I was reading a 1970s dredging manual from the Army Corps and it said you can lose up to 40% of your pump efficiency just from a worn impeller. That's way more than I thought.

3 comments

3 Comments

That's a crazy number. Always figured wear was a slow drain, maybe 10-15 percent. Seeing 40% in an old manual hits different, they weren't messing around. Makes you rethink skipping that inspection. Changes how you look at the whole system's performance.

terryr463mo ago

You're right @abbyr96, I've seen pumps lose half their flow from a bad impeller.

henderson.kim1mo ago

Man that 40% number really sticks with you once you see it in person. Had a buddy with a chiller plant where the pump sounded fine but flow was way down. They pulled the impeller and it looked like someone took a cheese grater to the vanes. Just rough edges and pits everywhere. That kind of damage builds up slow so you don't notice until something else fails. By then you're already losing efficiency and wasting power for months. It's wild how much you can lose without hearing anything different.