RELIEF VALVE FOR STEAM ENGINE CYLINDERS
Year: 1885

page_text: I, JOHN HENRY JOHNSON, of 47 Lincolns Inn Fields in the County of
Middlesex, Gentleman, do hereby declare the nature of said Invention for a
"RELIEF VALVE FOR STEAM ENGINE CYLINDERS," which invention has been
communicated to me from abroad by Thomas Mara Fell, Mining and Consulting
Engineer, resident of Brooklyn, Kings County, New York, United States of
America, to be as follows:-
This Invention relates to the relief valves that are used in connection with
steam-engine cylinders to prevent the evils arising from over compression and
water condensation.
One or more relief valves consisting each of a valve held to its seat by a spring
the pressure of which is somewhat greater than that of the steain in the engine
cylinder, are connected by pipes with the ends of the cylinder. The seat of the
valve, or seats of the valves, is or are placed below the opening in the end of the
cylinder, and the apparatus is so constructed that there are closed passages
between the valve or valves and the cylinder. These passages become filled
with water, portions of which are from time to time forced out through the relief
valve, when the pressure in the cylinder overcomes the tension of the spring
which holds the valve to its seat. This excess of pressure occurs after the slide
valve or its equivalent has closed the exhaust, and is due to the compression of the
confined steam and water by the piston which does not reach the end of its move-
ment until after the slide valve has closed the exhaust. It is preferred so to
adjust the spring tension that the valve will be lifted slightly at each stroke of the
piston. A projecting rod attached to the valve makes evident the movements of
the latter, and the tension of the spring is adjusted by a screw plug, which forms a
bearing for one end of the spring and through which the rod passes.
A cord may
be attached to this rod so as to lift the valve by hand when desired.
It is preferred to have enlargements or chambers in the pipes leading from the
ends of the cylinder in order to maintain a larger volume of water between the
relief valve and the cylinder-A pet cock is also placed below the relief valve or

page_text: below each relief valve where more than one are used, between it and the cylinder,
in order to drain the water therefrom.
My correspondent has devised two forms of relief valve apparatus.
In one form there is a single relief valve connected with both ends of the engine
cylinder, and check valves are placed in the connecting pipes-In the other there
are two relief valves, each controlling the discharge of water from its own end of
the cylinder.
In the double valve apparatus it is preferred to use a common discharge chamber
in which the two valves are placed.
The particular construction of the relief valves may, of course, be various. In
the single valve apparatus there may be used a piston valve with a hollow stem
guided by a portion of the valve chamber which projects into the discharge
.chamber, the relief spring (a spiral compression spring) being placed in the hollow
stem around a central projecting guide rod, and bearing against a screw plug in the
top of the spring chamber. The seat of this valve is made in one piece with the
discharge chamber.
-
In the double apparatus an improved construction may be employed which may
be applied to the single valve apparatus. The valve seat is made of a bushing
screwed to the bottom of the valve chamber, and projecting inside so as to give
metal for wear. This bushing is made of soft metal, say brass, while the valve is
made of harder metal or bronze. The valve has two stems on the bottom of the
valve disk, a fly stem below; which is guided in the bushing on the top of the
valve disk; a solid cylindrical stem which is guided in a contracted neck of
the spring chamber, which projects into the discharge chamber-On top of the
upper or solid valve stem is a disk, against which the relief spring presses. At the
top of the spring chamber is the screw plug, forming a bearing or point of resistance
to the relief spring.
A rod fixed at its lower end in the disk on the solid valve stem, passes through
a stuffing box in this screw plug; or there may simply be a hole through the screw
plug closed by a smaller screw plug, which can be removed for insertion of a wire
to rest upon the said disk.

page_text: I JOHN HENRY JOHNSON of 47 Lincolns Inn Fields in the County of
Middlesex Gentleman do hereby declare the nature of said Invention for a
"RELIEF VALVE FOR STEAM ENGINE CYLINDERS" which Invention has been
communicated to me from abroad by Thomas Mara Fell Mining and Consulting
Engineer resident of Brooklyn Kings County New York United States of America
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 the Relief valves that are used in connection with
steam Engine Cylinders to prevent the evils arising from over compression and
water condensation.
One or more relief valves consisting each of a valve held to its seat by a spring
the pressure of which is somewhat greater than that of the steam in the Engine
Cylinder are connected by pipes with the ends of the Cylinder-The seat of the
valve or seats of the valves is or are placed below the opening in the end of the
Cylinder and the apparatus is so constructed that there are closed passages between
the valve or valves and the Cylinder-These passages become filled with water
portions of which are from time to time forced out through the relief valve when
the pressure in the Cylinder overcomes the tension of the spring which holds the
valve to its seat-This excess of pressure occurs after the slide valve or its
equivalent has closed the exhaust and is due to the compression of the confined
steam and water by the piston which does not reach the end of its movement until
after the slide valve has closed the exhaust. It is preferred so to adjust the spring
tension that the valve will be lifted slightly at each stroke of the piston A
projecting rod attached to the valve makes evident the movements of the latter
and the tension of the spring is adjusted by a screw plug which forms a bearing
for one end of the spring and through which the rod passes-A cord may be
attached to this rod so as to lift the valve by hand when desired.
It is preferred to have enlargements or chambers in the pipes leading from the
ends of the cylinder in order to maintain a larger volume of water between the
relief valve and the cylinder-A pet cock is also placed below the relief valve or
below each relief valve where more than one are used, between it and the cylinder,
in order to drain the water therefrom.
My Correspondent has devised two forms of relief valve apparatus.
In one form there is a single relief valve connected with both ends of the engine
cylinder and check valves are placed in the connecting pipes-In the other there
are two relief valves each controlling the discharge of water from its own end of
the cylinder.
In the double valve apparatus it is preferred to use a common discharge chamber
in which the two valves are placed.
}
The particular construction of the relief valves may of course be various-In
the single valve apparatus there may be used a piston valve with a hollow stem
guided by a portion of the valve chamber which projects into the discharge
chamber, the relief spring (a spiral compression spring) being placed in the hollow
stem around a central projecting guide rod and bearing against a screw plug in the
top of the spring chamber-The seat of this valve is made in one piece with the
discharge chamber.

page_text: In the double apparatus an improved construction may be employed which may
be applied to the single valve apparatus. The valve seat is made of a bushing
screwed to the bottom of the valve chamber and projecting inside so as to give
metal for wear-This bushing is made of soft metal say brass, while the valve is
made of harder metal or bronze:-The valve has two stems on the bottom of the
valve disk a fly stem below, which is guided in the bushing on the top of the valve
disk: a solid cylindrical stem which is guided in a contracted neck of the spring
chamber which projects into the discharge chamber On top of the upper or solid
valve stem is a disk; against which the relief spring presses. At the top of the
spring chamber is the screw plug, forming a bearing or point of resistance to the
relief spring.
A rod fixed at its lower end in the disk on the solid valve stem passes through a
stuffing box in this screw plug or there may simply be a hole through the screw
plug closed by a smaller screw plug which can be removed for insertion of a wire
to rest upon the said disk.
In the accompanying drawings Figures 1 and 2 represent that form of apparatus
in which a single relief valve is connected with both ends of the engine cylinder,
Figure 1 being a vertical section of the apparatus, as applied to an upright cylinder
and Figure 2 an elevation shewing its application to a horizontal cylinder. Like
letters indicate like parts in these two figures.
A is the steam engine cylinder: B. a pressure regulating piston valve cylindrically
turned and fitting into the chamber C. in which it moves vertically and is further
held in position by the piston rod D, which is screwed into the bottom of said
piston B-The rod D is provided outside the chamber C. with a hook for attaching
a cord or some similar operating means so that the valve can be lifted when
desired and on the release of the cord will return to its former position. D¹ the
seat of the valve: E the outer or relief chamber having an exhaust port, F; G the
regulating screw plug; H the compression chamber in which are two valves 1 and 2
operated by a hinged joint and both opening inward and placed at an angle so as
to insure a proper setting on the seat, This chamber is placed below the relief
chamber E but connects by the passage I-K, K, compression pipes leading from
both ends of the cylinder, L an air cock: M a spiral spring, and N N receiving
chambers.
Mode of operation: the pipes K being connected to the compression chamber,
one by valve 1 and the other by valve 2, by being screwed into the bosses P, by
opening the air cock L free vent is given to the cylinder from both ends at the
same time and which empties the chambers N, pipes K, and the chamber H-By
closing the cock L and screwing down the regulating plug G until the spring M
exerts a pressure on the valve seat D¹ of, say, a trifle over the initial steam pressure,
the chamber H, pipes K and chambers N will fill with water to the points
marked a a-
-By the movement of the engine piston any excess of water now
passes alternately by valves 1 and 2, the one forming a check or closing the other
by its superior injection-The water after entering the compression chamber H now
raises the regulating piston valve B and escapes at the exhaust port F which may
be connected with the cock L and both discharges carried to some convenient
point The moment the excess is passed, the piston B closes by means of the
power exerted by the spring M, and thereby retaining at all times the set pressure
in the chamber H-In the event of over cushioning of steam, through imperfect
action or slip of the main engine valve or by overstroke caused by taking up lost
motion & such excess will pass out of the cylinder and displace a portion of the
water in the globes N or N, which I construct of a size of about the cube contents
of the cylinder clearance-Such displacement will then discharge a larger quantity
of water by the port F; but the steam almost instantly returns to the cylinder-.
This action of the apparatus not only prevents straining, but economizes the steam,
and may be known to occur by the cessation of the pulsations of the rod D for a
few strokes of the engine, or until the water once more fills to the points a a.

page_text: The apparatus may be placed away from the Engine, against the wall of the
Engine house, or on one side of the ship or in any convenient place provided the
valve seat I) is always a few inches below the points a as shown.
As a modification of my Invention especially for use on large engines the piston B
may be operated by means of a lever and weight, instead of the spring M and
separate cheek valves used on the pipes K, as a substitute for the valves 1 and 2.
Figures 3 to 5 represent the form of apparatus in which a double relief valve is
employed Figure 3 being an elevation partly in section, showing the improved
double relief valve applied to a horizontal engine cylinder-Figure 4 a view
(enlarged) of the valve apparatus detached and Figure 5 a detail view illustrating
a modification.
Like letters indicate like parts in these three figures.
The discharge or valve chamber A is made in one hollow casting-top, bottom
sides and ends The relief valves are placed one at each end and as they are alike,
one description will suffice for both The bushing B which forms the valve seat is
screwed into the bottom of the discharge or valve chamber-The pipe C. leading
from the end of the cylinder is connected with the bushing through the T piece D.
and a short coupling pipe-A pet cock E is screwed into the lower opening of the
T piece-The valve has a stem F above, and a stem G below the valve disk H-
The lower stein is a common fly stem so that the water may pass and is guided by the
bushing B-The upper stem F is a cylindrical rod and fits closely but not tightly in
the contracted sleeve or neck I at the lower end of the spring chamber K-This
chamber is screwed into a hole in the top of the discharge chamber A, the valve
being placed in position when the spring chamber K is inserted-The spring L, in
the form of a spiral compression spring is confined in the chamber K between the
disk M on top of the upper valve stem F and the plug N screwed into the upper
end of the chamber-The plug has a central perforation through which passes the
rod P, screwed at the lower end into the disk M-The plug N is also provided with a
stuffing box Q-The outlet-pipe R is screwed into the bottom of the discharge
chamber and may be extended so as to lead the water from said chamber to any
convenient point-As shown in Figure 5 the rod P is dispensed with and the
perforation in the plug N is closed by a small screw plug S. It is preferred to
make the valve and its stems of harder metal than the bushing which forms the
seat therefor, namely the valve of phosphor bronze and the seat of brass The
bushing B when screwed home projects into the discharge chamber so as to give
metal that may be gradually worn away or ground off in use-A bushing will there-
fore last a long time.
The apparatus is placed at any convenient point with the valves upright. as shown
in the drawings-It is so connected with the steam cylinder T that the valve
disk H is below the bottom of said cylinder-A few inches below will suffice: but a
greater distance is not injurious.
The operation will be readily understood. On closing the petcocks E the pipes C.
T piece D, and bushing B fill with water-After that all excess is ejected into the
discharge chamber A, each valve being lifted as occasion may require, against
the pressure of spring L. The discharged water is led off by the outlet pipe R.
The pressure of the spring L is adjusted by the screw plug N so that it is greater
than the pressure of the live steam, but is light enough to yield when over com-
pression occurs in the end of the cylinder-Preferably it is so adjusted that the
valve lifts slightly at the end of each stroke, but closes again the instant the piston
leaves the cylinder head.
This can be ascertained by observing the movements of the rods P, or if it be
preferred to use the form of plug shown in Figure 5 by removing the plug S,
inserting a straight wire through the hole in plug A and allowing it to rest
upon the disk M and observing the movements of the wire-The wire should of
course be long enough to project.
A similar construction of valve and valve seat could be used in an apparatus
having a single valve, one such apparatus to be used at each end of the cylinder.

page_text: The benefits to be derived by the use of this auxiliary exhaust are many. The
efficiency of an engine, whether high, or low pressure, or condensing, is increased
and an
evenness of motion produced throughout the entire mechanism―The
removal of strains and jars saves considerable repairs and insures against delays
and the possibility of personal scalding, or worse, in the event of a cylinder
head being blown off-It insures an economical use of steam and is therefore a
fuel saver, and while providing a constant relief for the water, its construction is
such that neither live nor exhaust steam can escape.
Having thus fully described my said Invention what I claim is
1st The combination with a relief valve and compression pipes leading thereto,
of check valves for preventing the fluid being forced back through one pipe by the
pressure in another substantially as described.
2nd The combination with an engine cylinder and a compression pipe leading
therefrom of a relief valve connected with said pipe and an air cock also connected
with said pipe and arranged below the relief valve so as to draw off the fluid between
it and the cylinder said cock and the seat of said relief valve being arranged below
the point where the pipe opens into the cylinder substantially as described.
:
3rd The combination with an engine cylinder of a compression pipe leading there-
from, and a spring actuated relief valve connected with said pipe, the latter
descending below its junction with the cylinder, and both it and the chamber on the
cylinder side of the valve being constructed and arranged to maintain constantly
a body of water between the cylinder and the relief. valve substantially as
described..
4th In steam engines the compression or relief pipes K, cylinder A and the
relief valve B operating, in the manner shown, in combination with the receiving
chambers N, all operated for the purposes and in the manner substantially
specified.
5th The relief valve B, chamber E with its exhaust F, the screw plug G,
spring M, compression chamber H, and pipes K. K. in combination with the check
valves 1 and 2 all arranged and operated in the manner and for the purposes
substantially as specified.
6th The air cock L in combination with the chamber H, the relief valve B,
exhaust F compression pipes K and cylinder A for the purposes and substantially
in the manner specified.
7th The combination with an engine cylinder of a relief valve apparatus and the
compression pipes connecting a common chamber in said apparatus with both ends
of said cylinder, said apparatus and said pipes being constructed and arranged to
maintain constantly a body of water between the said apparatus and both ends of
the cylinder substantially as described.
8th A double relief valve apparatus comprising two relief valves combined with a
common discharge or valve chamber in combination with an engine cylinder and
two pipes leading from the cylinder to said chamber the pipes or passages between
said cylinder and said valves being closed and arranged below the opening into the
cylinder, so as to maintain a body of water therein and each valve controlling the
communication of one of said pipes with the discharge chamber substantially as
described.
9th The combination of the two relief valves with common discharge chamber,
constructed with top, bottom, sides and ends in one piece or casting, the spring
chambers of the valves being made separately from the discharge chamber and
screwed into separate holes in the walls thereof substantially as described.
10th In combination with a relief valve, the valve seat formed of a renewable
bushing of softer metal than the said disk, and the compression-pipe connected with
said bushing so that the latter forms a continuation thereof substantially as
described.
11th The combination with the valve disk and its upper stem in the form of a
rod or cylinder, of the close-fitting sleeve or neck surrounding said stem, the disk

page_text: above said sleeve or neck, and the relief spring also above said sleeve or neck, and
pressing against said last named disk to hold the valve to its seat, said spring and
the disk against which it acts being larger in diameter than said stem substantially
as described.
12th The combination with the discharge or valve chamber of the valve having
an upper stem, the relief spring, the disk against which said spring acts, and the
spring-chamber projecting into said discharge or valve chamber and being contracted
at its inner end to form a sleeve or neck surrounding said stem, said disk and
spring being larger in diameter than the said stem and being arranged in the
enlarged part of the valve chamber above said sleeve or neck substantially as
described.
13th The double relief apparatus comprising in combination, the common
discharge chamber, the renewable bushings constituting the valve seats, the spring
chambers contracted to form a sleeve or neck at the bottom and screwed into the
said discharge chamber on the opposite side from said bushings, the valves having
upper stems guided by said sleeves or necks and the relief springs, substantially as
described.
14th The valve having an upper sliding stem the spring chamber contracted at
the bottom to form a neck or sleeve in which said stem slides, the disk, the relief
spring arranged in the enlarged part of said chamber above said neck or sleeve, and
the perforated screw-plug closing the upper end of said spring chamber substantially
as described.
15th The valve composed of a valve disk of hard metal with one or more guide-
steuns in combination with the renewable bushing of softer metal constituting the
valve seat, and the compression pipe connected with said bushing, so that the latter
forms a continuation thereof substantially as described.
16th The combination, with the valve and the discharge or valve chamber, of the
screw-bushing constituting the valve seat, and projecting inside the discharge
chamber on one side of said chamber and the spring chamber screwed into the
opposite side thereof, said spring chamber, containing the relief spring and forming
a guide for the said valve substantially as described.
17th The combination with the engine cylinder the pipes connected with
opposite ends of the cylinder and the two relief valves, one for each pipe of the
separate petcocks, one for each pipe, arranged below the corresponding relief valve
substantially as described.
18th The combination of the valve having an upper stem, the spring-chamber
contracted at the bottom to form a guide for said stem, the disk in the enlarged part
of said spring chamber, the relief spring, the screw plug in the end of the spring
chamber, and the indicating rod sliding in said plug and fixed at its lower end in
said disk, substantially as described.
19th The combination of the valve, the spring chamber contracted at the bottom
to form a guide for a stem on said valve, the relief spring, the disk above the valve,
the screw plug in the outer end of the spring chamber, the stuffing-box in the said
screw plug, and the indicating rod playing through said stuffing box and fixed at
its lower or inner end in said disk substantially as described.
20th The combination with the discharge chamber, of the valve of hard metal,
the chamber forming a guide to said valve and screwed into one side of said
chamber, and the screw bushing of soft metal screwed into the opposite side of said
discharge chamber, and projecting into the latter and forming a seat to said valve,
substantially as described.