In a message dated 1/25/2007 12:19:53 P.M. Pacific Standard Time, [EMAIL PROTECTED] writes:
but I also could not 'see' if the sight glass was either all full or empty ??????? That is the same situation with the "big uns". I saw a main drum fried and sagged on a 1000 deg F and 1000 psi boiler when the operator could not tell if the glass was full or empty. He guessed wrong and blew off what he thought was excess water when the level was below the glass. The only thing you can see in a gauge glass is the water line. A full glass and an empty glass look the same so that is why a secondary level indicator is important. On the big ones we used "Three element" level controls. Not only measured the level of water in the drum, but also took into account steam flow to the prime mover and fuel flow into the burners. Take a drum or boiler full to the proper level and closed throttle. When you open the throttle the pressure will drop a bit which will cause the steam bubbles in the water to expand and give the gauge glass a reading of excess water, but that is wrong as you are losing water making steam leaving through the open throttle. So a skilled operator (or I imagine a computer now) keeps track of all the conditions going on inside the boiler and handles feed water appropriately. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://postfix.45mm.com/pipermail/sslivesteam/attachments/20070125/1d12f893/attachment.html _______________________________________________ SSLiveSteam mailing list Send messages: [email protected] Cancel subscription: http://postfix.45mm.com/mailman/listinfo/sslivesteam Rules: http://www.45mm.com/sslivesteam_guide.html
