com/p-24000-idx-mx8-controller.aspx it takes the place of the bladder tank, pressure switch. The bladder tank set up is old school, I don’t know of any car washes around here that still use them. We use the MX-8 on all of our low pressure systems, eliminating the Flo-jet pumps.

 

[mmurra]

Randy - can you explain how that works, without the Flo-jet pump? Thanks!

 

[MEP001]

There's a check valve that traps the pressure in the system. That check valve is bad.

 

[MEP001]

The MX-8 controller is extremely simple - just run a jumper from each bay from the output that opens the solenoid to each input of the controller and wire the pump power to the controller output.

 

[RockyMountain]

Actually, as stated, I eliminated the check valve and plugged the outgoing hose. I actually plugged it by reversing the direction of the check valve and leaving the opposite end open. Not only did no liquid come through the valve, showing that it is functioning properly, the system continued to cycle on and off.

 

[RockyMountain]

I can appreciate your approach. This current system has worked great for a decade, plus. I hope it's not necessary to purchase a controller and re-wire this as the solenoids hang high on the wall and the pump unit is on the floor. Seems like unnecessary work and expense if simply replacing the expansion tank would solve the issue.

 

[Randy]

Randy - can you explain how that works, without the Flo-jet pump? Thanks!

There pretty easy to install. The MX-8 controller starts and stops the electric motor that the Procon is mounted on. We install the Procon pump lower than the tank so the pump is in flooded condition, with an 80 mesh screen on the pump inlet. We use an external regulator on the discharge of the pump with the regulator bypass line running back to tank. We set the pump discharge pressure at 110 psi by adjusting the external regulator. Wiring the MX-8 is also pretty simple. Run 110 volts to the MX-8 and 110 volts out of the MX-8 to the pump motor. On the 24 volts side jumper together all the commons on your solenoids and run a common to the MX-8. Then run a wire from each bay to the MX-8 to energize the MX-8, we have a terminal strip next to the manifold that we jumper the commons on and connect the wire from the bay to the MX-8. In 19 years I’ve been running this set up, I’ve replaced 1 pump and one regulator. The MX-8 has a 2 delay on and off, MX-9 has no delay, the MX-10 has a 1 second delay on and off.

 

[Randy]

Do you have a check valve between the pump and the expansion tank?

 

[RockyMountain]

Do you have a check valve between the pump and the expansion tank?

No it's just before the solenoids and has been that way for years.

 

[MEP001]

I can appreciate your approach. This current system has worked great for a decade, plus. I hope it's not necessary to purchase a controller and re-wire this as the solenoids hang high on the wall and the pump unit is on the floor. Seems like unnecessary work and expense if simply replacing the expansion tank would solve the issue.

Again, the problem is with the check valve. If the expansion tank was bad, it would click on and off rapidly while in use and stay off while not in use.

 

[MEP001]

You need a check valve to keep the pressure trapped in the expansion tank, otherwise it will just keep filling the tank and then draining back to the vat.

This and your other thread on the exact same matter need to be combined to avoid confusion.

 

[2Biz]

I will add something to Randy's suggestion, which I believe is the best way to go with the IDX MX-8.... I have a fluid o tech on my tri-foam that has a bypassing regulator built into the pump. No need for the external regulator. I have mine set at 75psi and the pressure has never fluctuated in 4 years.

I'll throw this out there too. You can do the same thing with relays, but you won't have the 2 second delay that the IDX has...
The IDX is less than a hundred bucks....A no brainer for me...

 

[MEP001]

I've used relays instead of a controller - it's a lot less expensive, but I like the idea of not having the pump kick on every time someone passes that function on the switch.

 

[2Biz]

I agree! When I'm in the ER and someone is "Switch Spinning", it makes me cringe when I hear all my pumps/motors start for a split second. Another project!

 

[RockyMountain]

How do I combine the 2 threads. Not sure how it was posted twice.

 

[I.B. Washincars]

How do I combine the 2 threads. Not sure how it was posted twice.

I just did it. It has to be done by a moderator.

 

[RockyMountain]

You need a check valve to keep the pressure trapped in the expansion tank, otherwise it will just keep filling the tank and then draining back to the vat.

The only check valve that has ever been there is the one after the pressure switch/expansion tank and right before the solenoids. Is it possible that procon pumps don't allow liquid to flow the opposite direction and fluid-o-tech pumps do?

Sounds like a check valve right after the pump and before the pressure switch and expansion tanks could be the solution.

 

[MEP001]

Procons do not prevent reverse flow. There is a check valve in there already that needs to be replaced. It can be anywhere including at the outlet of the vat.