Speed up Foam Brush Soap Delivery Times? Check Valve?

[cityview]

My number 1 complaint is that the "Foam Brush" doesn't work on my 2 bays furthest from the pumps. People call and say they put the money in, but the foam brush doesn't work and they want a refund.

Every time I go test it, it works fine.

I noticed these calls are normally early in the day, so I decided to time how long it takes for the foam brushes to deliver soap for the first run of the day. It takes about 45 seconds on those two bays, but only about 15 seconds on the other two bays. The air lines deliver faster as well, which means you get some sputtering too.

This suggest to me that after about 15-20 seconds people think "it doesn't work", but the users later in the day get fast delivery and are satisfied.

So while everything is technically working, I want to improve the customer experience. Does anyone have advice on how to improve foam brush delivery time?

I thought maybe adding a check valve would help. There are no check valves on my foam brush lines, and never have been. I figured if I put a check valve on the top of the handle itself, that would be the FASTEST- but then I got a little nervous about freezing, so thought maybe I should put a check valve before the swivel.

Anyone have any advice on improving foam brush soap delivery time? Is a check valve the way to do it? (and if so, does anyone advise both which one to use and where to put it?)

Thanks a lot!

 

[I.B. Washincars]

It sounds like your foam generators are in the equipment room. For prompt delivery they should be as close to the boom as possible.

 

[OurTown]

How long of a run is it from the foam generator (or the tee for air injection/chemical) to the brush?

 

[Overachiever]

My foam brushes took about that much time when I bought my place, it ended up being because the weep was tee'd into the chemical line in the equipment room so it took that long for the weep water to get pushed out.

My chemical mixes on the roof with air right above the boom and I don't have any check valves.

Only other thing I can think of is maybe the air isn't high enough so the chemical is backing up into the air line and not going out to the brush.

 

[cityview]

It sounds like your foam generators are in the equipment room. For prompt delivery they should be as close to the boom as possible.

I have air/chemical Ts right above the boom. I get air right away, but it seems like it takes a while for chemical to get to the Brush too.

How long of a run is it from the foam generator (or the tee for air injection/chemical) to the brush?

Just about 15'

My foam brushes took about that much time when I bought my place, it ended up being because the weep was tee'd into the chemical line in the equipment room so it took that long for the weep water to get pushed out.

My chemical mixes on the roof with air right above the boom and I don't have any check valves.

Only other thing I can think of is maybe the air isn't high enough so the chemical is backing up into the air line and not going out to the brush.

I don't have a weep on the Foam Brush.

I'm at 40/30. I get air right away... its chemical I don't get.

I've got 3/8" lines for the chemical, and 1/4 poly for air.

I guess it could be too much air too... I'll mess with it a bit when I head out later tonight.

 

[MEP001]

It does sound like too much air, maybe mixed with a partially plugged generator.

What is the hose from the generator to the boom? I've seen many washes with a steel braided hose there which rusts inside and restricts flow. I try to use the biggest possible hose, preferably 1/2" and brass barbs.

 

[Randy]

What kind of pump are you using? How far is it from the pump to the foam brush? My foam generators are in the equipment room, the air is “T” into foam generator with a ¼” O.D poly tubing as is the foam brush soap and I have a ¼” hose going out to the bay. I’ve never had any complaints on how long it takes for foam to come out, but then I’ve never timed how long it takes. 45 seconds does seem like a long time.

 

[Earl Weiss]

My sugggestion is to put the Check valve at the end of the liquid line where it hits the T with the air line. This should keep the liquid line full of liquid. I could see the liquid draining out if not used for a long period and then the line has to fill with solution all the way to the T. I would also suggest removing any foam generators temporarily and see what happens. Agree with MEP try 20 PSI Air. Maybe even less.

 

[cityview]

It does sound like too much air, maybe mixed with a partially plugged generator.

What is the hose from the generator to the boom? I've seen many washes with a steel braided hose there which rusts inside and restricts flow. I try to use the biggest possible hose, preferably 1/2" and brass barbs.

Conveniently, I was going to replace all the manifolds in the ceiling because I have started cycling through check valve failures and pieces rusted together. Its probably a good time to replace those as well... however, they are standard 3/8" pre-built hoses screwed on to a T.

What kind of pump are you using? How far is it from the pump to the foam brush? My foam generators are in the equipment room, the air is “T” into foam generator with a ¼” O.D poly tubing as is the foam brush soap and I have a ¼” hose going out to the bay. I’ve never had any complaints on how long it takes for foam to come out, but then I’ve never timed how long it takes. 45 seconds does seem like a long time.

I actually just moved a few months ago to flojets from aro. That could have something to do with it...I know pressure is pressure, but priming can be different. The two in question are both 90-108' (5-6 18'ers) pump to brush. 1/4 is substantially less, which means the lines would fill much faster than 3/8. The Area of the 1/4 is .049", while the 3/8 is .11 That means 108' of line holds 142.5 ci of product for me, and 63.5 ci for you.... thats a whopping extra .34 gallons, or 43.8 ounces more product that has to be moved to get it to the brush. My Flojets in theory are rated for 5 GPM. So if it operates at rated throughput, it should take only 4 additional seconds to fill a 3/8 as opposed to a 1/4. In the scheme of things that is a lot, but when I'm looking at more than 45 seconds, that doesn't explain it.

What I don't know is how the 5 GPM is rated. Is that at peak PSI of 100? If so, is the throughput linear or exponential? If its linear, then at 40 PSI that would be 12 seconds, or 24 seconds over all. If its exponential, then that would be closer to 45 seconds... but then other people would be confirming they deal with the same things, so thats unlikely.

The resistance thing is interesting me though. I wonder if I'm having extra resistance at the Ts. I might just replace them and see what happens!

Much better at the math and computer sides of these things than the mechanical stuff, which is embarrassing as I'm an engineer.. haha.

My sugggestion is to put the Check valve at the end of the liquid line where it hits the T with the air line. This should keep the liquid line full of liquid. I could see the liquid draining out if not used for a long period and then the line has to fill with solution all the way to the T. I would also suggest removing any foam generators temporarily and see what happens. Agree with MEP try 20 PSI Air. Maybe even less.

I'll lower the 20 PSI and try that too. 30 PSI gives me a good foam... much lower and I can barely get winter foam brush to foam at all, but maybe the answer there is to add a real foam generator instead of just the T. I might go the check valve as well. It really can't hurt much.

Thanks for your thoughts.