Improvements in Safety Valves for Steam Boilers.
Year: 1894

page_text: Date of Application, 13th June, 1894
Complete Specification Left, 12th Mar., 1895-Accepted, 13th Apr., 1895
PROVISIONAL SPECIFICATION.
Improvements in Safety Valves for Steam Boilers.
We JAMES ASHTON FLETCHER and SAMUEL FLETCHER, both of The
Borough Brass Works, Ashton under Lyne, in the County of Lancaster,
Brassfounders, do hereby declare the nature of this invention to be as follows:-
Our said invention relates to improvements in the valves described in the
Specification of our Patent No. 21075 of A.D. 1892.
The object of our present invention is to construct the valves in such a manner
that in the event of the valve "blowing off" it may be at once determined
whether the exit of steam is due to lack of water or to excessive pressure of steam
in the boiler.
For this purpose we introduce into the chamber above the valves partitions or
casings so arranged that part of the chamber which receives the steam escaping
from the low water valve is kept separate from that part which receives the steam
escaping from the high steam valve.
The outlets from the two chambers are arranged at different parts of the valve
casing, preferably on opposite sides thereof so that in the event of either valve
opening the person in charge may at once ascertain the cause by noticing the
outlet from which the steam is issuing.
Dated thin 10th dor of Lune 1804
E. T. WHITELOW, A.M. Inst. C.E.,
70, Deansgate, Manchester, Agent for the Applicants.
We JAMES ASHTON FLETCHER and SAMUEL FLETCHER, both of The
Borough Brass Works, Ashton under Lyne, in the County of Lancaster,
Brassfounders, do hereby declare the nature of this invention and in what manner
the same is to be performed to be particularly described and ascertained in and by
the following statement and accompanying drawings in illustration thereof:-
Our said invention relates to improvements in safety valves for steam boilers
for permitting the escape of steam in the event of the steam pressure rising or in
the event of the level of the water in the boiler descending below certain
predetermined points such as described in the Specification of our Patent
No. 21075 of A.D. 1892.
"
In such valves as heretofore constructed the steam escaping from either the
high steam valve or from the "low water "valve enters a common chamber
whence it passes to the open air.
In such a construction no indication is afforded whether the "blowing off" is in
consequence of excessive pressure of steam or lack of water.
The object of our said invention is to enable the attendant to at once determine
by the place of exit the cause of the escape of steam.
We introduce into the exit chamber above the valves partitions diaphragms or
division walls in such a manner that the part of the chamber which receives the
Posse Rd

page_text: steam from the low water valve is kept separate from that part of the chamber
which receives the steam from the high steam valve or valves.
Figs. 1 and 2 are respectively sectional and outside elevations of a compound
valve having only a single steam valve. Fig. 2 is a view at right angles to
Fig. 1.
a is the low water valve bis the high steam valve. c' is the chamber into which
the high steam escapes whence it emerges through the opening c. The part d of
the cover c which receives the steam from the low water valve is partitioned off
from the part c¹ by a partition d¹ preferably forming an integral part of the bonnet
or casting c which covers the valves and carries the weighted lever or spring of
the high steam valve.
Steam from the low water valve thus passes out at 2 through an outlet at right
angles to the outlet c³.
Fig. 3 is an elevation partly in section of a valve having two high steam valves
with a low water valve a lying between them.
Fig. 4 is a sectional plan through -y of Fig. 3.
In these figures the partition or curtain d³ separates the steam from the low
water valve a from the chamber e into which passes the steam from the two high
steam valves b. In this case the outlet from the "low water " valve is opposite
to the outlet for the "high steam
"
valves.
As will be well understood the shape and disposition of the divisions or partitions
may be varied according to the particular construction of valve to which our said
invention is applied.
In some cases distinct chambers or covers may be provided for the reception of
the steam from the high steam or low water valves.
We make no claim to the particular construction of the details of the valves
or to their mode of operation. These may be any of the usual well known types.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
"
1. A combined "low water " and "high steard safety valve baving a common
communication with the interior of the boiler under the valves and separate
chambers and outlets above the valves for the reception and release of the steam
when the valves open substantially as and for the purpose set forth and shown.
"
2. In a combined "low water" and "high steam" safety valve the use of
diaphragms divisions or partitions over the valves for the purpose of permitting
the egress of the steam from the "high steam
from that for the steam from the "low water
shown.
Dated this 11th day of March 1895.
"
valve through an outlet separate
valve substantially as set forth and
E. T. WHITELOW, A.M. Inst. C.E.,
70, Deansgate, Manchester, Agent for the Applicants.