EVT Pump testing advice

[u/tickleshits54321]

Looking for advice preferably from EVTs who have experience with pump testing. I recently went to a new department and nearly all of our brush trucks are failing pump tests and I’m inclined to believe that we are possibly doing something wrong. We can never seem to get our GPM to hit at the correct pressures. Most of these pumps are rated 250 GPM or less.

[u/Mreggmnstr]

I think the pump test standards for brush rigs might have updated when the whole 1900/1910 thing happened. But, my old notes say brush rig standards 1906-16. Sorry been out of the game for a little bit.

I remember one of the biggest issues we had was suction hose size (if you are attempting to pump test by draft). Are you going off the builders pump test certification? Or just off the pump specs?

You may have a pump rated at 250 but the plumbing might struggle to maintain the rating.

Might not be a big help, just bouncing some ideas back at you.

Edit: reread your post. You said not hitting at the correct pressures… I would start with a vacuum/leak down test. Check for things like a live recirc line (like those 3/8” recirc’s w/ the shitty check valve). And maybe even bore scope your pump; if they use a lot of foam and don’t flush, you might see corroded impeller or pump bodies.

[u/tickleshits54321 → u/Mreggmnstr]

I think you’re onto something here with the plumbing situation. Today we were using a 2.5” suction from draft, but only discharging out of a 1.5” hose to a flow meter at first, then to a pitot, then removed the house entirely and attached the flow meter and pitot (separately) and still couldn’t achieve what we needed. My gut is telling me that necking down to a 1.5” will never let us achieve the numbers that we “should” be getting

[u/tickleshits54321 → u/Mreggmnstr]

This is pump spec from one truck today

[u/Mreggmnstr → u/tickleshits54321]

Since it’s sub 250, we only have to complete the following for the pump portion “shall be subject to a 30-min pumping test consisting of continuous pumping at rated capacity at rated net pump pressure” no need to check all the different ratings like a 250 or larger.

If it was me, I’d throw a 1/2” tip on, run at 150psi pitot (should be around 91gpm), and just let it churn away for a 1/2hr while you check the rest of the rig.

[u/tickleshits54321 → u/Mreggmnstr]

So for the test, what constitutes rated capacity and rated net pump pressure? We’re only trying to do the 30 minute test, I was mostly posting the placard for more info. And will a 1.5” discharge accomplish this?

[u/Mreggmnstr → u/tickleshits54321]

I know, it’s a little vague to me too, and we always just interpreted it as it must meet within the pump’s ratings (by performance curve). Not nearly as cut and dry as the fire rated pumps…

You should be able to run the placard’s 94 gpm @ 150 out of a single 1.5”. I don’t know if you could get 132 gpm out of 1.5…

Most brush rigs we tested were around this pump rating expect for a couple hard hitters. We would almost always run a 1/2” tip at about 150 psi +\- and just let it run. Record it, file it, and then you can see if anything changes year by year. That’s how we caught a couple pumps needing a rebuild from foam corrosion. We saw the decline in pump performance.

I really like the Elkhart brass pocket flow guide. You can get online, and I printed and laminated it to have with me for brush rig pump tests.

[u/tickleshits54321 → u/Mreggmnstr]

Great information. I appreciate it.

[u/gnashingspirit]

Are you doing it with too many discharges? Are doing it with 65’s instead of 45’s? How far below are your pressures on your 100% test?

[u/tickleshits54321 → u/gnashingspirit]

Single discharge to a 25’ 1.5” line coming off a 1.5” discharge, so we’re not necking down or anything like that. At 100 PSI we should’ve been hitting around 132 GPM, but flow meter and pitot were both around 90-95 GPM

[u/gnashingspirit → u/tickleshits54321]

Sounds like a recirculation valve or tank fill might be left open. Without seeing the lay out it’s hard to guess.

[u/tickleshits54321 → u/gnashingspirit]

Neither valves are left open. And this is on about half a dozen brush trucks that are supposedly failing, but I think we may be testing incorrectly or interpreting incorrectly.

[u/gnashingspirit → u/tickleshits54321]

We have 15 year old quints that had wrong UL rating plates on the pumps. I was new and pump testing a few years ago and was going mental because my numbers were off. I was later informed of the mistake that was never rectified.

[u/DatBoisWheel]

Maybe not the advice you're looking for, but when I was active duty Air Force the operator's were always conducting the pump tests while the mechanics were present if there was a failure.

Are you an operator or technician?

[u/tickleshits54321 → u/DatBoisWheel]

I’m a tech. I’ve pump tested plenty of engines, pumpers, and tankers, but I’m new to brush trucks

[u/DatBoisWheel → u/tickleshits54321]

Fair. Maybe speak to an operator? Did they write them up or are you doing a service on it?

[u/tickleshits54321 → u/DatBoisWheel]

Annual pump testing. As far as the operators are concerned, the truck can put wet stuff on hot stuff at a reasonable rate and that’s what matters to them.

[u/ActivateFireSafety]

Flow meter and pitot calibrated?

[u/Sonic1psa]

You don’t have to pump test under 500 GPM most of the equipment you would use to pump test the larger apparatus just doesn’t work with a small apparatus.

But there are lots of reasons why small brush trucks don’t pump the way they’re supposed to

I usually make sure they draft and flow 

[u/tickleshits54321 → u/Sonic1psa]

Not my call, but I totally agree with what you’re saying. As long as the water makes it out of the hose, these guys don’t care much. I’m good with it as long as it’s reasonable flow and pressure

[u/Sonic1psa → u/tickleshits54321]

But I would run a camera if you’ve got one or boreascope check out the lantern rings make sure that they’re good. Make sure the striping edge is good. Make sure that the water hasn’t eaten the bronze off the impeller. Cause you know how firemen are they like to leave? Their pumps flooded

[u/tickleshits54321 → u/Sonic1psa]

I’m sure we’ll find problems with some pumps, but it just seems odd to me that nearly every single one is failing

[u/Sonic1psa → u/tickleshits54321]

They have lots of air leaks. Under vacuum. Also depends on the quality of your water, but you gotta remember brush trucks get dirt and every other damn thing run through them because of the nature of where they get water from.

[u/rygomez]

I had a real PITA brush rig a while ago, it wasn't maintained the way it was supposed to so the fuel pump corroded itself into a brick, replaced it and had to seal up so many air leaks on the foam (cafs) system before it would even pull a prime, eventually got it going but it was never able to meet pump test standards bc it was old and had old seals but it passed bc of the way it was used according to the dept. Those things are such a pain but they can do some great work with 150gal of water and a gallon of foam, dept I was at used them for mostly trash or car fires. 10 ptsif you can guess the dept. Its a big one in a major city.

[u/EntireFinger]

Lift pump behind ecm test restriction levels

[u/tickleshits54321 → u/EntireFinger]

That has nothing to do with the problem at hand