The extent of this loss of energy in a given length of pipe or in a meter
is measured by the difference between the pressures of the gas at the two
ends of the pipe or at the inlet and outlet of the meter. This difference
is the "loss" or "fall" of pressure, due to friction or work performed,
and is spoken of as the "actuating" pressure in regard to the passage of
gas through the stretch of pipe or meter. It is a measure of the energy
absorbed in actuating the meter or in overcoming the friction. (Cf.
footnote, Chapter II., page 54.)
DIMENSIONS OF MAINS.--The diameter of the mains and service-pipes for an
acetylene installation must be such that the main or pipe will convey the
maximum quantity of the gas likely to be required to feed all the burners
properly which are connected to it, without an excessive actuating
pressure being called for to drive the gas through the main or pipe. The
flow of all gases through pipes is of course governed by the same general
principles; and it is only necessary in applying these principles to a
particular gas, such as acetylene, to know certain physical properties of
the gas and to make due allowance for their influence.
Pages:
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462