Do I need check valve

[Dan-Ark]

Getting close to re opening my wash. having to replace most (if not all) the 1/4 poly tubes. We have air mixing with pre soak and foam brush just before the booms. I replaced the air pressure regulator for the foam brush because it was leaking and I found the old one full of sludge. The next day after testing functions in the bays, I find pink water dripping from the new regulator. it seems fluid is backing both the foam and presoak air lines. Should there be check valves on the air lines? If so do they need to be near the booms in the bay or at the pump stand. This wash is decades old and was refitted around 2006 but I am not finding any check valves on the air supplies. Maybe the air pressure just has to be set higher than the pump pressure to keep the air lines full of air?

 

[Ontario Car Wash]

You can put a check valve
most likely you did not have enough air to keep it from backing
otherwise mine is same i have a maniforld in the attic above the boom with air to presoak , tire and brush. I have check valves on all but the air. And i to would see pink in the air line or even full of liquied sometimes, i just kicked the air up and its been fine.
Good luck

 

[mac]

What you are seeing is common. The mixing air to make bubbles has to be less than the liquid pressure or the pump will stall out. I found some cute 1/4" ones that we put on the output side of the regulator which stops it.

 

[Dan-Ark]

Thanks for the replies, it was probably not helping that I was shutting off the air when I leave since the wash is not open. I think I have all the air leaks fixed, I guess I might as well get brave and leave it on, has to happen sometime.

 

[Main Street Carwash]

Not enough air pressure or too much chemical pressure. Usually setting the chemical pressure a little above air pressure (10-20%) is a good starting point. Backflowing chemical into your air pressure regulators is hard on them so try to avoid doing it too much.

 

[2Biz]

Ideally you want the regulator ahead of the solenoid. My old setup had the air regulators after the solenoids and I had the same issues. With the regulator ahead of the solenoid, it was a two fold fix....I used to have 4 regulators for each FB and PS. I now only have one air regulator for all 4 Fb and one air regulator for all 4 PS...Win!!! Win!!!

I guess there is another Win! Win!....There is no need for CV's with this setup....I only have 8 CV's in the whole CW....4 for SFR and 4 for weep....Put on your thinking caps!

 

[Dan-Ark]

My regulators are ahead of the solenoid blocks, so at least I don't have to redo those. I think the problem is with one of the soleoids open, it can still push back to the regulator. I did just adjust one of my brushes so I was getting nice lather out of it, I have not checked to see if the air is overpowering the fluid since, maybe I just had things so far out of kelter it was causing the problem, that and shutting off the air every day when I leave.

 

[Main Street Carwash]

What type of pumps are you using for the chemical?

 

[2Biz]

I think the problem is with one of the soleoids open, it can still push back to the regulator.

That shouldn't happen as long as you have a positive air flow through the regulator. If you have leaky solenoids, they should be replaced. If you are running flojets, you might want to put solenoids on the air supply to the flojets to eliminate issues with leaky or stuck open chemical solenoids. It seems this always happens when you are not there and you end up wasting a whole 5 gallons or more of chemical!! The air shutoff solenoids eliminate this and give you warning as to when something is wrong down-stream.

BTW, if you are running flojets, when you are there and no one is using the bays, do you hear the flojet/flojets cycle even though they are not in use? If they do, that's the indicator that you have chemical solenoid issues that need fixed. They should not leak by.

 

[Dan-Ark]

What type of pumps are you using for the chemical?

Flojet. Ive got LOTS of flojets in my wash, maybe 12 or more.

 

[Dan-Ark]

No, the flojets don't pump unless something is on, (then some work and some dont still going through those function by function). I'm going to make sure I turn the air on before anything else gets turned on and keep an eye on it.

 

[Main Street Carwash]

Flojet pumps work off of air pressure so if the air is off, they should not deliver any chemical. If you regulate the air pressure going to the flojet, it will dictate the output pressure of the pump. This is a better method than feeding the pump higher air pressure and regulating the output of the pump as flojet pumps generally don't like much greater than about 90 psi input pressure. The pumps will live a lot longer if air inlet pressure is 90 psi or less and water is kept out of the air side of the pump. Make sure they are mounted with the connections facing down.

 

[Dan-Ark]

My flojets each have a regulator on the air feed. I have no adjustment after the pump, wait, that's not true because there are flow adjustment screws on the solenoid manifold for each solenoid valve. For foam and presoak, do I need to set the pressure higher on the pump or on the air or does it vary. I noticed when I turned both down around 50psi, my foam brush made great lathery foam so maybe I'm getting close.

 

[Main Street Carwash]

Keep the air a little below the chemical. Maybe try 50 chemical and 40 air. If the air is too high, it will spurt and sputter out inconsistently. If the chemical is too high, it won't foam as well and be watery. The needle valves after the solenoids are for fine tuning to compensate for differences between the bays.

 

[Main Street Carwash]

Also, adjust your chemical and air pressures to the manifolds with all bays running at once to make sure the pressures are high enough to compensate for the pressure drop of all bays running at once because hopefully that will be the case once you open. A lot of people find 30 psi chemical and 25 psi air to be acceptable or even ideal for them. I always seem to get best results in the 40 to 60 psi range. I guess about a 20% lower air pressure is about right regardless of actual pressures. FWIW, neither of my car washes have check valves for low pressure functions except at the high pressure boom to prevent the high pressure from backflowing into the low pressure lines. Clear poly tubing is good for a quick visual of whether this is happening. If a line is clear and not pink or green or whatever color the chemical is, it's usually due to a faulty check valve at the high pressure boom. As long as the air pressure on your low pressure functions is just below the chemical pressure, it should not backflow chemical into the air side of the system. If this is an older wash that you are reopening, you may want to check the condition of the foam generators. The material inside (basically pot scrubbers) will deteriorate over time and start coming apart and clog up fittings and tri foam tips, etc. I had to take apart every fitting downstream of my foam generators when I redid a wash I bought because pieces of foam generator were trapped everywhere severely restricting output flow which made it impossible to adjust the foam consistency.

 

[pgrzes]

I usually turn the air off and get the chemical flow I am looking for to the bays, then start to adjust the air to get the lather that I am looking for. Start with furthest bay from equip room then when finished that turn them all on and make any small adjustments.

 

[Earl Weiss]

I usually turn the air off and get the chemical flow I am looking for to the bays, then start to adjust the air to get the lather that I am looking for. Start with furthest bay from equip room then when finished that turn them all on and make any small adjustments.

I second the above method.

 

[Dan-Ark]

Great info guys, thanks too all! I don't think I have foam generators? just 2 (for brush) lines that connect together in brass fittings just before the boom. the tri foam seems to be just 4 lines going into brass manifold just before the hose to the gun

 

[2Biz]

I usually turn the air off and get the chemical flow I am looking for to the bays, then start to adjust the air to get the lather that I am looking for. Start with furthest bay from equip room then when finished that turn them all on and make any small adjustments.

Makes perfect sense unless you have flow-meters. With flow meters, get one bay set the way you want then set the flow the same to each bay. Length to the furthest bay is a non issue. Take my FB for example. The flow rate is 20 oz per minute to each bay which is set using needle valves on each solenoid. As long as you have the same flow to each bay, they all perform identically regardless of distance from the ER. No need to run back and forth to get all bays running similar or starting them all at the same time to make adjustments...

 

[cityview]

That shouldn't happen as long as you have a positive air flow through the regulator. If you have leaky solenoids, they should be replaced. If you are running flojets, you might want to put solenoids on the air supply to the flojets to eliminate issues with leaky or stuck open chemical solenoids. It seems this always happens when you are not there and you end up wasting a whole 5 gallons or more of chemical!! The air shutoff solenoids eliminate this and give you warning as to when something is wrong down-stream.

BTW, if you are running flojets, when you are there and no one is using the bays, do you hear the flojet/flojets cycle even though they are not in use? If they do, that's the indicator that you have chemical solenoid issues that need fixed. They should not leak by.

I go through 5 gallon buckets like its my job because solenoids stick or a line breaks. Its happened 3 times in the last 3 months!

You have me very intrigued by this idea of having an air shutoff solenoid. How do you have it set up?

What is "triggering" the solenoid to open or close? or do you have one that somehow does it automatically? And if so, what kind is it?