The New York herald. [volume] (New York [N.Y.]) 1840-1920, 1873-01-04

pervtsinr Inspector of steam vessels-who has, OF
course, made steam and ali the freaks OF which 1t
is guilty o life study. The conversation began AZ
usual
"what do you Know about superhcated steam'"
swell. | know something, though do not, OF
course, pretend to be q very learned chemist.
am an engineer, and know chiefly
TIE PRACTICAL WORKINGS
o! the question"
sBut, of course, you believe in the existence OF
superhcated steam"
"There is such thing Of that there cannot be
the slightest doubt. l don't think, however, that
superheatng is seriously dangerous thing where
there Il free communication between the boiler
while 1t is still properly filed with water Steam,
dry and That cannot happen where fresh, moist
steam is constantly in circulation"
Mellow asSgs tSs required 10
''sUPERuEArED STEAM
is no denser than the, same body OF steam AZ
lower temperature, and, therefore, DO not see
very well how the pressure II exerts can DO
"Do you think that steam can be supcrheated SO
as to bring the pipes or tubes In which IL Is con-
fined to DANGEROUS degree OF heatr
al suppose it might, but only under rather ex-
ceptional circumstances. 1 certainly 40 not
believe in this vague theory propounded IN the
as 10 shut or the supply of heat: During the
war had vessels in charge which kept their
fires banked up for weeks together ana HsySr
if there be free communication with the boiler, as
| said before, don't think there can easily be
The reporter next called upon several engineers,
but they all seemed anxious to keep out OF the
being given that their names should not be men,
toned. Curionsly enough, too, all
APPEARED TO BE AGREED
In the opinion that the Fire Marshal had made
mistake, having been mised by some partial au-
thority
''Why just look at it," said one; ais 1t reasonable
to suppose that these steam heaters can be such
pregnant source OF peril as Is alleged Look over
the many establishments that are thus heated
the HERALD est adjustment itself for example. How
Is 1t that this discovery has been made SO late in
goes back Tor thirty years. and never found that
STEAM PIPES
were In any way source OF danger. 1t Is true
that the heat from steam pipes frequently makes
the surrounding wood very dry, and consequently
easily lnnammable, but the same might be said OF
stances the wood surrounding pipes to be to some
extent discOOred by Its proximity to the tubing.
But that is very rare-l have not seen 1t often, ny
:, aDo not the heating people freely pass steam
"Why, OF course they do, and without the faint
est qualm Of misgiving. In large manufactures
where the look OF the thing does not matter much,
the pipes are even fastened to the woodwork.
That would not be done II there was any suspicion
OF peril Besides, 1t would he very easy to devise
simple means OF protection"
'sThen you'do not believe in Mr.. Wards theory
OF superheated steamY"
81 believe in such thing, Of course, as super
heated steam, but do not think 1t likely to occur to
q dangerous extent wherever there Is free COM
muDicaton with the boiler. The steam must be
unless from the outside Of the pipes. And II so APP
piled, sufficient degree of heat would OF course,
as easily ignite the surrounding woodwork as bring
the steam to degree of heat sunlcent to heat the
pipes to the necessary point of iniammabity."
slow do you account for the starting OF this
swell, 1t may be honestly advanced, but between
ourselves don't mind telling you that think
THE INSURANCE COMPANIES
have something to do with 1T. ID lbs always Oecu
stated and believed that steam heating was one OF
the least dangerous forms of warming buildings,
and the rate or Insurance in such structures has
been proportionately moderate Now, fancy the
insurance companies sec their at the
present excitement. Their losses recently have
been very heavy and they feel more or less nervous
themselves safe would be to increase the rate OF
many Of their risks. You can't blame them either |;
1t is all in the way OF business"
The Fear About Steam-Hcating Appn-
ratus GrOundless.
| To THE EDITOR OF THE HERALD
The subject Of superheated steam as recently
presented in the public prints is well calculated to
| excite alarm in the minds OF many people other
wise intelligent, but who not well informed as
to the laws which govern the production Of steam
| or its use as motive power for warming build
| ings. The subject should be presented to their
minds in q simple and candid manner. It will not
help them to devote article to the demolition OF
| Fire Marshal McSpedon, whose principal fault Is
that he has attached to his practice, which has
been extensive, theory not only unnecessary. but
| incorrect and disturbing. He is not the only man
! whose observations are more valuable than his
| theories. Let us, therefore, endeavor to state
the facts OF the case generally under
stood by engineers and experts, always bear
ing In mind that we dealing with subject in
vOlyng remote laws. and wherein the best
|
Qualify an opinion. The numerous conflicting
theories as to the cause Of steam boiler explosions
should convince us that the subject affords room
for disagreement. Superheated steam may be
popularity defined as steam containing more heat
! than 1t would receive from the water from which
1t was generated or than is due to its pressure.
| law assumed as safe to depend upon is, that when
it Is always at temperature corresponding to Its
| density or pressure. When water In boiler boils
the temperature Is 2l2 degrees, and the pres
Raise the temperature to ZIG degrees
and we have one pound pressure to the
inch; to 2251l degrees, and we have four pounds
| to 235 degrees, seven and onehalf pounds; to $50
degrees. fourteen pounds; to 900 degrees, iorty-
eight pounds; TO 343 degrees one hundred pounds,
all these numbers being approximate, and so for
all intermediate pressures. Thus 1t will be seen
as wonS 9G hs
ably accurate gauge OF the pressure within the
boiler-in fact, 1t is oltentimes employed for that
purpose. The steam within such a boiler Is not SUI
perheated and cannot, SO lar as the practice OF
the world bears upon the point, be called danger.
Gus to the woodwork with which the boiler or
pipes may come into contact But now we reach
| q consideration which should be impressed upon
the minds Of all who wish to understand
the subject, as the one compromising Oil
the dangerous conditions, at least so far as the
communication OF fire to the adjacent woodwork
| Is concerned. We have steam within our boiler
of more less pressure, according to its tempera-
ture, and lying upon water thai is Of the same
| temperature. This steam Is q gaseous body, and,
| when separated from the water and exposed TO
heat obeys law entirely different from that
under which it was formed-in word, 1t Is practi-
cally like common air. 10 get even the moderate
pressure OF fifteen pounds per square inch upon a
boiler filled with air would require temperature
| OF about four hundred and eighty degrees. This
| wQull a OF