The Rules do
not cover all details of construction nor the proper proportioning of
parts, and devices which comply with these requirements alone are not
necessarily suitable for listing as permissible for use. These points are
often only developed in the examination required before permission is
given for installation.
_Class A.--Stationary Apparatus for Isolated Installations._
15. GENERAL RULES. GENERATORS.--(_a_) Must be made of iron or steel,
and in a manner and of material to insure stability and durability.
(_b_) Must be automatically regulated and uniform in their action,
producing gas only as immediate consumption demands, and so designed that
gas is generated without producing sufficient heat to cause yellow
discoloration of residuum (which will occur at about 500 deg. F.) or
abnormal pressure at any stage of the process when using carbide of any
degree of fineness.
The presence of excessive heat tends to change the chemical character of
the gas and may even cause its ignition, while in machines of the
carbide-feed type, finely divided carbide will produce excessive pressure
unless provision is made to guard against it.
(_c_) Must be so arranged that during recharging, back flow of gas
from the gasholder will be automatically prevented, or so arranged that
it will be impossible to charge the apparatus without first closing the
supply-pipe to the gasholder, and to the other generating chambers if
several are used.
Pages:
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300