Every boiler shall be provided at least with the following:-
Two safety valves, one of which may be a high steam
and low water type safety valve. In no case should the
bore of the seat of the valve be less than 19 mm (¾");
Two means of indicating water level;
A steam pressure gauge;
A steam stop valve;
A feed check valve;
One feed apparatus. When the heating surface exceeds
200 square feet-two independent feed apparatus, each
such apparatus shall have a capacity of not less than
the maximum continuous rating of the boiler. (For boilers
in battery see regulation
A blow down cock or valve;
plugs as provided under Regulation 331;
An attachment for Inspectors test gauge;
A manhole, where size and construction permit, and such
mudholes or sightholes as are necessary for effectively
cleaning the boiler.
In the case of boilers fitted with integral superheaters,
an additional safety valve shall be fitted at the end
of the superheater outlet header.
In the case of boilers with no fixed steam and waterline,
the fitting of such accessories that are manifestly
not needed or used, such as water gauges, water columns
and gauge cocks, may not be insisted upon.
Two independent feed apparatus mean feed apparatus to
which power is supplied from two independent sources
or from a main or mains to which two sources of generation
are connected or from a common steam main fed by two
or more active boilers or, a combination of any of the
*NOTE.-It is recommended that in Lancashire and Cormish
Boilers one of the safety valves should be of high steam
and low water type. In Water Tube and Horizontal Multi-tubular
Boilers, a low water alarm directly operated by steam
should be fitted. Rams-bottom type safety valves consisting
of two valves and with spring and lever in common may
be considered as two safety valves for the purpose of
In the case of Marine Type boilers low water alarm may
be fitted in place of a fusible plug.
In the case of automatic or semi-automatic oil-fired
or gas fired boilers, low water alarms may be fitted
in preference to fusible plugs provided such boilers
are equipped with automatic tripping device to disconnect
fuel supply and to start the feed pump simultaneously
in the event of low water in the boilers.
In the case of a single boiler of the shell Type and
not connected in a battery with other boilers, the heating
surface of which does not exceed 102² (1,00 sq.
ft.), two independent source of power supply to the
two feed apparatus will not be necessary.
In the case of miniature boilers coming under Chapter
XIV the Steam pressure gauge may be connected to the
steam space or to a steam connection to the water column
by a syphon tube or equivalent device that will keep
the gauge tube filled with water. If brass or bronze
composition is used the minimum size of the syphon tube
shall be 6mm.(¼ in.) standard pipe size; for
other materials the minimum inside diameter of the pipe
or tube shall be 13 mm ( ½ in.).
For Electrode boilers, see Regulation