Irrigation pump

[ericm979]

My place in Oregon has a 15hp irrigation pump that pulls from the local irrigation system. I tried running it the other day when I was there and could not get it to prime. There's a priming pump on it. I closed the valve to the output pipe and opened the valve to the priming pump and pumped until I got tired, and never got any water out. Is there a technique to this? I tried running the irrigation pump a couple times in short bursts and it was clear that it was just moving air.

The source water level is few feet below the pump with a 5' long 4" suction hose with a heavy strainer on the end. I cleaned out the concrete box so there wouldn't be mud blocking the inlet strainer, and also tried it with the inlet propped up so it wasn't on the bottom. Nothing worked. I saw this system working when we were looking to buy the place, so I know it worked then. The sons of the owner told me that their dad had been priming it with buckets of water and they talked him into buying or rebuilding the priming pump.

The irrigation pump is a centrifugal Berkeley (nameplate in pics below).

 

[ponytug]

Does your intake strainer have a footer valve (check valve)? Those large bore pumps can be hard to prime if there is an air leak, either before the pump, or after it, and especially if the diaphragm in the hand pump or its check valve are cracked or have debris in them. I'd start with the upstream valve closed while priming, and then be ready to shut the prime valve and open the main valve.

All the best,

Peter

 

[ericm979]

Thanks! I hadn't thought about a footer valve but if there was it would help prime the system. I was hoping to avoid taking the suction strainer off the hose but I probably should. It was stored out of the water and covered but it could still be clogged or stuck.

It's possible that they put the prime pump on when the place sold and they stopped irrigating, and it never actually worked.

 

[ponytug]

Thanks! I hadn't thought about a footer valve but if there was it would help prime the system. I was hoping to avoid taking the suction strainer off the hose but I probably should. It was stored out of the water and covered but it could still be clogged or stuck.

It's possible that they put the prime pump on when the place sold and they stopped irrigating, and it never actually worked.

As this looks a bit too weathered for a recent installation, how about we bet on a reasonable seller, shall we?

You should feel the resistance of the water rising as you try to prime it. If you don't, either the priming pump is in need of service, or the pressure side valve is open, or the pipe to the irrigation ditch has a leak, allowing air in. This is a pretty simple set up as these things go.

The main pump is a very robust design for pumps, so if the motor is spinning, chances are the impeller is to and it should work. You might try a pint or so of water into the top of the manual pump to see a) if it stays, and b) if it improves the priming at all. Tuf-skins are very simple and robust, but need a new diaphragm, or perhaps its ball check valve is sticking open.

Is the primer pump side flapper present and not sticking?

All the best,

Peter

Berkeley pumps is now owned by Pentair;

https://www.absolutewaterpumps.com/media/blfa_files/B13323BK-P_Berkeley_Centrifugal_Pumps_Kits_Parts_and_Accessories_1-1-2025.pdf

 

[ericm979]

The flap is present and not sticking, though it seems like it doesn't seal until partway in the stroke. I tried helping it close with a finger but that didn't help.

The primer pump looks brand new, which is what made me think that it was added recently and maybe not tested.

 

[ponytug]

The flap is present and not sticking, though it seems like it doesn't seal until partway in the stroke. I tried helping it close with a finger but that didn't help.

The primer pump looks brand new, which is what made me think that it was added recently and maybe not tested.

Well, that's positive, but it should seal from the start, so a finger on it for the lift/upstroke/downward handle should help. If the priming pump is trying to move a fair amount of air, it may not feel like much initially, but the flap should definitely close.

Is the blue handle valve closed? Have you tried cycling it a few times?

Did you try adding some water to the top of the priming to check for leaks? You can remove the top to check the diaphragm and the check valve.

All the best,

Peter

 

[ericm979]

Yep I closed the blue valve and opened the red one. I poured some water into the top of the priming pump but I was thinking that it was a sliding piston not a diaphram and maybe needed some water to seal. A bunch of water came back out when I lifted the lever.

I think next time I work on it I'll check the inlet hose and disassemble the priming pump to check it for leaks.

 

[ponytug]

Yes, it's a diaphragm. I was thinking it might be a quick check on the integrity of the diaphragm, so if water sloshed out, it isn't totally shot. There must be a heck of an air leak somewhere else. Any chance of backfilling the blue valve water line, and then opening the blue valve, and starting the pump, to see if the pump will prime with that? Those centrifugal pumps are pretty good at pumping air to prime air if they have enough water to fill the pump somewhat. You just want sufficient water to keep the seals wet and lubricated.

All the best,

Peter