condensate pump rebuild

Ken_40

John_102

condensate pump rebuild

I've got a 50-year-old Roth pump that has given up the ghost. Motor is fine, housing looks good. Roth will supply the impeller, bushings, seals etc. I'm betting the circular mesh screen surrounding the intake won't be included. It looks like bronze window screening.

Question: Will standard bronze window screening work? I'm assuming galvanized, aluminum, or fiberglass screen won't work (or at least not for very long).

Ken_40

My experience has been...

bad with these sorts of rebuilds.

Corosion in the seal bosses, unseen until completely torn down, pitting, incorrect parts (updates lost to antiquity), labor to rebuild (and iffy results) when new ITT simplex at 15 gallons are under $500...

But yes. A bronze mesh screen is what's needed. Most industrial hardware places, maybe even Grainger may have "stock." If not, uou could always cannibalize an old (or new)bronze screen oil-filter basket? Cut the shape you need, the stuff's like 10 gage!

But, if they have the rebuild/re-seal kit, they should also have a screen filter too, n'cest pa?

John_102

Thanks...

for your advice & your warning. I'm certain what you say is dead on. However, I hope to replace the boiler, the zone valves & the condensate return soon - perhaps in the spring.

My plan is to do away with all the complications & head back to gravity. Therefore, I hope to get another season (or two at most) out of my rig. My timeline is hazy because it's hard to find knowledgeable steam pros down in the sunny South. (Think, however, of the opportunities one of you guys could have - a paying job down here when your mates are still scraping snow off the windshield and then some fishing or golf before strapping back on your mukluks!)

Ken_40

****,

Jeff Lawrence is in Georgia, and about good as you'll find north, or south of the Mason Dixon wit regard to steam or hot water.

One of the best amongst "bests."

Christian Egli_2

Screening out the zinc

Repair or replace

When talking about an inside job, I always prefer trying a repair - no matter what we're talking about. It's a gamble, you put in your labor, and if it all works out it's like you hit the jackpot. If you break everything, well, then at least, you have a conclusive recommendation to buy something new. Lost time and labor, yes, but big learning opportunity.

And in both cases, you get away with learning some new tricks. Valuable in my book. What's more, during the investigative repair you might get to understand why the item failed in the first place and you might think of something better to do than just a plain replacement. Geniuses do that all the time.

If it is a billable job for a paying customer, then it's altogether different. Here having fun and learning takes second place to deliverability and reliability. Unless the owner demands and understands that the repair costs may be all wasted before a replacement purchase, then I wouldn't propose the fix-me-up option. And your pump is 50 years old...

There, a heck of a long blurb that doesn't answer anything.

The intake screen -- I'm not a fan at all:

Filters screen out some dirt until they become clogged (they often get clogged through their own corrosion). Once clogged, they are plugged and no longer let enough water through. Danger theatre. With a filter on the intake hole of the hot condensate pump, there is a risk of cavitation (just like with an unthrottled set up). This is a bad risk to take on casually. If the pump housing even goes dry, then it is no surprise for the seals to give up.

Furthermore, when the screen mesh falls apart, it will lodge itself in the impeller. That too is annoying, it destroys performance.

What's the risk with no intake screen? you'll suck up potentially large debris, just like you'll potentially suck up a chunk of the failing screen...

Dirt floats around in steam returns, that's not unheard of. It usually is dirt that settles nicely at the bottom of condensate tanks like sand in a pool; if your pump is not sucking directly from the bottom or if it is shielded by a little baffle to dam the dirt then there is not much risk of sucking up a large flake of rust. Floating tree trunks don't often come down the return lines either.

Condensate tanks need and should be cleaned out regularly. It annoys me that they aren't fitted with hand holes from the factory. And I would install a large strainer (that everyone can forget to clean) at the inlet to the condensate tank. Now your pump is happy.

What's the best metal to make the screen out of? I'd say stainless steel. I suspect bronze sheet metal screens are more often a variety of brass, which has no life expectancy in corrosive condensate. The type of steel or aluminum that makes screens has no chance either and zinc and zinc coatings wash away like mud - white mud. Brass is nothing but a copper and zinc cocktail and galvanization means slapping on a coat of zinc. I have enough Hoffman screens that are eaten away exactly at the water line to be suspicious of them.

Z is for zinc.

John_102

Thanks again, Ken & Christian

Ken, thanks for the lead on Jeff Lawrence. I'll do a bit more measuring & cogitating and then try to contact him.

Christian, thanks for your thoughts about the screen. You've given me a few ideas to consider. Yes, this is an inside job & I enjoy the learning process. (Understand that I draw the line at ignorantly messing with gas or foolishly imagining I can install a boiler - rebuilding a pump is about my speed.)

The old screen was fairly clogged. No strainer upstream. One of my intentions with the new boiler-to-be is to have strainers & dirt pockets where they ought to be. I've never understood shortcuts leaving such features out. The cheap man pays twice!

As to why I don't just order the thing from Roth, the answer is simple - I already ordered the other parts & thought I could find a solution locally rather than wait.

Again, thanks. You guys are a great resource & amazingly generous with your knowledge, patience & time.

Peace.

Ken_40

Class Act!

Anytime.

Anytime.