An Improved Pressure Reducing Valve.
Year: 1888

page_text: Date of Application, 1st Aug, 1888
Complete Specification Left, 1st May, 1889-Accepted, 28th Sept., 1889
PROVISIONAL SPECIFICATION.
An Improved Pressure Reducing Valve.
JAMES JOHN PEARSON, No. 7, Side, Newcastle-on-Tyne, Mechanical Engineer, and
TOM HENRY TAYLOR, Norwood House, Heaton, Mechanical Engineer, do hereby declare
the nature of this invention to be as follows :-
"
An improvement in the device whereby the pressure of Steam or other Gas is
reduced by a Valve to any required amount, the same being known as a Reducing
Valve.".
'
The arrangement consists of a metal Valve box, having three or more orifices (A. B. C.)
& contains a piston (P) free to move in a chamber suitably prepared to receive the
same. Secured to Piston (P) by a rod (R) is a metal "Disc" or "Mushroom"
Valve (V) fitted to close tightly over the mouth of Chamber which contains Piston (l').
The Rod (R) securing Piston (P) to Valve (V) is continued thro' the end or cover of
Valve box, & is screwed to permit the adjustment of a Hand-wheel (H) which is
similarly screwed to fit rod (R).
Round the Rod (R) & between the Hand-wheel (H) & Valve box is placed a helical
spring (S) so arranged that when the Hand-wheel (H) is operated to advance down
the screwed end of rod (R) it will compress the Spring (S) which reacting against
Hand-wheel (H) lifts Valvo (V) from its Seat, thus admitting above Valve (V) the
Steam or Gas whose pressure it is required to diminish. In operation, when by means
of the Hand-wheel (H) the Valve (V) is lifted from its Seat the Steam or Gas issues
from the orifice (B)-which is in connexion with the Boiler or other generator of
pressure & the height of the lift of Valve (V) determines the outlet pressure thro'
the orifice (C) of the Steam or Gas that is passing. The lift of the Valve (V) having
been adjusted to secure the required pressure, this pressure remains constant, & is not
affected by the fluctuations of pressure in the Main Generator, for with Valve (V)
lifted & Steam or Gas above it, there is an equivalent pressure acting thro' piston (P)
against spring (S) & against the prossure of the atmosphere inletted thiro' orifice (A).-
Thus the piston (P) is operated by the mean of all the forces, & will lift or lower
Valve (V) as the pressure in the Generator falls or rises.-Thus securing an equal &
steady outlet Pressure.
No. Il, is an alternative design of No. I, identical in action when in operation, & in
description the index letters are common to both.
Dated this 31st of July 1888.
COMPLETE SPECIFICATION.
An Improved Pressure Reducing Valve.
We, JAMES JOHN PEARSON, No. 7 Side Newcastle on Tyne Mechanical Engineer,
and TOM HENRY TAYLOR of Norwood House Heaton Newcastle on Tyne, Mechanical
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 relates to Improvements in the construction of reducing valves such
as are employed for the purpose of supplying steain and other fluids at a pressure
below that of the generator or source of pressure.
We will describe our Invention with reference to the drawings filed with our
Provisional Specification and which represent in vertical longitudinal section two
forms of a valve constructed according to these Improvements.

page_text: In each of the Figures similar parts are denoted by similar letters of reference.
The valve box or casing is provided with three orifices A, B and C. Of these
openings A is an air inlet, B is the inlet for the high pressure fluid, and C is the
outlet for the low pressure fluid. The valve casing contains a
cylindrical chamber
within which there is fitted a piston P. This piston is connected by means of a
suitable rod with a disc or mushroom valve V, constructed and fitted to be capable of
closing the end of the cylindrical chamber containing the piston. The piston rod R is
of such a length that it will project through a suitable opening in the valve box or
casing for a sufficient distance to be operated on by a helical spring S. The rod R
has mounted on it a flange or collar, against which one end of the spiral spring S
abuts. The other end of the spiral spring may abut upon the valve casing as in Fig. 1
or against an adjustable stop or plate as shown in Fig. 2.
We usually prefer to adopt the construction and arrangement represented by Fig. 1.
According to this arrangement, the upper part of the piston rod is screwed to engage
with a female screw formed through the eye of the hand wheel H. The lower face of
the boss of this hand wheel is in contact with the upper face of the collar or flange
against which the upper end of the spiral spring abuts, and the collar or flange is
capable of being moved longitudinally along the piston rod R. It will be evident
that in this arrangement the hand wheel may be constructed to act as the collar or
flange, which may then be omitted. When the hand wheel is operated to advance
down the rod R, the spiral spring S is compressed and the valve V will be opened.
Since the high pressure fluid is admitted to the apparatus through the opening B
which is situated between the piston and the valve, the opening of the valve allows the
passage of the fluid to the low pressure exit. The high pressure fluid on the con-
trary, acting directly upon the piston, the other side of which is open to the air, tends
always to close the valve and to prevent the passage of the fluid. By operating the
hand wheel therefore so as to compress or to expand the spiral spring, the balance of
forces determines the outlet pressure of the fluid within any limits less than the
pressure of the high pressure fluid, and this pressure will remain constant and un-
affected by any variations in the pressure on the generator side of the apparatus.
In the valve shown in Fig. 2, the position of the valve V is.inverted. This involves
also an inversion of the piston and of the spiral spring, and the-hand wheel may be
dispensed with. The upper end of the spiral spring abuts against a plate or cross
piece between two rods, the upper ends of which are screwed and the lower ends of
which are secured to the valve casing. The upper ends of the rods pass through holes
in the abutment for the upper end of the spiral spring, above which they are fitted
with nuts. When the nuts are screwed downwards, the spiral spring is compressed
between the upper abutment and the flange or collar on the piston rod. The opera-
tion of the apparatus is therefore identical with that described with reference to
Fig. 1.
In Fig. 1, the piston rod passes through a part of the valve casing with which the
fluid is in contact when the apparatus is in use and we therefore provide a stuffing
box X or other equivalent means for preventing the escape of the fluid. In the modi-
fication shewn in Fig. 2, the piston rod passes through a part of the valve casing to
both sides of which the air has access, and there is therefore no necessity for the
stuffing box which is consequently omitted.
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 :-
A reducing valve, constructed and arranged substantially as herein before described
with reference to the accompanying drawings.