Bays cavitating only when all bays are full?????

[csmith]

I've got a 5 bay wash, when all 5 bays are full and running 3 of my 310 pumps closest to the water bin start cavitating bad, sounds like pumps are running out of water but I look in the water bin and there is plenty of water, when it's just one of two bays running everything runs like it's suppose to..... any suggestion or advice???

 

[DakotaHoskins]

We started using all hot water not just for rinse. So we had to drill another hole out in hot water tank to use for one of our bays because they were competing for water. We have a 4 bay. Not sure if this is what your problem could be.

 

[Randy]

Cavitating pumps not good for the pumps, I’d be getting that problem corrected ASAP. You could have an obstruction in the feed line from the water tank or an under size water line feeding to pumps. It could also be that when the tank refills you’re getting turbulence in the tank that is causing air bubbles and the pumps are drawing in these air bubbles. I hate gravity fed pumps, they seem to have more problems with head washout etc.

 

[MEP001]

I've got a 5 bay wash, when all 5 bays are full and running 3 of my 310 pumps closest to the water bin start cavitating bad, sounds like pumps are running out of water but I look in the water bin and there is plenty of water, when it's just one of two bays running everything runs like it's suppose to..... any suggestion or advice???

I have seen this before a number of times. Since it's the pumps closest to the tank that start cavitating, I would assume there are two lines with one running three bays and one running two bays with the line to three bays being too small.

 

[mac]

Have seen this before and it can be annoying. What I found that causes this is a bad check valve on the inlet side of a pump. A lot of systems have a dual water feed. That means the pump can get water from the holding tank, or from a pressurized source. If that is your case you have a check valve on the gravity feed side of the pump to keep the pressurized water from filling up the holding tank. If that check valve goes bad, then when a low pressure function is selected, that water with air in it goes back through the high pressure line, then back through the pump and check valve, and into the holding tank. Then when another bay is running high pressure, it sucks in the water with the air bubbles in it, and voila, you get cavitation. An easy way to check this is to turn on one bay at a time on tire or presoak, let it run for a minute or so, and watch the holding tank. When you see air bubbles coming in from the bottom of the tank, you found the bay with the bad check valve.

 

[lilb93]

I had almost the exact same thing, only when really busy and all pumps were running at the same time. It was never out of water to the pumps at all it drove me crazy. The soap feed and wax feed 1/4" plastic hosed going to the pumps were the problem. when all pumps were running it would create a vacuum asking for water and there was enough water. where the plastic lines plugged in to water line going to the pump they were sucking air...
Took each one off and cut off about 1/2" and plugged them back in. That cured it, when you look at the hose before i cut it you could see the ring around the plastic from the o-ring in the fitting.

 

[2Biz]

Another issue I see with sharing the same water supply lines would be varying soap and wax feeds based on pump suction vacuum. (Depending on how many pumps are running at a given time)...That would drive me and customers nuts!

You might consider running individual 1/2" Poly Braid back to the tanks for each pump like pictured...This way the suction/vacuum to each pump is always the same. I never have any issues with varying soap/wax feeds or pump issues...I've never had to re-adjust any of the soap/wax needle valves since I installed the new tanks...About 3 years ago...