Improvements in Pressure Reducing Valves.
Year: 1896

page_text: Date of Application, 14th Dec., 1896
Complete Specification Left, 13th Sept., 1897-Accepted, 30th Oct., 1897
PROVISIONAL SPECIFICATION.
Improvements in Pressure Reducing Valves.
I, JOHN WHITEHEAD of Fiume, in the Kingdom of Hungary, Manufacturer, do
hereby declare the nature of this invention to be as follows:-
My invention relates to pressure reducing valves for variable admission pressures
and has for its object to provide a valve of this class which may be adjusted to
any desired constant pressure at the escape side thereof.
The improved valve comprises a suitable casing having within it a valve seat
and a valve secured to a piston tightly fitting a cylinder atttached to or forming
part of the valve casing. A rod bears with one end against the top of the piston
and is guided at the other end in a bracket secured to or forming part of the
valve case. A spring is inserted between the said bracket and a shoulder on the
said rod. The area of the cross section of the piston is slightly larger than that
of the valve.
Let P be the pressure at the admission end, p the pressure at tlie escape end,
Q the area of the cross section of the piston D and g the area of the cross section
of the valve and finally T the pressure exerted by the spring on the piston, then
the valve will be at equilibrium when::
P(Q-q) pq T.
Now if P diminishes then the piston will be forced downward by the spring and
the gas or air way controlled by the valve becomes larger so that the pressure
of the escaping gas or air becomes higher relatively to the admission pressure;
at the same time the tension of the spring is diminished as the spring expands in
forcing downward the piston; thus the piston and the valve come into a new
position of equilibrium and by suitably determining the dimensions of the spring
the piston and the valve it is easy to keep the pressure of the escaping gas
practically constant although the admission pressure may vary considerably.
Dated this 14th day of December 1896.

page_text: be performed to be particularly described and ascertained in and by the following
statement:-
My invention relates to pressure reducing valves for variable admission pressures
and has for its object to provide a valve of this class which may be adjusted to
any desired constant pressure at the escape side thereof.
In the accompanying drawings I have shown a vertical section of a valve con-
structed in accordance with my invention.
A is the valve casing, B the valve seat formed within the said casing, C is the
valve secured to a piston D fitting tightly in a cylinder E attached to or forming
part of the valve casing. G is a rod bearing with one end against the top of the
piston and guided at the other end in a bracket H secured to or forming part
of the valve casing. F is a spring inserted between the upper part of the said
bracket H and a shoulder on the rod G. The area of the cross section of the
piston D is slightly larger than that of the valve C.
Assuming P to represent the pressure at the admission end, is the pressure
at the escape end, the area of the cross section of the piston D, q the area of
the cross section of the valve C, and T the pressure exerted by the spring F on the
piston, then the valve will be at equilibrium when,
P(Q-q) +pg= T.
Now if P diminishes then the piston D will be forced downward by the
spring F and the gas or air way controlled by the valve becomes larger so that
the pressure of the escaping gas or air becomes higher relatively to the admission
pressure, at the same time the tension of the spring is diminished as the spring
expands in forcing downward the piston D; thus the piston and the valve come
into a new position of equilibriumi and by suitably determining the dimensions
of the spring the piston and the valve it is easy to keep the pressure of the
escaping gas practically constant although the admission pressure may vary
considerably.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what I
claim is :-
A pressure reduction valve comprising a valve casing with a valve seat, a valve
secured to a piston exposed to the admission, pressure a ovlinder in the valve casing
for the piston to slide therein the area of the piston being larger than that of the
valve and a spring acting on the said piston to open the valve, substantially as
and for the purpose described
Dated this 10th day of September 1897.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.