Re: Pressure switch
Posted by: George Nutz (IP Logged)
Date: January 29, 2002 06:49PM
<HTML>Mark,
Thanks so much for the input. I have long suspected that a bourdon tube "spring" would have a lot of give and take to overcome the force it takes to operate a microswitch and the pressure differential it takes to overcome all of this---your 5% differential below 1000psi is not that bad. The present pressurestadt is of a bellows design that gives much more force differential per psi than the bourdon "spring". Have also thought of the cheap "Radio Shack" infrared sensors to remove the hysteresis/put a flag on the bourdon tube in the darkness of the insides---all this takes a lot of time however to futz with. 5% Ain't bad for a $50 unit!! At this time the bellows industrial unit we have(limited to 310psig) is as low as 15psi differential, when running the boiler at near maximum decreases the on-off times that helps the economiser and feedwater control system to maintain stability and good balance.
I thank all for there responses on this matter, Rod and I will move forward one way or the other on the Lamont boiler!
Best, George</HTML>