TIL you can burn out a dredge pump running it dry for too long

I was down at the Green River site last Thursday and noticed a guy letting his pump run with no intake for maybe 10 minutes while he was messing with the hose. That thing seized up before lunch and cost us half a shift to swap it out. Has anyone else had close calls with cavitation or dry running on a similar setup?

3 comments

3 Comments

mark_green5d ago

My old 4-inch pump seized up on me last year down on the Willamette. I was trying to clear a jam in the intake hose and left it running dry for maybe fifteen minutes while I poked around. The funny part is I thought I was being careful by keeping the throttle low, but that didn't matter at all. When I finally hooked the hose back up and hit the full throttle, the thing just made this awful grinding noise and quit. Cost me four hundred bucks for a rebuild kit and a whole Saturday to fix it myself. I figure I've paid for that mistake twice now in parts and lost time.

josephbailey5d ago

Learned that lesson myself a few years back with an old MP pump on a gravel pit job. Kept a 3-inch submersible running dry for maybe twenty minutes while I dug out a clogged screen. Thought the low idle would save it because the water was just barely trickling out. Nope. Seals were toast and the impeller had welded itself to the housing by the time I got back to it. Now I just shut the whole thing down anytime I need to mess with the intake. Had to replace the pump entirely because the heat warped the housing so bad nothing lined up right. Costs less to waste five minutes shutting it off proper than to explain to the shop why you need a whole new pump.

gracethomas5d ago

Pulled that same stunt myself with an irrigation pump and ended up with a melted impeller and a six hundred dollar lesson.