Washout Plugs, etc.
||Every boiler shall be fitted with
at least 3 brass wash plugs of not less than 25
mm. diameter which shall be screwed into the openings
in the shells near the bottom. In the boilers of
closed system type heated by removable internal
electric heating elements, the opening for these
elements when suitable for cleaning purposes may
be substituted for wash out openings.
||Boilers not exceeding 300 mm. internal
diameter may have two 25 mm. openings for cleaning
one of which may be used for the attachments of
the blow off valve. The openings shall be opposite
to each other, wherever possible. All threaded openings
in the boiler shall be provided with riveted or
welded reinforcement, if necessary, to give four
full threads therein.
||Electric boilers of a design employing
removable top cover flange for inspection and cleaning
need not be fitted with washout openings and washout
plug. Level gauges are not required for once through
||Every boiler shall
be provided with at least one feed pump or other feeding
device except where it is connected with a water main
carrying pressure to feed the boiler or where the steam
generator is operated with no extraction of steam (closed
system). In the latter case, in lieu of the feeding device,
a suitable connection or opening shall be provided to
feed the boilers. Such connection shall be not less than
13 mm. in diameter.
Subject to the provisions of this sub-regulation
every boiler shall be fitted with necessary mountings
and fittings as provided in Chapter
of these regulations, and they shall be of substantial
construction suitable for 7 kg/cm2
. All these fittings
except safety valves shall be certified by manufacturers
of the fittings themselves.
|The feed pipe shall be provided
with a check valve and a stop valve of a size not less
than that of the pipe. The feed water may be delivered
to the boiler through the openings of the same size in
the shell as that of the blow off connection.
|Each boiler shall be equipped
with a blow off connection, not less than 18 mm. in size
located to drain the boiler water from the lowest water
space practicable when the boiler is under pressure. Feed
water shall not be introduced through the openings or
connection needed for the water column, the water gauge
glass or the gauge cock.
|Every boiler other than a coil
type or a once through boiler shall be fitted with two
gauge glasses not less than 150 mm. long for determining
the water level. The boiler shall have the lowest visible
part of the water gauge located at least 25 mm. above
the lowest permissible water level.
The lowest permissible water level of vertical boilers
shall be at a point one-third of the height of the shell
above the bottom head or tube sheet. Where the boiler
is equipped with internal furnace, the water level shall
not be less than one-third of the length of the tubes
above top of the furnace tube sheet.
| The steam pressure gauge shall
have its dial graduated to not less than twice the maximum
allowable working pressure of the boiler. The diameter
of the dial shall be at least 100 mm. and the pipe connecting
the pressure gauge shall be minimum 10 mm. and the connection
shall be through siphon.
| Each boiler shall be equipped
with two safety valves for relieving the steam pressure.
The diameter of the valve shall not be less than 19 mm.
minimum relieving capacity of the safety valve shall be
sufficient to discharge all the steam that can be generated
by the boiler without allowing the pressure to rise more
than 10% above maximum allowable working pressure. The
safety valve shall be connected to the boiler independently
of any other steam connections, without any unnecessary
intervening pipe or fitting. Such intervening pipe or
fitting if unavoidable shall be not longer than the corresponding
face to face dimension of a tee fitting of the same diameter
and the minimum opening there through shall be at least
equal to the valve inlet.
No valve of any description shall be placed between safety
valve and the boiler not on the discharge pipe from the
safety valve to the atmosphere.
The electrically heated boilers shall be effectively earthed
with a lead of substantial cross section.