Improvements in Steam Traps.
Year: 1893

page_text: Date of Application, 16th Sept., 1893
Complete Specification Left, 18th Dec., 1893-Accepted, 17th Feb., 1894
Improvements in Steam Traps.
I, CHARLES FRASER, of 51 Thomson Street, Govan, Lanarkshire, Engineer, do
hereby declare the nature of my invention to be as follows:-
This invention has reference to a new or improved construction or arrangement
and combination of the parts of steam traps for trapping and discharging the
condensed steam or water from steam pipes, or from other apparatus or places where
such may collect under steam pressure, and refers more particularly to that class of
steam traps which are situated at a lower level than the pipe or other part to be
drained of condensed water, and which it is believed will by these improvements
be rendered more efficient in action than those hitherto in use and occupy
comparatively small space.
Under one arrangement the improved trap is formed with an outer casing or
shell of brass, cast iron, or other suitable metal preferably cylindrical with a domed
bottom aud top, and which may have a screwed on top or cover, but preferably
formed in two main top and bottom parts screwed together, or in some cases secured
together by flanges and screwed bolts. A branch leads the steam and water of
condensation into either the top or bottom part of this shell, and the water is
discharged by a lateral branch pipe leading from a short branch projecting down-
ward from the domed bottom. At the lower part of the domed bottom is formed
or inserted a valve seat on which rests a hollow valve with conoidal lower part and
fitted on the upper part of a hollow stem or spindle fitted with feathers and which
communicates with the interior of the bollow valve through an internally contracted
neck. To the lower end of this hollow spindle is screwed or secured a piston
working within the branch projecting from the bottom of the shell which branch is
bored to fit it, and has an internal collar for it to bear up against; the piston
having an opening through its centre so that water may pass through the stem
from the hollow valve to its under side to raise it. After insertion of the piston
the branch is closed by a screwed cap or cover, but a spiral spring may in some
cases be inserted between the cover and the bottom of the piston to assist the
pressure of steam or water in raising it. Within the upper part of the shell a float
formed of solid porcelain or earthenware but preferably, of hydraulic compressed
tile is carried on a vertical spindle. The upper end of this spindle rests in a guide
or bearing formed in the top of the shell and allowing of a slight vertical movement
and the lower end, which is formed conical enters through an opening a little wider
than itself in the top of the hollow valve in which it is retained by a collar on it,
but which allows of some little play, and forms a valve to close the opening from
the hollow valve to the hollow spindle and piston. The float is partly supported
by a spiral spring below it and kept in place by a flange or equivalent on bottom
of float and it may be one around the valve seat at bottom of the shell. Or in some
cases instead of using a supporting spring the spindle of the float may be carried
up through a stuffing box on the top of trap and the float be partially supported by
an adjustable weighted lever connected to the top of spindle.
The action is as follows, when the water accumulates within the shell it raises
the float which by rising lifts the lower point of its spindle and opens com-
munication through the hollow valve and spindle to the space below the piston,
which being of greater surface than the valve is forced up, and lifts the valve,
thereby opening communication from the bottom of the shell to the discharge
branch, and when the water is discharged the falling of the float shuts off again the

page_text: communication through the hollow valve and its stem and the discharge valve will
be closed.
Dated the 1ith Santonsbau 1802
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.
1, CHARLES FRASER of 51 Thomson Street, Govan, Lanarkshire, Engineer, do
hereby declare the nature of my invention, and in what manner the same is to be
performed, to be particularly described in and by the following statement in writing
reference being had to the accompanying drawings and to the letters and figures
marked thereon :-
My invention has reference to a new or improved construction or arrangement and
combination of the parts of steam traps for trapping and discharging the condensed
steam or water from steam pipes, or from other apparatus or places where such may
collect under steam pressure, and refers more particularly to that class of steam
traps which are situated at a lower level than the pipe or other part to be drained
of condensed water, and which it is believed will by these improvements he rendered
more efficient in action than those hitherto in use and occupy comparatively small
space.
And in order that my said invention may be properly understood I have hereunto
appended an explanatory sheet of drawings in which
Figure 1 is an elevation, principally in section, of one arrangement of my
improved steam trap, and Figure 2 is a plan of same partly in section.
Under this arrangement the improved trap is formed with an outer casing or
shell A of brass, cast iron or other suitable metal preferably cylindrical with a
domed bottom and top and which may have a screwed on top or cover, but
preferably formed in two main top and bottom parts A', A², screwed together as
shown, or in some cases secured together by flanges and screwed bolts. The
projection a on the top part A' being formed of a hexagonal or other augled shape
for screwing it on with any suitable implement. A brauch A leads the steam and
water of condensation into the lower part A of this shell A, or it might be led into
the upper part A, and discharged through a lateral branch pipe A from a short
branch or passage A leading downwards from the domed bottom. At the lower
part of the domed bottom is formed or inserted a valve seat a on which rests a
hollow valve B with conoidal lower part and fitted on the upper end of a hollow
stem or spindle C which might be fitted with feathers and which communicates
with the interior of the hollow valve B through an internally contracted neck c.
To the lower end of this hollow spindle C is screwed or secured by a nut da
piston D working within the branch A or in a small chamber A formed in the
same line, as shown in the drawings, projecting from the bottom A² of the shell A,
and which is bored to fit it and has an internal collar a² for the piston D to bear up
against, the piston D having an opening d¹ through its centre so that water may
pass through the stem C from the hollow valve B to its under side to raise it..
After insertion of the piston the branch is closed by a screwed cap or cover a³ but
a spiral spring not shown in the drawings may in some cases be inserted between
the cover a and the bottom of the piston D to assist the pressure of steam or water
in raising it. Within the upper part of the shell A à float E formed of solid
porcelain or carthenware but preferably of hydraulic compressed tile is carried on
à vertical spindle E' on which it is secured by screwed nuts. The upper end E
of this spindle E' rests in a guide or bearing e formed in the top A¹ of the shell A
and allowing of a slight vertical movement and the lower end E3 which is formed
conical enters through an opening B a little wider than itself in the top of the

page_text: hollow valve B in which it is retained by a collar e' on it, but which allows of some
little play and its conical end E3 forms a valve to close the opening from the hollow
valve B to the hollow spindle C and piston D. The float. E is partly supported by
a spiral spring F below it and kept in place by a flange or projection E or
equivalent on the bottom of the float E and it may be a flange at around the valve
seat at bottom of the shell A. A grating or perforated plate G is inserted as shown
into the inlet branch A³ to intercept mud or solid particles in the water and which
has a bolted on cover G and a screwed plug G for clearing purposes below, but
this I do not claim as any part of my invention, and a small screwed plug with
turning handle as shown at H may be fitted to any convenient part of the discharge
branches A and A' to enable the action of the trap to be tested.
Instead of using the spring as shown at F Figures 1 and 2, the float E may in
some cases be suspended by a spring as shown at F Figure 3 attached to the lower
part of an adjustable screwed spindle H passing through the top a' of the casing A
and adjusted to the desired height by turning either by a key on a square head H¹
or by other means.
The action is as follows:-When the water accumulates within the shell A it
raises the float E which by rising lifts the lower point E³ of its spindle and opens
communication through the hollow valve and spindle C to the space below the
piston D which being of greater surface than the valve B is forced up and lifts
the valve B, thereby opening communication from the bottom of the shell to the
discharge branch A' by the passage A' and when the water is discharged the falling
of the float E shuts off again the communication through the hollow valve B and
its stem C and the discharge valve B will be closed as the pressure ceases to act on
the bottom of the piston D.
Having now particularly described and ascertained the nature of tny said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is
First. The construction or combination and arrangement of the parts of steam
traps all substantially as herein described in reference to and shown in the
accompanying drawings.
Second. In steam traps, the combination of a solid float having its supporting
spindle made to form a valve with a hollow valve, a hollow stem and a raising
piston, all substantially as and for the purposes herein described in reference to and
shown in the accompanying drawings.
Third. In steam traps, the combination of a hollow valve, hollow stem, and a
raising piston, all substantially as and for the purposes herein described in reference
to and shown in the accompanying drawings.
Dated 16th December 1893.
W. R. M. THOMSON & CO.,
96, Buchanan Street, Glasgow, Agents.