Presoak Adjustment

[caliwashes]

Hi all,

I’m running a Coleman Hanna setup at my self serve. Our pre soak is high pressure and gets pushed out by a CAT310 pump (same pressure as other high pressure functions). Yesterday when selecting the presoak function there was barely any pressure for bay 3. I completely unscrewed the adjustment valve and cleaned it of any debris and put it back and it worked for a few hours. We are running into the same issue again. The pump engages when the rotary switch is turned so I know it’s not a rotary switch issue or an electrical issue. Please let me know your thoughts. Please see picture attached. Thank you

 

[Greg Pack]

What you are working on only controls the soap concentration, not the output pressure. That's a medium pressure presoak system. On the discharge side of the pump is a solenoid and a brass regulator behind it. When someone selects presoak in the bay it open the solenoid and allows the pressure to drop to whatever the regulator is adjusted to, usually 400 psi. Your problem with low pressure lies there. With presoak tuned on it the bay screw the brass regulator down clockwise and you should see the pressure rise on the gauge, again 400 psi is the typical setting. Once it's turned to the other high pressure functions the pressure should rise to 1100 psi or more. If it doesn't that presoak solenoid in front of thew regulator may be stuck open.

 

[caliwashes]

Got it. Thanks makes sense. Will give it a shot and update!

 

[Greg_T]

Greg Pack has given a pretty neat explanation.

We previously had 400 PSI medium pressure pre-soak, but set up slightly differently to yours. It was an awful system that leaked all the time, as well as fluctuating in pressure and chemical concentration. We moved to a low pressure system by changing one of our hydrominder tanks from splatter wax to pre-soak. Splatter wax was rarely used, and low pressure pre-soak was a much better option.

Of all the changes we made at our wash, getting rid of medium pressure pre-soak was the best thing we have done.

Good luck getting things sorted out.

 

[caliwashes]

What you are working on only controls the soap concentration, not the output pressure. That's a medium pressure presoak system. On the discharge side of the pump is a solenoid and a brass regulator behind it. When someone selects presoak in the bay it open the solenoid and allows the pressure to drop to whatever the regulator is adjusted to, usually 400 psi. Your problem with low pressure lies there. With presoak tuned on it the bay screw the brass regulator down clockwise and you should see the pressure rise on the gauge, again 400 psi is the typical setting. Once it's turned to the other high pressure functions the pressure should rise to 1100 psi or more. If it doesn't that presoak solenoid in front of thew regulator may be stuck open.

Seems like our presoak solenoids on the pumps are not working and have been bypassed. That’s why our presoak has always been high pressure around 1100 PSI. So regardless of whether or not the solenoid is open it should at least have pressure. Thoughts?

 

[Greg Pack]

Seems like our presoak solenoids on the pumps are not working and have been bypassed. That’s why our presoak has always been high pressure around 1100 PSI. So regardless of whether or not the solenoid is open it should at least have pressure. Thoughts?

If high pressure wax and soap are still working fine I'd double check to make sure your presoak solenoid is indeed bypassed. Offhand I can't think of a way that the pressure would drop only on that function. This is assuming the presoak tank is not empty as the air coming in would cause an issue but the pump would cavitate badly and it would affect the other bays. Pictures of the setup and how they bypassed would be helpful.