Posted by tarzan on December 14, 2001 at 04:36:16:
In Reply to: proper boiler venting posted by Jim Clark on December 08, 2001 at 07:07:35:
Yeah, I can give you a reason, but your boss sounds too stupid to understand....
We have recently discovered that water boils at 212 degrees at atmospheric pressure...'Venting' a boiler when the water in it is still above 212 degrees will allow the boiler water to continue to boil off and possibly lose water to an unsafe level exposing boiler tubes to excessive temps...let the boiler cool till the water is at 200 F...
It's guys like him who never take time to do things right, but have to make time to do it over.
: I have 2 Cleaver Brooks 800HP firetubes that put out about 28,000 lbs/hr at 150 lbs. Had one on manual low fire and one swinging with load. Total flow was 16,000lbs/hr when sight glass on one began leaking. Sight glass isolation valve leaks by slightly so plan was to bring boiler down and make necessary repairs. No emergency since load not expected to spike any higher than 21,000 lbs/hr for the next few days at least. Impatient boss wanted me to hurry cooldown by having me vent at 75 lbs. Knowing I would have to throttle vent valve to prevent water spew, I refused to vent primarily to prevent a cut valve. Plus I have never been a big fan of cooling down faster than normal recommended manufacturers guidelines unless an emergency required me to do so.
: Needless to say I got my butt chewed out. He went ahead and vented, resulting in a cut valve. He has now had a second valve installed on top of the cut one. One for throttling and the other for a stop.
: My question is, can anyone give me any more reasons than a cut valve as a reason not to continue this practice?