condensation in firetube boilers

Anna Conda

Its not quite clear from your post... Are these steam boilers or hot water boilers? The pressures suggest steam, but the mention of expansion tank suggests hot water. What is the MAWP of the boilers? What is their normal operating pressure?

jrh

i recently got a no heat call from a school with two double pass firetube boilers. upon arrival the boilers were at 30 psi due to a maintenance man opening a bypass on the water feeder. all controls were weeping at the gaskets and the relief was doing its job maintaining 30 psi. after adjusting pressure and bleeding the expansion tank i fired the boilers up. i immediately got water leaking out of the fire door and rear flue collector. upon inspection it appeared that all of the tubes were weeping around the roll press. at first i thought it was condensation but wasnt sure. i dropped boiler pressure further to 8 psi sacrificing the 2nd. floor just trying to get heat on. it appears that the water stopped. and has been running now for a week with no water. also the temp upon cold startup was still 80 degrees. any input would be appreciated.

EBEBRATT-Ed

As you mentioned at start-up the boiler temp was 80 deg. Your sure to get condensation until it heats up.

If you shut the heat off and the tubes start leaking--then you probably need to retube or re-roll. Sometimes the tubes are borderline leakers and when the boiler heats up and expands it stops leaking.

ED

oil-2-4-6-gas

the pressure --suggests Hot Water system , yes you will get condensation --especially with gas --2 things i would do #1 run it to 160* open fireside and check for leaks #2 would be leave it off for a day open -check for leaks -- what brand boiler is it ?? 2 pass suggests a pin style --3 pass would be a Federal brickset(old) a host of many other --bricksets/--scotch marines Eastmond Federal(new)and also a host of others -

jhansen

im sorry mentioning expansion tanks and 30 psi reliefs i guess i assumed you would know i meant hot water. sorry.

jhansen

mawp is 30 psi

Anna Conda

Not a problem. Where I'm from, I've always heard hot water systems described by temperature, not pressure. In fact, most of the water systems I've worked on don't even have a pressure scale on the gauges, just temperature. Other regions may be (and evidently are) different. That's why I asked.