Low Pressure Tire & Wheel Cleaner Procon Pump Expansion Tank Issue

[RockyMountain]

Went ahead and added TWO brand new check valves. One between the pump and the pressure switch. Another just below the solenoids. As suspected, no change. The pressure drops from 60 to 40 over and over again. So this leads me back to the expansion tank. OR, could a small dripping leak cause the pressure drop that from 60 to 40 PSI in less than 20 seconds?? Haven't readily found one, but there could be one under the tank where it's hard to see.

 

[2Biz]

You could save yourself a lot of headache trying to troubleshoot and fix your old, outdated system and control your pump with the IDX MX-8 controller like suggested earlier. You could eliminate the expansion tank, the pressure switch, and having the system pressurized all the time. With the IDX, the pump ONLY runs when the rotary switch calls for PS. Surely you have a terminal block you can wire into? You don’t have to rewire your solenoids. For a 4 bay, you only need 5 wires for input to the IDX, 4 hot 24v wires (one from each bay) and one common. Then interrupt the 120v hot wire powering the motor. (120v input and output on IDX, its just a relay)…Simple...And effective. You're going to spend more money throwing parts blindly at what you have.

Do you know the P/N for the Fluid O Tech you ended up with? Some of them have a Pressure adjustable bypassing valve built in. Some do not have this. If you have one that DOES NOT have the built in regulator, you’ll need an external regulator like Randy suggested. Then you would bypass back to the tank.

 

[2Biz]

Another option, you could ditch that whole system and put in a flojet. It basically will do the same thing as what you have with a whole lot less moving parts....

 

[MEP001]

It's not the expansion tank.

The check valve can be anywhere between the pressure switch and the vat.

 

[RockyMountain]

Do you know the P/N for the Fluid O Tech you ended up with? Some of them have a Pressure adjustable bypassing valve built in. Some do not have this. If you have one that DOES NOT have the built in regulator, you’ll need an external regulator like Randy suggested. Then you would bypass back to the tank.

Yes it does have a pressure adjusting bypassing valve. The paperwork says its factory set and not to adjust it...

 

[2Biz]

I have a PO301 on my SFR system and a PO401 on my TriFoam system that are both adjustable. On both systems, the instructions said to adjust the pressure to what is desired. Although the PO301 on the SFR is a booster pump for the membrane. The instructions said to adjust it to get 190psi which I did. I run the PO401 for the TF @ 75 psi. Neither one has fluctuated since the day they were set about 4 years ago. The TF has a gage tee'd in right at the pump so you can see the pressure.

Does your expansion tank have a tire valve to check pressure on it? Its usually on the bottom. You're supposed to have as much air pressure against the bladder as the system pressure your running, so its something to check. Even if the bladder is bad, I don't think that is your problem. When you have PS selected and running, what is the system pressure? And are you sure you don't have a solenoid leaking by? Seems like a very touchy setup?

I just found this on Fluid o techs website. It really doesn't make much sense? It says you "Must Not Operate as a Flow Regulator, but then IF YOU DO?!!!!!! Mine has worked fine for 4 years.....

Link: http://www.fluidotech.com/Contents/... rotary vane pumps PO-MO-CO series manual.pdf

The bypass valve is a relief valve and must not be used as a flow regulator. If used as a flow regulator, the water in excess will recirculate inside the pump heating and accelerating the deposit of limestone on the pump components. The maximum differential pressure should be at least 3 bar (43 psi) lower than the bypass valve setting in order to avoid operation with the bypass valve open. The maximum differential pressure must not exceed 16 bar (230 psi).

 

[RockyMountain]

Update

Another option, you could ditch that whole system and put in a flojet. It basically will do the same thing as what you have with a whole lot less moving parts....

Just to finish off this topic, I went ahead and installed a flojet. It was pretty easy and not too expensive, so thanks for the suggestion!

Under further investigation, the issue was not with check valves or anything else. It was the pressure tank. The tank was totally full of tire and wheel cleaner and with the non-functioning bladder, would counteract causing a slow pressure loss resulting in the pressure switch cycling.

Anyway- thanks for the tips and I'm glad all is working well now!

 

[MEP001]

The check valve had to have been leaking back some or it wouldn't have kicked back on, but with the tank completely full of liquid it would have taken just the tiniest bit of backflow to cycle the pressure switch, whereas with the tank working properly it might have taken hours.

FWIW, I've been running FloJets with no sort of control and have never had an issue with losing chemical from a stuck solenoid, but adding something to keep the pump from running if no one is using it is cheap insurance.

 

[mjwalsh]

2Biz ---- 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...

Mep ---- 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!

My comment ---- Just to add to the already teenzy bit sidetracked discussion ... those of us who have the stainless steel button-led (nonrotary) style of coin boxes don't have the delay issue problem. So the nifty relay solution could be a better fit for those of us. We just hope that the distribution board required is as least as durable & reliable as the rotary switch style of coin box. I know ... I know ... Rocky Mountain probably has the rotary switch but you never know he & others may be considering the other style down the road. Now if the forum can only make our colors glow & blink

mike walsh www.kingkoin.com

 

[MEP001]

I wouldn't suggest to someone with minimal knowledge of car wash wiring to use relays instead of a controller when wiring the controller is so much simpler.

 

[2Biz]

2Biz ---- 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...

Mike....I think I have Relays figured out! The MX8 might be a little easier to incorporate for some.... I've also been thinking about installing the MX8 on all the LP functions to work with my Washer Fluid Injection System. Switch spinners wreak havoc on more than just motors!

 

[Robert2181]

To solve the problem, just use a time delayed relay. It can be programmed from 2 seconds up to 120 seconds. The only way anything turns on they have to stay on the switch selection for that amount of time.