CERTAIN IMPROVED APPARATUS FOR PREVENTING THE EXPLOSION OF STEAM BOILERS
Year: 1848

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWARD
WALMSLEY, of Heaton Norris, in the County of Lancaster, Cotton Spinner,
send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twenty-seventh day of April, in the cleventh year of Her
reign, and in the year of our Lord one thousand eight hundred and forty-
eight, did, for Herself, Her heirs and successors, give and grant unto me, the
said Edward Walmsley, Her especial license, full power, sole privilege and
authority, that I, the said Edward Walmsley, my executors, administrators,
and assigns, and such others as I, the said Edward Walmsley, my executors,
administrators, or assigns, should at any time agree with, and no others, from
time to time and at all times during the term of years therein expressed,
should and lawfully might make, use, exercise, and vend, within England
and Wales, and the Town of Berwick-upon-Tweed, my Invention of "CERTAIN
IMPROVED APPARATUS FOR PREVENTING THE EXPLOSION OF STEAM BOILERS;" in which
said Letters Patent is contained a proviso that I, the said Edward Walmsley,
shall cause a particular description of the nature of my said Invention, and
in what manner the same is to be performed, to be enrolled in Her Majesty's
High Court of Chancery within six calendar months next and immediately
after the date of the said in part recited Letters Patent, as in and by the
same, reference being thereunto had; will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, 1, the said
Edward Walmsley, do hereby declare that the nature of my said Invention,
and the manner in which the same is to be performed, is particularly
described and ascertained in, and, by the Drawings hereto annexed, and the
following explanation thereof (that is to say) :-.
My Improved Apparatus for Preventing the Explosion of Steam Boilers
consists,
First, in a certain novel arrangement of mechanism, designed for the
purpose of opening the sufety valve of steam boilers whenever the steam in
the same is raised beyond a certain density or pressure; and,"
Secondly, my Invention consists in an arrangement of mechanism for ad-
mitting a draught of cold air above the furnace, or closing the lamper in the
flue leading to the chimney, whenever the pressure of the steam increases
above a certain point, or the water falls below a certain level.
Such being the nature and object of my said Invention, I will now proceed
to describe the method of carrying the same iuto practical effect, which will be
easily understood upon referring to the Drawing accompanying these presents,
in which the boiler and the ordinary apparatus, connected thereto are repre-
sented as drawn in outline only,, whilst the new parts, or those constituting my
Invention, are shaded with color, for the sake of distinction.
Fig. 1 is an elevation of a low pressure steam boiler, with my.improved
apparatus shewn as attached thereto; and Fig. 2-a section of the same.
a, a, is the boiler supported in the brick work b, b, in the usual manner; c, c, is
the furnace or fireplace; d, d, are the flues; e, e, the "man-way"; and f.f, the
safety valve. It will be seen that the boiler a, a, is furnished with an upright
pipe 9, 9, extending downwards through the top of the boiler, and opening near
the bottom of the same, and likewise extending upwards several feet above the
boiler, as seen best in Fig. 4, which is a complete elevation of the apparatus
upon a reduced scale. The said pipe.g is isolated from the currents of water
in the boiler, (i. e.) kept in still water, by being placed within another pipe g*. g*,
of larger diameter (see Fig. 2)... The height of the pipe g, g, above the level of
the water must be so regulated, that when the steam in the boiler is of the
required density,. the pressure thereof shall cause, a column of water to ascend
the said pipe. nearly to the level of the horizontal pipe h, h, which connects the
pipe g,g..to the descending pipe i, i. The safety valve f,f, is connected by a
link k, k, to the lever 1, 1, which has its fulcrum at m, and carries at one end a
can or bucket n, which is furnished with a. valve, o, opening upwards. The
other end of the lever / is. counterbalanced, and the valve weighted to the
required pressure, by means of the weights p. p. The operation of this part of

page_text: the apparatus is as follows:-Suppose the pressure of the steam required to be
equal to about twelve pounds upon the square inch, then the end of the lever
, to which the valve is attached, must be weighted, so that when the steam
arrives at that density the lever will be balanced, or nearly so, and the height
of the pipe g. 9, above the water line must be such that the pressure of the
steam at that density will raise the column of water nearly to the level of the
horizontal pipe h, h. But us soon as the pressure of the steam increases, and
raises the column of water above that level, it will flow along the horizontal
pipe h; h, and descend the pipe i, i, (which is open to the atmosphere at the
top) into the bucket 1, the weight of the said water thus destroying the equi-
librium of the lever, and causing the other end thereof to rise and open the
safety valve. The bottom of the bucket is pierced with a small hole, so that if
only a small quantity of water descends the pipe i, i, it will all run out into the
cistern g, g, below, before the bucket has descended far, and thus allow it
almost immediately to resume its original position, but if a larger quantity of
water falls into the bucket n than can run out through the small hole, the bucket
still keeps descending until the tail of the valve o comes into contact with the
bottom of the cistern g. 9, which will open the valve and release the water, thus
allowing the bucket n to rise, and allow the safety valve to close.
The arrangement of mechanism for admitting cold air above the furnace, in
the event of the steam being raised to too high a pressure or the water falling
below its proper level, is as follows:-, r, is a flue opening above the dead
plate of the furnace, being closed at the top by a cover s. The covers of the
cold air flue is connected by a rod t to the lever u, the other end of the said
lever being attached to a float v in the boiler by the rod w. The lever u is
also connected by the pin x to the lever l. It will be evident, therefore, that
whenever the water falls below its proper level, the action of the float v will
cause the lever u to raise the cover s, and admit cold air above the furnace,
and that the motion of the lever l, occasioned by the descending of the bucket
n, will have the same effect. I would also remark that, if preferred, the
motion of the lever may be made to open or close the dumper y in the fluc
leading to the chimney,
Fig. 3 shews a modification of my Invention, which may be applied to high-
pressure steam boilers. It will be seen that in this arrangement it is not
necessary to carry the pipe g to any great height. At the upper end of the
pipe I employ a valve box z, having a valve inside, and weighted by a lever
1, 1, similar to an ordinary safety valve or otherwise, so that when the pressure
of the steam increases, the column of water will raise the valve, and flowing

page_text: down the pipe i, i, will open the safety valve by means of the lever 1, as in the
other arrangements.
Having thus described the nature and object of my said improvements,
together with the method of carrying the same into practical effect, I would
remark, in conclusion, that I claim as my Invention,―
First, the method of opening the safety valve of steam boilers, when the
steam is raised beyond a certain density or pressure, by means of a column of
water in the ordinary feed or other pipe, acted upon by the steam itself, and
also the method of closing the safety valve when the steam is reduced to its
ordinary working pressure, by stopping the flow of water from the boiler, and
by releasing the water from the bucket, thus making the apparatus in effect
self-acting.
Secondly, the self-acting method shewn and above described of admitting a
current of cold air above the furnace, whenever the water in the boiler falls
below its ordinary level, or the steam is raised beyond the density or pressure
desired.
In witness whereof, I, the said Edward Walmsley, have hereunto set my
hand and seal, this Twenty-sixth day of October, One thousand eight
hundred and forty-eight.