Improvements in Reducing Valves.
Year: 1893

page_text: Date of Application, 27th May, 1893
Complete Specification Left, 26th Feb., 1894-Accepted, 14th Apr., 1894
PROVISIONAL DILUIFICATION.
Improvements in Reducing Valves.
I, WILLIAM GLASS WRENCH of 27 Oswald Street, Glasgow in the County of
Lanark, Consulting Engineer, do hereby declare the nature of this invention to be
as follows:-
This invention has for its object to improve the construction and operation of
reducing valves or apparatus by means of which steam or other gaseous or fluid
pressures can be transformed from a higher to a lower pressure as required.
are
The improved apparatus consists essentially of two cylinders of unequal or
differentiated areas formed on and open to the steam pipe or passage each cylinder
being fitted with a piston or plunger whose end is exposed to the steam pressure
and which pistons are directly connected together by means of a beam lever after
the manner of weighing scales. Steam is first admitted to the small cylinder at
full pressure and on its way towards the discharge orifice it is also free to act on
the piston of the larger cylinder. The pistons being of unequal areas
balanced by proportionately unequal pressures. Any variation therefrom upsets
this equilibrium the pistons moving accordingly and simultaneously in opposite
directions opening or closing their respective port areas on which they are free to
traverse. The larger by its lever connection with the smaller piston performs the
important double function of admitting or cutting off its own steam supply to just
what it requires and converts its cylinder into either an expanding or a contracting
chamber whose capacity accommodates itself to the volume at the reduced pressure
required. A delicate balance is thus obtained without the use of the ordinary
seating valves, springs, diaphragms or anything liable to derangement. The pistons
are each by preference formed with a projecting lip extending towards and
traversing the steam port so as to act as slide valves. Apart from the relative
pressures due to cylinder areas a wider ratio can be obtained under the invention
by altering the leverage i.e. by shortening or lengthening the distance from beam
fulcrum to centres of piston pressure at beain ends for which provision is accordingly
made by means of a moveable head at each end of the beam as well as by actual
transference of beam fulcrum from one point to another.
In the arrangement
described the pressures are on similar sides of the pistons and the links connecting
same to beam are in compression but a reverse construction may be adopted.
Dated this 26th day of May 1893.
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow, Agents.
Improvements in Reducing Valves.
I, WILLIAM GLASS WRENCH of 27 Oswald Street, Glasgow, in the County of
Lanark, Consulting Engineer, 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 :—
.
This invention has for its object to improve the construction and operation of
reducing valves or apparatus by means of which steam or other gaseous or fluid
pressures can be transformed from a higher to a lower pressure as required.

page_text: The
The improved apparatus as illustrated in vertical section at Figure 1 in plan at
Figure 2 and in detail at Figure 3 of the accompanying drawings consists essentially
of two cylinders A, B of unequal or differentiated areas formed upon and open to
the steam pipe or passage the cylinders being fitted with pistonus or plungers CD
whose ends are exposed to the steam pressure and which pistons are directly
or lever E after the manner of
connected together by means of a beam
weighing scales. Steam is first admitted to the small cylinder A at full pressure
and on its way towards the discharge orifice F it is also free to act on the piston of
the larger cylinder B. The pistons being of unequal areas are balanced by
proportionately unequal pressures. Any variation therefrom upsets this equilibrium
the pistons moving accordingly and simultaneously in opposite directions opening or
closing their respective ports G, H, over which they are free to traverse.
larger piston D by its lever connection with the smaller piston C performs the
important double function of admitting or cutting off its own steam supply to just
what it requires and converts its cylinder into either an expanding or a contracting
chamber whose capacity accomodates itself to the volume at the reduced pressure
required. A delicate balance is thus obtained without the use of the ordinary
seating valves, springs, diaphragms or anything liable to derangement.
pistons C, D, are by preference formed with projecting lips I, J, extending
towards and traversing the steam ports so as to act as slide valves. Apart from
the relative pressures due to cylinder areas a wider ratio can be obtained under
the invention by altering the leverage i.e. by shortening or lengthening the distance
from beam fulcrum to centres of piston pressure at beam ends for which provision
is accordingly made by means of a movable head K at each end of the beam as
In the arrangement
well as by actual transference of beam fulcrum from a to b.
described the pressures are on similar sides of the pistons and the links
connecting the same to the beam are in compression but a reverse construction
may be adopted.
The
The apparatus is by preference covered over with a hood L from which any
piston leakage may be drained away, or it may be open internally to the reduced
pressure side.
Auxiliary caps may also be fitted on the hood or cover for
convenience of relative pressure adjustment and the whole apparatus completed
with safety valve and pressure gauge, if required. It is obvious this arrangement
lends itself to various modifications of detail.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
1. A reducing valve constructed and arranged to operate substantially as
described.
2. In a reducing valve of the type set forth the combination with a steam
passage of differentiated cylinders formed therein and pistons connected together
and adapted to serve as valves to more or less close said passage substantially as
described.
Dated this 24th day of February 1894.
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow, Agents.