Economizer on water tube boiler life span

20ozjolt

I'm seeking information on what the projected effective life span should be on a feed water economizer on a 850HP watertube boiler before it develops leaks. 

Currently attempting to chase down a down time humidity issue in a 1968 water tube without spending the 30K for a contractor to do a pressure leak test. 

retiredguy

There is no way to accurately predict the effective lifespan of an economizer in a high pressure steam boiler. A good certified boiler inspector can give you the supposed condition of the tubes in the economizer but a complete hydro test is the best test of it's integrity. How long will a certain economizer last is dependent on a lot of factors such as the quality of the feed water, and the type of fuel burner + the cleanliness of the exhaust gasses. You can kill a water tube boiler in a couple years or have them last 50 + years depending on how it is run and maintained. On a boiler of that size, the $30,000 for a pressure test (full pressure hydro test) is "chump change". Do the test. You are not going to save the customer any money by just guessing.

EBEBRATT-Ed

There is also a test for checking tube thickness it is most often used with chillers but I think it can be used on anything with tubes.

Eddy current testing

20ozjolt

Didn't think about an eddycurrent test on part of a boiler. Interesting thought.

We do that on our chillers every few years....

Ya 30k is not a lot normally but I think I've spent about 500k in the last few months fixing stuff in our plant sence I was stuck down there I just keep finding issues where the previous solution seemed to be ignoring it until it was worse... now every time I submit a PO my boss says I'm going to get him fired if he keeps approving them. Lol

Sadly he is also new to his position.

Gsmith

Ah, 1968 boiler. 2023-1968=55 years old. Has the economizer been replaced or is it original? If original, maybe time to start planning on a replacement. Mechanical things, no matter how good and how well maintained don't last forever.

retiredguy

Boiler shut down time, if it shuts down the whole plant or restricts the plants manufacturing capacity, would be much more expensive that keeping the steam plant operating efficiently. That 850 HP water tube boiler is a fairly large size boiler and requires a lot of TLC and maintenance.