The star. (Reynoldsville, Pa.) 1892-1946, 1902-04-16
WHY BOILERS EXPLODE.
An Old Engineer Gives the Result OF Hts
Experience.

Experience.
why do boilers burss?" repeated All
OLD engineer, of whom the question
was asked. "Well. boilers are like
people. in that when they are ill-treat-
ed they get red-hot and explode.
THE principal cause of explosions Is
because of insufficient water in the
boiler. The water nust be kept above
the tubes, so that 1t nay boil freely.
When II falls below the tubes, the
boiler becomes red-hot. the steel pla1es
soften, expand and crack. and. swish.
up she goes. and all else in the imme.
date vicinity.
THE number OF boiler explosions in
different parts o. the country lately
calls to mind the constant menace to
human life and property existing lit
orally under our very feet, as Il is In
Easements and under the sidewalks,
where most of the boilers are situated
The great wonder is that more do not
go up in the air. incidentally carrying
the building and its contents of the
sidewalk with them. | saw the wreck
age caused by the fatal boiler explc-
sion in Pittsburg recently. Tho build
ing was complet, ly demolished, an
the ruins looked as though the build
ings had been blcwr to pieces, and ,he
around loycled by dynamite.
Boilers also burst where they have
flaws and unseen detects in 'oh metal
which will not stand the strain of the
pressure of the steam, and thep laces
part at this particular spot. Inspec-
tions often fail to reveal these laws
with terrible results. Cold water let
into the boiler when It Is hot and when
there Is no water or insufficient water
inside often means an explosion. The
steam Is generated so rapidly. and its
force is so terrific that the plates part
like pieces of paper. In the iron re-
gion the sulphur in the water used has
eaten the bolts off boilers [ have at
tended inside of three months. and
great care as to their repair in season
had to be exercised. Scales will also
form on the tubes. and when thickened
80 that the steel becomes red hot at
this point, but the water cannot get to
the metal becaus eof the scale. these
'blisters' part and an explosion re-
suits.
''In some of the big department
buildings in Washington the boilers
are fired to only about one-siXth of
their tensile strength. and boilers with
a licensed capacity of withdrawing l2G
pounds of steam pressure TO the square
inch, carry only from 30 to 100 pounds.
the safety valves being set at the lat,
ter figure. When the safety valves
work all right vent for the danger
pressure is permitted. but when they
don't, as is sometimes the case-well,
you will learn al about it when you
wake up the next minute in the other
world.
Boilers are better made now than
formerly. and are constructed Of steel
instead of iron, as long ago. The boil
er steel is tested to withstand a tensile
strain of 10000 pounds to the square
inch. as against 10000 pounds of a
generation ago. Boiler explosions,
while frequent enough now. do not
compare in number as at that period
There is more perfect system of in
spection and better class of men IN
charge. who are required to pass an ex-
animation and receive licenses before
they are allowed to run stationary en-
gines. as my remarks do not apply to
the boilers of locomotives. s."-Washing-
ton Star.