Improvements in Steam Traps.
Year: 1893

page_text: Date of Application, 30th Aug., 1893
Complete Specification Left, 21st Mar., 1894-Accepted, 28th Apr, 1894
PROVISIONAL SPECIFICATION.
Improvements in Steam Traps.
1, JOHN HENRY DEWHURST, of Attercliffe Road, Sheffield, in the County of
York, Mechanical Engineer, do hereby declare the nature of my said invention to
be as follows:-
The object of my invention is to so construct a steam trap that it shall be rapid
in its action, simple and inexpensive in design.
I construct the case or box by preference circular in form, comparatively narrow
in width and provided with a lid, an inlet and an outlet, the inlet being placed
tangentially at the upper circumference of the box (which stands on edge) and the
outlet is placed likewise tangentially at the lower circumference of the box.
The inlet orifice I provide with an adjustable valve seat, which can be screwed
or otherwise set inwards or outwards as may be required, such seat in some cases I
likewise employ as part of a union provided with suitable fittings for connecting to
the inlet pipe.
On this valve seat which faces inwards into the trap I provide a suitable valve
with wings, fitting within the seat, to guide it when being opened or closed. To
the end of this valve I attach a bent or coiled rod which may be made in various
sections solid, or hollow, or in the form of a tube, and constructed of some metal or
metallic alloy or other substance highly sensitive to heat. This valve rod I fit
closely, nearly the whole way round the inner circumference of the box, its total
length being equal to about the full inner circumference, though in some cases it
may be made longer or shorter according to circumstances.
This valve rod as already stated is secured at one end to the valve, and at the
other end, by a set screw and stop or their equivalents, to the inner case of the
box. I also provide guides for this valve rod where necessary.
When the valve and rod are in place, the seat is adjusted so that the valve closes
lightly on to it when steam of a sufficiently high temperature is present in the box
to cause the valve rod to expand to the required degree.
The action of my improved trap is as follows, when the seat has been adjusted
and the connections made, on steam being admitted into the steam service pipes,
whatever water is present in the pipes is forced by the pressure of the steam
through the valve into the box of the trap, through which it continues to flow and
escape by the outlet until all the water in the pipe has been ejected, steam then
commences to flow and pass through the trap. As soon as the steam enters the
trap the valve rod is expanded by the heat and closes the valve which remains
closed until the action of the external atmosphere on the case of the trap causes
the temperature to fall, in consequence of which the valve rod cools and contracts
when the valve is again opened and whatever water may have accumulated in the
pipe is allowed to escape. The presence of water in the pipe will likewise prevent
the steam from coming in contact with the valve until all the water has passed
through, during which the water passing through the trap exercises a cooling
influence upon the rod of the valve which is in consequence kept open until all the
water has escaped and steam re-enters the trap when the valve is again closed by
the action already described and so on.
As a modification of the arrangement herein described, in some cases I place the
trap upside down, reversing the inlet and outlet, in this position the inlet is always
open to the steam which condenses within the box, and as soon as the water rises a
sufficient height to cool the valve rod, the valve rod contracts, the valve opens and

page_text: the water present escapes, as soon as steam again enters the box the valve rod
expands and the valve closes and so on.
By the last named arrangement the steam trap forms a reservoir for any sudden
flow of water which may be caused by priming or from other sources.
In either of the above modes of construction the case of the steam trap is
provided with suitable feet to stand upon, or brackets, or fixings by which it may
be attached to a wall of a building or other suitable place.
Dated this 29th day of August 1893.
R. HEBER RADFORD,
Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Steam Traps.
I, JOHN HENRY DEWHURST, of Attercliffe Road, Sheffield, in the County of
York, Mechanical Engineer, do hereby declare the nature of my said invention
and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement :-
The object of my invention is to so construct a steam trap that it shall be rapid
in its action, simple and inexpensive in design.
I construct the case or box by preference circular in form, comparatively narrow
in width and provided with a lid, an inlet and an outlet, the inlet being placed
tangentially at the upper circumference of the box (which stands on edge) and the
outlet is placed likewise tangentially at the lower circumference of the box.
The inlet orifice I provide with an adjustable valve seat, which can be screwed
or otherwise set inwards or outwards as may be required, such seat in some cases I
likewise employ as part of an union provided with suitable fittings for connecting
to the inlet pipe.
On this valve seat which faces inwards into the trap I provide a suitable valve
with wings, fitting within the seat, to guide it when being opened or closed in some
cases I employ a ball or other form of valve. To the end of this valve I attach a bent
or coiled rod which may be made in various sections solid, or hollow, or in the form
of a tube, and constructed of some metal or metallic alloy or other substance highly
sensitive to heat. This valve rod I fit closely, nearly the whole way round the
inner circumference of the box, its total length being equal to about the full inner
circumference, though in some cases it may be made longer or shorter according
to circumstances.
This valve rod as already stated is secured at one end to the valve, and at the
other end, by a set screw and stop or their equivalents to the inner case of the box.
I also provide guides for this valve rod where necessary.
When the valve and rod are in place, the seat is adjusted so that the valve closes
tightly on to it when steam of a sufficiently high temperature is present in the box
to cause the valve rod to expand to the required degree.
The action of my improved trap is as follows, when the seat has been adjusted
and the connections made, on steam being admitted into the steam service pipes,
whatever water is present in the pipes is forced by the pressure of the steam through
the valve into the box of the trap, through which it continues to flow and escape by
the outlet until all the water in the pipe has been ejected, steam then commences
to flow and pass through the trap. As soon as the steam enters the trap the valve
rod is expanded by the heat and closes the valve which remains closed until the
action of the external atmosphere on the case of the trap causes the temperature to
fall, in consequence of which the valve rod cools and contracts when the valve is again
opened and whatever water may have accumulated in the pipe is allowed to escape.
The presence of water in the pipe will likewise prevent the steam from coming in
contact with the valve until all the water has passed through, during which the

page_text: 1, 1, are the guides provided for the valve rod and
m, the feet for the case or box to rest upon.
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. In a steam trap the combination of parts and appliances comprising the uarrow
circular formed case or box provided with a lid, an inlet and outlet, the inlet orifice
being provided with an adjustable valve seat and valve, such valve being attached
to a bent or coiled rod constructed of some metal or metallic alloy highly sensitive
to heat and secured within the case and provided with or without guides as may be
required in the manner and for the purposes substantially as herein described and
illustrated.
Dated this 4th day of Novomhor 1902
R. HEBER RADFORD,
Agent for the Applicant.