Mechanical Contracting & Plumbing January-December 1909 . s to thevolume of water carried in the main hasarisen the use of mains of excessivesizes in many cases when as good if notbetter service could be had with mainsof much smaller size. Still at the sametime care is to be exercised in not toogreatly limiting the size of the main,especially if the main is of considerablelength. The ideal condition of operation withlow pressure steam heating is thatwhere just sufficient steam is evolved tomaintain steam in all the radiatorswithout the least pressure being shownon the steam gauge. Where the bo
Mechanical Contracting & Plumbing January-December 1909 . s to thevolume of water carried in the main hasarisen the use of mains of excessivesizes in many cases when as good if notbetter service could be had with mainsof much smaller size. Still at the sametime care is to be exercised in not toogreatly limiting the size of the main,especially if the main is of considerablelength. The ideal condition of operation withlow pressure steam heating is thatwhere just sufficient steam is evolved tomaintain steam in all the radiatorswithout the least pressure being shownon the steam gauge. Where the boileris of ample capacity, the draft good,and the piping reasonably well erectedit is just as easy, and in fact easier, tomaintain this condition than to oper-ate the fire so that at one time thereare three or four pounds of pressureshowing on the gauge and at othertimes not sufficient steam to supply allthe radiators. Water Leaving Gauge Glass. Occasionally with low pressure steamheating one meets with a most perplex-ing difficulty and that is where the. elbow. Some fitters claim the latter asbeing the preferable way, as it emptiesthe water more easily into the mainand gives drier steam, but general ex-perience hardly shows this to be thecase. This idea arises from a miscon-ception as to the volume of water thatis condensed from the steam in any6 water leaves the gauge glass on thewater column just as soon as a slightpressure is raised at the boiler. Thismay happen with as low as only a halfpound of indicated pressure, or may nottake place until there is one and ahalf or two pounds indicated rare cases it may happen before theneedle on the steam gauge has hardlyleft the pin or stop. This phenomenon is due to the differ-ence in pressure between the two ends January 15, 1909 PLUMBER AND STEAMFITTER of this system, together with the for-mation of a vacuum under certain con-ditions, and also by entrained watercarried over with the steam into thesteam main, due to the ve
Size: 2354px × 1061px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubject, booksubjectplumbing
