FIRING BOILERS NEWLY SET, ETC.—Boilers newly set should be heated up
very slowly indeed, and the fires should not be lighted under the
boilers for at least two weeks after setting, if it is possible to wait
this length of time. This two weeks enables all parts of the mason work
to set gradually and harden naturally; the walls will be much more
likely to remain perfect than when fires are lighted while the mortar
is yet green.
When fire is started under a new boiler the first time, it should
be a very small one, and no attempt should be made to do more than
moderately warm all parts of the brick work. A slow fire should be kept
up for twenty-four hours, and on the second day it may be slightly
increased. Three full days should elapse before the boiler is allowed
to make any steam at all.
When the pressure rises, it should not be allowed to go above four or
five pounds, and the safety valve weight should be taken off to prevent
any possibility of an increase. Steam should be allowed to go through
all the pipes attached for steam, and blow through the engine before
any attempt is made to get pressure on them. The object of all these
precautions and this care is to prevent injury by sudden expansion,
which may cause great damage.