High Pressure Rinse and Spot Free Rinse Contaminated With Another Chemical

[mparker1975]

Hello everyone. I am new to the forum and just completed my first year in the car wash industry.

At one of our car washes we have four self serv bays. In all four bays the rinse water is mixing with another product (smells like it could be pre soak). It appears the problem may be a check valve in the attic feeding one of the bays. I removed the rinse hoses at the outlet side of the pumps and I do not see any mixing there. If it is Pre Soak I don't see how its mixing since it has its own pump and runs through solenoids down stairs and check valves in the attic. I guess it could be another product that runs through a pump but why am I seeing the contamination in all four bays.

Any help is greatly appreciated.

 

[MEP001]

The high-pressure lines are probably bad and trapping some of the soap from that cycle and releasing it with the rinse. There's no way anything else can get into the lines from a bad check valve and contaminate the rinse cycle. If the rinse water is being drawn from a gravity-feed tank, that might have something backing up into it, but if it's fed by city pressure, that narrows your problem down to the lines to the bays.

 

[cantbreak80]

A leaking weep system check valve might be the problem.

Weep water is connected to city water supply. If a check valve is leaking, high pressure soap is flowing backwards, pushing open the weep solenoid and “injecting” soap/wax into the car wash’s water supply. When the rinse water tank valve opens, the “contamination” fills the rinse water tank…thus, all bays are contaminated.

If your SFR system is contaminated, the entire water supply system is contaminated...including the softener and heater systems. Close the main weep system valve. Then, regenerate the softener, drain the SFR and rinse tanks and allow the systems to refill.

 

[mparker1975]

The high-pressure lines are probably bad and trapping some of the soap from that cycle and releasing it with the rinse. There's no way anything else can get into the lines from a bad check valve and contaminate the rinse cycle. If the rinse water is being drawn from a gravity-feed tank, that might have something backing up into it, but if it's fed by city pressure, that narrows your problem down to the lines to the bays.

When you say the high-pressure lines are bad do you mean the soap is absorbing on the inside of the hoses or there is a low area trapping the soap? We had all four bays shut down today with very little soap running through the lines. We removed every check valve on on four pumps, we found a few bad ones but they did not solve the problem. From what you're saying, a bad check valve would not cause the problem, correct?

The problem is mixing in all four bays and I am at a loss. Any more suggestions?

 

[mparker1975]

FYI. All products meet at a manifold for each bay in the attic. Each product has a check valve.

 

[cantbreak80]

Did you inspect those weep system check valves?

 

[mparker1975]

Did you inspect those weep system check valves?

I did not since the weep system has a main shut off valve off the feed and a solenoid and another ball valve at each pump.

Could it still be backing up there? I will definitely check there if you think I should.

Thank you for your help!

 

[cleaning up mud]

what fixed it?

 

[cantbreak80]

I did not since the weep system has a main shut off valve off the feed and a solenoid and another ball valve at each pump.

Could it still be backing up there? I will definitely check there if you think I should.

Thank you for your help!

If those manual valves are truly closed...then my diagnosis is incorrect.
But, since you found other faulty check valves, it's an easy inspection. Remove the weep supply line from the check valve and turn the pump on.

 

[mparker1975]

what fixed it?

We are still having the problem. I am going to regenerate the soft water system tomorrow and drain the sfr tanks.

 

[mparker1975]

what fixed it?

After further thought and I feel stupid for not thinking about this but last Friday we had Culligan there checking the water softner since our RO membranes went bad after one year. They noticed that a bypass valve was open at the softner. We did not notice the problem until this Monday but it makes since because we were not having this problem until they closed the bypass to the softner. We changed the membranes on Friday and the tds tested at a 6 and the hardness was at a 1. Maybe the rinse water is not mixing with another product but the rinse water is foaming and spotting badly. Why the bypass valve was open is beyond me but somebody must of opened for a reason.

Do you think the problem is at the softner?

 

[mparker1975]

If those manual valves are truly closed...then my diagnosis is incorrect.
But, since you found other faulty check valves, it's an easy inspection. Remove the weep supply line from the check valve and turn the pump on.

After further thought and I feel stupid for not thinking about this but last Friday we had Culligan there checking the water softner since our RO membranes went bad after one year. They noticed that a bypass valve was open at the softner. We did not notice the problem with the rinse water until this Monday but we were not having this problem until they closed the bypass. We changed the membranes on Friday and the tds tested at a 6 and the hardness was at a 1. Maybe the rinse water is not mixing with another product but the rinse water is foaming and spotting badly. Why the bypass valve was open is beyond me but somebody must of opened for a reason.

Do you think the problem is at the softner?

 

[cantbreak80]

Maybe the previous owner had a problem with the weep system check valves? And, the softener is full of soap? And, rather than fixing it, he just bypassed the softener?

Try bypassing the softener and the boiler, drain and refill the rinse tank and see if the problem goes away?

 

[Randy]

A solenoid valve is designed to stop the flow in one direction only. If you pressurize the downstream side of the solenoid it is possible to back feed the system. If you have a failed check valve you’ll get a backflow past the solenoid valve. Check all the check valves up in the attic. If you’re using a brass check valve replace them with a stainless check like this one from Kleen-Rite http://www.kleen-ritecorp.com/p-1764-fluid-controls-check-valve-14-viton-ss-hp.aspx Not too long ago I had a problem like what you’re having and it was a bad valve on the Pre-soak system out on the boom that would only leak on low pressure on high pressure it would hold.

 

[mparker1975]

Maybe the previous owner had a problem with the weep system check valves? And, the softener is full of soap? And, rather than fixing it, he just bypassed the softener?

Try bypassing the softener and the boiler, drain and refill the rinse tank and see if the problem goes away?

Great point! I will definitely try your recommendations in the morning. Thanks

 

[mparker1975]

A solenoid valve is designed to stop the flow in one direction only. If you pressurize the downstream side of the solenoid it is possible to back feed the system. If you have a failed check valve you’ll get a backflow past the solenoid valve. Check all the check valves up in the attic. If you’re using a brass check valve replace them with a stainless check like this one from Kleen-Rite http://www.kleen-ritecorp.com/p-1764-fluid-controls-check-valve-14-viton-ss-hp.aspx Not too long ago I had a problem like what you’re having and it was a bad valve on the Pre-soak system out on the boom that would only leak on low pressure on high pressure it would hold.

Thank you! I will definitely check them in the morning and let you know.

 

[MEP001]

Does the spot-free rinse also tee in at the top of the bay, or does it tee in at the pump? If it's at the pump, it makes the most sense that it's the high-pressure lines. If you run a bay on soap and then rinse, you see suds, right? Try running it on soap, then wax until it comes through, then rinse and see if you still see suds.


The bypass on the softener is not the culprit. The problem has likely been there for a while, but the hard water was not letting you see the foaming. Closing the valve let soft water through the system, and it suds more easily.

If you have the supply ball valve to the weep closed, the weep system or its check valves is not the culprit.

 

[cantbreak80]

I think Mep001 nailed it.

The car wash has been operating on hard water for over a year.(?)
The change to soft water has made the soap-saturated hose issue more visible.

The “wax before rinse” test will verify his analysis.

Good call Mep001!

The good news is that after you replace the pump-to-bay hoses, you should be able to dial back your soap dilution. Improved cleaning AND lower operating expenses!

 

[mparker1975]

I think Mep001 nailed it.

The car wash has been operating on hard water for over a year.(?)
The change to soft water has made the soap-saturated hose issue more visible.

The “wax before rinse” test will verify his analysis.

Good call Mep001!

The good news is that after you replace the pump-to-bay hoses, you should be able to dial back your soap dilution. Improved cleaning AND lower operating expenses!

Can you explain the wax before rinse test?

So you guys think all the high pressure hoses are bad and need to be replaced?

 

[cantbreak80]

Run the bay on Soap
Switch to Wax for 10-15 seconds
Switch to Rinse

Once the wax clears the line, does the rinse water still have suds? If so, the hoses are old and absorbing soap.
It takes a long time for the rinse water to clear the absorbed soap...especially since it's now soft water.

Introducing Wax before rinse basically "kills" the soap suds in the absorbed hose.