Posted by Vince B on February 01, 2000 at 19:46:28:
In Reply to: There are several possible consequences, all of 'em bad. posted by Mike Hinz on January 11, 2000 at 19:56:52:
: Once water gets into the dry pipe it will start siphoning out of the boiler. Believe me, you don't want water leaving the boiler via the steam header! Besides water hammer like you wouldn't believe, it could cause the steam line to rupture.
: For this reason our boilers are equipped with high level whistles and the automatic feedwater valves are set to fail CLOSED in the event of a loss of control. The thinking is that it is better to have the boiler shut down on low water than risk feeding water into the steam line!
I agree with Mike. FW control valves should be fail closed. You should have a LWCO and an aux LWCO. There are usually no safety procedures for high level.