Improvements in and relating to Safety Relief Pressure Valves.
Year: 1890

page_text: Date of Application, 18th June, 1890
Complete Specification Left, 16th Mar., 1891-Accepted, 30th May, 1891
PROVISIONAL SPECIFICATION.
Improvements in and relating to Safety Relief Pressure Valves.
I, ALEXANDER STEVEN, of the firm of A. and P. Steven Engineers, Provanside
Engine Works, Glasgow, Lanarkshire, do hereby declare the nature of my
invention to be as follows:-
This invention has reference to and comprises a new or improved mode of, and
means or construction and arrangement and combination of the parts of hydraulic
valves and fittings for relieving the pressure and preventing concussion and breakage,
and leakage at joints, in main and service water pressure pipes, and which will be
self closing and adjusting, and applicable for being placed locally on the pipes near
where concussions occur, as where the pressure is suddenly relieved or put off and
on by the opening and shutting of drawing off valves; and be more efficient for the
purpose than the air vessels and other appliances heretofore in use.
The nature and novelty of the improvements consist in the construction of a
cylindrical stand valve chest with open branch and flange below for attaching to
the mains or service pipes where the concussions are required to be stopped. This
lower branch would be formed with a turned valve seat for a brass or other metal,
leather, rubber or other equivalent, faced valve to close on, fitted on the lower end
of a hollow spring loaded cylindrical stem which would preferably be turned and
fitted into a bored part of the valve chest above; and this branch and the valve
when raised would open into a small lateral branch leading to an escape pipe jointed
thereto, sufficient to relieve the pressure when shocks and concussions occurred, and
be closed again by the loaded spring as hereinafter described. The upper close
end of this valve chest would be bored and fitted with a cup washer or other
equivalent hollow piston mounted over and embracing the upper end of a helical or
spiral spring of round or square section having its lower end fitted in the cup stem
of the valve, the spring being of sufficient strength to load the valve to the
desired pressure to sustain the normal or maximum pressure desired within the
main or service pipe. For the better adjustment of the pressure on this spring
and valve, a screw stud would be fitted in the centre of the upper close end of
this spring valve chest, with jam nut outside, so that by screwing in this stud,
the piston would be screwed down on the spring to the desired pressure and
fixed there, leaving a slight water space between the piston and the close end, with
a small lateral port leading into a small vertical channel formed down through the
web or body of the valve chest and entering into the open branch below the
loaded valve closing seat. This upper port is fitted from the outside with a lateral
conical pointed screw stem or valve in line with the port, to regulate a small slow
admission and emission of the pressure water from below the closing valve up into
the space above the piston, so that in the normal state of the valve the pressure
within the main and service pipes would act on the piston and upper end of the
spiral loaded spring, and so to a certain extent equalise the pressure downwards on
the spring and valve, and enable any extra pressure by concussion within the pipe
to open the lower valve and relieve the pressure through the escape branch, and
then gradually act on the upper piston again through the vertical side branch and
lateral port at top, to re-adjust the full pressure and close the valve after having
relieved it, and prevented the concussion of the water within the pipes.
A small hole would preferably be bored through the hollow stem of the lower
valve to permit of the escape of any water therefrom which might pass the upper
piston and collect there around the pressure spring, into the lateral escape pipe
above the valve; and a short glass tube would preferably be fitted between this
ateral escape branch and the drain pipe to be able to see the escape of the water

page_text: at each action of the relief valve. And this relief pressure valve might be used by
itself for the said purpose, or in combination with a close air pressure chamber,
such as those used with pumps.
Dated the 17th Luno 1900
W. R. M. THOMSON & Co.,
Agents.
COMPLETE SPECIFICATION.
Improvements in and relating to Safety Relief Pressure Valves.
I, ALEXANDER STEVEN, of the firm of A. and P. Steven, Engineers, Provanside
Engine Works, Glasgow, Lanarkshire, do hereby declare the nature of my inven-
tion and in what manner the same is to be performed to be particularly described
and ascertained in and by the following statement in writing, that is to say :-
This invention has reference to and comprises a new or improved mode of, and
means or construction, and arrangement and combination of the parts of hydraulic
valves and fittings for relieving the pressure and preventing concussion and
breakage, and leakage at joints, in main and service water pressure pipes and
which will be self closing and adjusting, and applicable for being placed locally on
the pipes near where the concussions occur, as where the pressure is suddenly
relieved or put off and on by the opening and shutting of drawing off valves; and
be more efficient for the purpose than the air vessels and other appliances hereto-
fore in use.
And in order that my said invention and the manner of performing or carrying
the same into effect or practice may be properly understood 1 have hereunto appended
an explanatory sheet of drawings in which the same reference letters are used to
indicate corresponding parts.
Figure represents a sectional elevation and
Figure 2 a plan view of a safety relief pressure valve as constructed in accordance
with my improvements.
Referring to these drawings,-The improvements consist in the construction of a
cylindrical lower or stand valve chest A with open lateral branch A' on one side
above the valve, and branch and flange A" below for attaching to the mains or
service pipes where the concussions are required to be stopped. This lower
branch A is formed and fitted with a turned valve seat A, and lift valve A³
made of brass or other metal, or it might be fitted with leather, rubber or other
equivalent bearing surfaces to close on, fitted under the lower end of a hollow
spring loaded cylindrical stem B, which would preferably be turned or have the
upper end or stem A of the valve A³ turned to work in a bored part A of
the valve chest 'A above; and the valve A³ when raised would open into the small
lateral branch A, leading to an escape pipe C jointed thereto, sufficient to relieve
the pressure when shocks and concussions occurred, and be closed again by the
loaded spring B' as hereinafter described. The upper cylindrical part A of this
valve chest is bored and fitted with a cup leather washer or other equivalent hollow
piston B and the cylinder preferably lined with brass with an inverted metal cup
mounted over and embracing the upper end of the helical or spiral spring Bof
round or square section having its lower end B fitted in the cup stem. A of the
valve A³, the spring B' being of sufficient strength to load the valve A3 to the
desired pressure to sustain the normal or maximum pressure desired within the main
or service pipe and branch A". For the better adjustment of the pressure on this
spring B and valve A³, a screw stud B is fitted in the centre of the upper close
end of this spring valve chest, which may have a jam nut outside, so that by
screwing in this stud B" the piston B³ would be screwed down on the spring B
to the desired pressure. and fixed there, leaving a slight pressure water space at B
between the piston B2 and the close upper end of the cylinder A', above the
piston B2 with a small lateral port a leading into a small vertical channel a' formed

page_text: down through the web or body parts A, A, A, of the valve chest and entering at a"
into the open pressure branch A" below the loaded valve A³. This upper port a
is fitted from the outside with a lateral conical pointed screw stem or valve a² in
line with the port a to regulate a small slow admission or emission of the pressure
water from below the closing valve A³, up into the pressure space B³ above the
piston B', so that in the normal state of the valve A³, the pressure within the main
and service pipes A", would act on the valve A³ and on the upper end of the
piston B and spiral spring B' and thus adapt the load on piston and spring to suit
the existing pressure within pipes whatever this variable pressure might be, and
still enable any extra pressure by concussion within the pipe A" to open the lower
valve A and relieve the pressure through the escape branch A' and outlet pipe C
and then again gradually act on the upper piston B through the vertical side
branch a' and lateral port a at top, to re-adjust the full pressure and close the valve A³
after having relieved it and prevented the concussion of the water within the pipes.
The small channel a' would preferably also have a screw plug B in its upper end
for cleaning it out. The upper end or stem A" of the valve A³ would be formed
hollow or open to permit of the escape of any water which might pass the upper
piston B2 and collect there around the pressure spring, into the lateral escape
pipe A above the valve A³; and a short glass tube C₁, is preferably fitted between
this lateral escape branch A¹ and the drain pipe C to be able to see the escape of
the water at each action of the relief valve. And this relief pressure valve chest
might be used by itself for the said purpose of reducing the concussions in mains
or service pipes or in combination with a close air pressure chamber such as those
used with pumps.
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 :-
First. The construction or arrangement and combination of the parts of a safety
relief pressure spring valve chest with piston in close cylinder above in commumi-
cation with pressure pipes for relieving the pressure and preventing concussion
in main and service pipes, substantially as herein described, in reference to and
shown in the accompanying drawings.
Second. The construction of safety relief pressure valve chests with outlet spring
loaded valve and piston with close pressure space above and setting regulating pin
or valve open to pressure below main valve, substantially as and for the purposes
herein described, in reference to and shown in the accompanying drawings.
Third. The construction of safety relief pressure valve chests, loaded with
pressure spring and piston with pressure space above, in connection with the pressure
pipes below valve, for giving to the piston and valve the variable pressure within
the pipes in addition to the pressure on spring, substantially as and for the purposes
herein described in reference to and shown in the accompanying drawings.
Dated the 14th March 1891.
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.