Pressure throbbing

[James S]

I've got an alladdin 3500psi @5gpm hot water skid unit with a general pump. This past weekend, the pressure felt kind of weak and then it started throbbing or surging whatever you want to call it. It does it when I'm downstreaming or running high pressure. However, it does not do it when running upstream soap. It does have weak pressure from what it normally has when running soap, but it is not surging. I pulled all the check valves and found nothing wrong. I recently replaced the pressure switch for the burner and the unloader was replaced about 3 months ago. Has anyone had these type of problems?

 

[Larry L.]

(kind of weak and then it started throbbing or surging whatever you want to call it. It does it when I'm downstreaming or running high pressure.)

Sounds like a small air leak....



(However, it does not do it when running upstream soap.)

This sounds like a small air leak in your downstreamer line b/c it does not do it under high psi.

 

[James S]

It does do it under high pressure rinsing but not under high pressure soap....Would a bad thermal relief valve make it surge like this because it has been opening up a lot more often here lately.

 

[Scott Stone]

It still sounds like a small air leak. Probably somewhere around the fitting for the upstream soap injection. Another possibility is that the (Don't be embarassed if this is true) water filter is plugged, and the upstream soap is just enough to smooth out the surging.

Just a couple of quick off hand thoughts.

 

[James S]

I might try pulling the soap control valve off and putting new teflon on the fittings. I know it's not the water filter...that's always the first thing I check if I have a problem like that. Other thing is that thermal relief valve is leaking sometimes when I'm not even using hot water. I was using a turbo tip doing some oil-field work the other day and didn't have my burner kicked on yet and it was leaking.

 

[Larry L.]

thermal relief valve is leaking sometimes when I'm not even using hot water. \\\\\\\\\\\


Water pushes againest the valve,it does not suck to produce a air leak.


Change out your upstream soap line from pump to soap valve.,it still sounds like a small air leak,pin hole.

 

[James S]

That's what I thought as well about the trv. The soap line sounds like a very logical reason. I did check it over a few times and couldn't find a noticeable hole but I'll replace it tomorrow and see where I'm sitting at. Appreciate the help.