Soap Back Flowing Into Rinse Tank Laserwash 4000

[loewem]

Having a problem with pre-soak back flowing into the rinse tank. I starts at the end of the 1st pre-soak pass. Soap is back flowing steadily from the smaller pick up up tube in the rinse tank. This continues through the end of the second pre-soak pass. When the high pressure rinse kicks on it takes about 8 to 10 seconds before high pressure begins and it is only producing at about 750 PSI.

What has been done so far:

- replaced check valve prior to where low pressure T's into the high pressure rinse hose.
- checked all danfoss valves at injectors.
- removed the hoses from the high pressure chemical injectors, plugged the hoses and ran pre-soaks manually.
- rebuilt the lexair valve for the high pressure rinse.

PDQ suggested removing the overhead low pressure lines to see if chemical back flows from any one line. I don't see how it can be on the low pressure side.

Thanks in advance for any help.

View attachment 1018
https://youtu.be/peB3Yrgy-20

 

[pgrzes]

Had problem on my High Velocity. We had just installed new unloaders. 1 of them was sticking.

 

[tdlconceptsllc]

The low pressure check valves on the wall above your pump stand that T into the big stainless manifold before it goes into your foaming/scrubby pad one of those 1/2 or 3/4 check valves may be may be bad. PDQ is saying take each hose coming off the danfoss hose at the tree/overhead manifold and leave one attached like soap 1 and press 100 enter 10 enter and see if soap is coming through the other valves then you know you have a bad Danfoss or check valve. (I always test danfosses and take them completely off the injector to get a sure test also.) good luck

 

[loewem]

Thanks for the help. Rebuilding the hp unloader fixed the soap on the rinse tank problem. I had a problem with a pop off valve releasing diring the hp cycle. Traced it back to my clear coat danfoss valve. It is happening again and thinking it might not be a danfoss valve. Could it be one of the check valves?

 

[bryan church]

You have a cracked PVC fitting inside your HP rinse tank. Or the 1 1/2 PVC check valve inside the HP rinse tank is bad, or the union is loose.