Soap Feed Issue

[2Biz]

Soap to each pump is gravity/vacuum fed through 1/8" poly lines connected to a 1/2" PVC pipe back to the mixing tank. Sometimes it takes about a minute for soap to get to the bay even though I'm getting flow (14-16oz a minute through the Dwyer flow meter) indicating the mixture is diluted in the 1/2" pvc pipe/manifold back to the tank. Once soap gets to the bay, show is normal. I can then go to any other bay and get soap to the bay in about 10 seconds which is normal. It seems this issue happens only when the wash has had no activity in awhile, all bays dry. Maybe when soap isn't selected in awhile? I have no way of knowing that. No matter which bay I try first (After all bays sit awhile) I get the same results.

When switching each bay to rinse, I see no soap in the rinse water indicating all the soap solenoids are seating. My soap tank doesn't seem to be diluting either...It never runs over and the show in each bay is always the same once soap reaches the bay.

Any Ideas as to what could be causing this? I just noticed this happening and don 't know what could be causing it. I don't have check valves on any of the 1/8" poly lines. BTW, I have weep guns so when the system goes into bypass when the trigger gun is released, there shouldn't be any positive pressure on the soap lines, so I'm stumped.

 

[boywonder]

1/8" hoses are awfully small. I plumb from the tank 3/8" and bring it down to 1/4". You might have a soap solenoid plugged up.

 

[2Biz]

You are correct. I have 1/4" OD poly lines. I had I.D. in my mind for some reason... If one of the solenoids is sticking or plugged, I'd either get no soap in that bay or soap in my HP rinse. Neither is happening?

I considered running individual 3/8" poly lines back to the tank, (make a Short manifold) but this wouldn't solve my problem completely, only make less volume in the supply lines if I was getting some sort of back-feed of HP rinse. My Wax works like it should 100% of the time. Its plumbed Identically the same as the soap.

 

[MEP001]

You might have a soap solenoid not seating completely, and after things have been sitting for a while the water in the gravity-feed tank is flowing back through one of the soap lines and into the soap tank.

 

[JIMT]

2Biz,
Is your soap tank at a lower level than the rinse tank and the pumps? If they are, when you turn to soap the rinse water at the pump is trying to push the soap back to the soap tank. When nothing is running then the soap in the lines is trying to run down into the soap tank then it would take a while to suck the soap up to the pump. That is all that i can think of. 60 seconds is a long time for this to happen.
JIMT

 

[2Biz]

It has to be one of the solenoids, but which one? The 1/2" PVC manifold is about 8-10 feet long and can have a bit of volume in it if its filling with water. If I change out all the solenoids, I think I'll re-plumb and take separate 3/8" poly back to the tank for each pump. If this happens again, it will be much easier to determine which solenoid could be failing.

Thanks for the replies!

 

[2Biz]

Is anybody using the KIP Manifolds like this for Gravity Feed Soap and Wax?
https://www.kleen-ritecorp.com/p-1973-kip-manifold-blocks-metering-screw-4-outlets.aspx

They have (2) 1/4" NPT inlet ports, one on each end. I'm going to go with poly tubing and SMC push to connect fittings but am wondering what size supply tubing (from the mix tanks) to use and if I need to use both ends of the manifold. Since its going to be vaccum fed, I would think you'd need the most volume you can get.

I'm wanting to get away from my current setup (you can see why in the photos below) and make it as simple as possible to work on. I'm thinking the Kip Manifold would be the best way to go and I can put them out in the open and get away from the current solenoids being so hard to change out.

<br>

 

[MEP001]

I have replumbed pump stands and used the Kip manifolds at the customer's request. It worked just as well as with individual solenoids. I supplied them with 1/2" ID polybraid hose and plugged the other port, which is there either to couple multiple manifolds together or to mount a gauge. Since the manifolds ended up on one end of a long pump bench, I used 3/8" OD tubing for the runs to the pumps so line loss at the farthest ones wouldn't be an issue. I used the John Guest swivel tubing fittings since the ports are so close together.

I generally prefer individual Kip solenoids mounted on the underside of the electrical box with the coil inside. The cost is about the same vs. the manifolds. The main reason I prefer this is because I can service one bay without shutting the whole wash down.

 

[Jeff_L]

There are pros and cons to doing it either way. I use a kip manifold to one location and individual solenoid s at another. I do prefer the individual solenoid s for the same reason MEP does, easier to work on. When using a manifold you have to shut everything down that's on that manifold to work on it. Thus, it gets tough to repair during a busy time.

If you haven't done it already, I would check each solenoid between your soap and the pump. If you don't notice the level going up, it may be a very small leak in the solenoid. Just enough to dilute, but not enough to notice. If you have a shut off valve between your manifold and solenoid, you could shut off the soap, and disconnect the input line and then run the rinse function for that bay. Look for water coming back through the solenoid.

 

[2Biz]

I have enough room between the (2) stands to mount the Kip Manifolds so the lines out to the pump will be minimal length and the same on both sides, maybe 4 feet at the longest. The tubing length back to the tank is 6 feet. If I use the John Guest or SMC fittings and I have a problem with a bay, I can change out the whole manifold in a matter of minutes and bench test the problem child off the stand. I'll have to keep a spare to do this, but I am looking for time savings and ease of making the repair. Quite frankly the old Mark VII is very hard to work on and you can see why from the pictures. Engineers have came a long way since then.

Mep, If you use 1/2" ID Braided Hose to one end, do you think 1/2" OD poly hose will work? It has a 3/8" ID and would be the same as using 1/2" Braided with a barb fitting. The 1/2" Barb fitting has a 3/8" ID. Same restriction. I have 1/2" Poly hose and 1/4"npt x 1/2" fittings. The through hole on the SMC fittings is 3/8" same as using a barb fitting.

 

[2Biz]

BTW Jeff_L Thanks for the suggestion, but as you can see from the pics, the solenoids are tucked in behind the flow meters and are very difficult to remove. The is no room to screw the solenoid out of the PVC tubing. So you have to take the whole PVC manifold out which would be a pain. Would be lots easier to redesign using the Kip Manifold with push locks. I plan on redesigning the whole stand using the Kip Manifolds. Keeping it simple and minimizing spare parts is what I'm looking for.

 

[MEP001]

For just four bays and if the run from the soap tank to the manifold is short, 1/2" OD tubing should be enough. I just prefer overkill to plumbing like that so there's no variation in the soap if all the bays happen to be drawing from it at once.

You wouldn't need a spare manifold to swap out for service because the Kip has individual cartridges that are quick and easy to swap, but you'd still have to shut the bays down to do it.

 

[2Biz]

I found some great info on flow rates that includes smaller I.D tubing that we use. The difference between 1/8" and 3/8" tubing is about 9 times greater flow at the same PSI. So the 3/8 I.D. poly tubing should be twice the capacity I need to supply a 4 bay manifold.

List of calculators and tables:
http://www.pneuaire.com/cochandta.html

Pressure Flow Table:
http://www.pneuaire.com/prflta.html

Vacuum Table:
http://www.pneuaire.com/vaflta.html

 

[2Biz]

Not to bore any of you, but thought I would post updated pics (Before and after) of the Soap and Wax plumbing upgrade. The forum is a great reference tool for me. And sometimes I go back and review what I've done in the past to see why and what the hell I was thinking!

I decided it made much more sense to change out the old PVC manifolds for new and just reposition the solenoids to make it easier to work on instead of using the Kip Manifolds. I ended up using Kip Metering Solenoids which I don't necessarily like. Their not easy to adjust with the pump running. I wished I would have used standard solenoids with screw in metering valves. It would have made adjusting a lot easier. With the new position of all the solenoids I should be able to change one out in 5 minutes or less. I'm using the SMC push to connect fittings which helps with change out. I have ones coming for the Dwyer meters and will install them when they come in.

Now I get soap and wax in my furthest bay (3 bays away) in about 10 seconds. 6 seconds in the bays next to the ER. Problem solved.....

 

[Randy]

Looks good. I use the same valves on my High Pressure soap and Wax. In the 15 years they've been installed I've never had a problem with them.

 

[MEP001]

That looks a lot better. I've done basically the same thing before, except I used copper instead of PVC (I just like the rigidity).

You couldn't bring yourself to eliminate the flow meters and needle valves, eh? Maybe you could test how it would work by opening all the adjustments fully and controlling the strength of the soap and wax in the tank.

 

[I.B. Washincars]

Just to one-up you guys, I just replaced mine with stainless steel. I don't like that you don't have a hose where you jump from one pump stand to the other. I would be concerned that it may break since the stands can move independently of one another. I know from experience that the legs on that set-up can rust completely off and the stands will start leaning. When I finally scrapped mine last year, one side had collapsed and was leaning back about 3".

BTW, yours is older than mine that caved in.

 

[2Biz]

You couldn't bring yourself to eliminate the flow meters and needle valves, eh?

Your right! Just couldn't! But for a good reason...I think. Because I still have the hot and cold supply (Basically both cold), creating the same vacuum through the plumbing to each pump would be rather hard to do. BAsically each needle valve is adjusted differently to get the same flow, say 10 oz. per minute because of the different vacuum each set of plumbing creates. Largely because of how the water supply gate valves are adjusted. It would be very difficult to get them all the same. So that is the reason I kept the needle valves and Dwyers. I'd have to get rid of all the water supply tubing and supply each pump with 1/2" hose from the tank to be able to get rid of the Flow Meters/Needle valves.

I don't like that you don't have a hose where you jump from one pump stand to the other. I would be concerned that it may break since the stands can move independently of one another. I know from experience that the legs on that set-up can rust completely off and the stands will start leaning. When I finally scrapped mine last year, one side had collapsed and was leaning back about 3".

BTW, yours is older than mine that caved in.

Good catch! I left the metal loops "Loose" that hold the PVC to the frame. The pvc can slide back and forth easily. My pump stand frame is still in pretty good shape. Really not much rust. Although its pretty thin. My mix tank is another story. The cross braces are gone. I had to build an ajustable frame and put under it to help support it. I think I can get another 10 years out of it!