Cat 310 Pump Pressure

[2Biz]

My wife and I should be closing this week on a 4 bay SS. This will be our first…The first thing I have to do is repair a Cat 310 pump (or motor) on the truck bay, which is down right now. The pump on the truck bay is set at 1500PSI. The other (3) bays are set at 1200 PSI which also use Cat 310’s. My question, how do you set/adjust pressure on these pumps? I’ve been to the Cat website and done numerous searches here and am coming up empty handed…Once I’m able to get in there and do some trouble-shooting, I can determine whether it’s the motor or pump. I want to be prepared if it’s the pump…..

 

[Tpoppa]

I bought my first wash (4 bay SS in Cleveland) a little over 2 years ago. There is definitely a lot to learn, but nothing too terribly complex. Good luck.

There are a few things to consider about pressure...
--The pulley sizes on the motor and pump determine the pump rpm and max pressure. You can swap pulley sizes pretty easily.
--The spray tips sizes also play a role.
--There should be either a pressure regulator or unloader on the output side of the pump. Assuming everything else is working properly, pressure can be adjusted up or down at the regulator/unloader.

If the pump is not making sufficient pressure, or pulsates, or is making noises...you likely have a pump that needs attention. This can be as simple as replacing pumps seals or the pump head could be damaged and need to be repaired or replaced.

 

[2Biz]

Thanks for wishing me "Good Luck" and the tips on the pump pressure.

I am getting anxious to get in there and get my hands dirty!

When we looked at the wash about 6 weeks ago, the owner showed me what the truck bay pump/motor was doing. It had kicked the 3 phase breaker and he just shut it down. It makes a very loud noise when the pump turns on. Still produces 1500 psi, so it might be the motor. Taking the belt off and starting the motor (checking load/amps) will tell the tale. Either way it should be an easy fix. I ordered the pump repair vid from Cat that is quite informative. Not intimidating at all after watching the vid. One thing it doesn't cover is the pressure regulator/unloader, so I'll see what I can dig up on it.

Thanks again for the help. I'll post once I find out what the culpret is....

 

[MEP001]

Just for clarity sake, an unloader should not be used in a self-serve car wash that has weep guns. An unloader relieves the pressure from the pump when the trigger is released so the pump runs with no pressure while there's no flow, and while it may work properly for the most part it can fail and cause serious problems. I've seen a Cat 530 blow a valve cap off and put a 1/2" deep dent in a wood ceiling 12 feet above the pump. A bypass regulator is cheaper, simpler and more accurate.

 

[Tpoppa]

MEP,

I have a Mark VII stand that uses these unloaders:

http://www.kleen-ritecorp.com/p-1961-giant-adjustable-unloader-1400-psi-13-gpm-yellow-springs.aspx

I use weep guns. It has been setup that way for years without issue.

 

[Randy]

I've used a Cat 7002 Regulator for the past 28 years with no problems

 

[2Biz]

I wish I had access right now. I'm curious as to how mine (Well almost mine) are set up. The suspense is killing me! I know there is a Weep Miser installed and working. So this will be something I need to sort out.....

 

[phred113]

Just for clarity sake, an unloader should not be used in a self-serve car wash that has weep guns. An unloader relieves the pressure from the pump when the trigger is released so the pump runs with no pressure while there's no flow, and while it may work properly for the most part it can fail and cause serious problems. I've seen a Cat 530 blow a valve cap off and put a 1/2" deep dent in a wood ceiling 12 feet above the pump. A bypass regulator is cheaper, simpler and more accurate.

You are correct. An unloader is not a good choice for systems with weep guns. Weep systems are different. Most all unloaders are trapped pressure types that require no water to escape inorder to keep the bypass open. If the trapped volume is lost, then the unloader will cycle, re-pressurize. This continuous cycling of the unloader is a tremendous shock to the pump and system.

Often unloader valves have their check valves removed and then they are just regulators, but look like unloaders. These will work with weep guns.

(more valuable information I learned from the folks at Arimitsu - that's why I like them. CAT wanted to charge me for their video, Arimitsu told me everything for free......To answer your question from a different thread)

 

[Greg]

Cat 310 pressure

When we looked at the wash about 6 weeks ago, the owner showed me what the truck bay pump/motor was doing. It had kicked the 3 phase breaker and he just shut it down. It makes a very loud noise when the pump turns on. Still produces 1500 psi, so it might be the motor. Taking the belt off and starting the motor (checking load/amps) will tell the tale. Either way it should be an easy fix.

2Biz,
You're on the right track and the forum here is helpful. Step by step diagnosis and patience will go a long way.

In addition to your motor test, this is a good time for a simple pump crankcase and bearing check; With the belt removed and a discharge port open, rotate pump pulley by hand for ease of rotation. Pump should rotate smoothly with minimal effort and no binding.

Some pump theory which may be helpful;
1) A pump produces flow, not pressure. With nothing connected to a pump discharge port there will be no pressure. Pressure is introduced to a discharge line based on the restriction of water flowing through a nozzle or multiple nozzles. Get your hands on a nozzle chart to view flows through various nozzle sizes at various pressures.......This is where the magic happens.
2) Triplex plunger and piston pumps are positive displacement. Pump gpm output will be based on pump rpm. Pressure in a discharge line is controlled by a pressure regulator or pressure unloader and protects pump from an overpressurizing condition. Water which is not needed to flow through a nozzle or series of nozzles to achieve pressure setting is automatically directed through the bypass port of the regulator or unloader. In a trigger gun application, the regulator or unloader reacts each time the trigger gun is actuated.

Good luck in your new venture!

Greg Thoennes
Sales & Tech. Support
Arimitsu Pumps