IMPROVEMENTS IN STEAM TRAPS
Year: 1884

page_text: COMPLETE SPECIFICATION.
I WILLIAM PHILLIPS THOMPSON, Fel. Inst. P.A., of the Liverpool and London
Agency for Foreign Patent Solicitors 6 Lord Street Liverpool in the County of
Lancaster, Civil Engineer, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN STEAM TRAPS" and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:
This Invention has relation to improvements in that class of steam traps
ordinarily known as "Expansion Traps "wherein the outlet is governed or regulated
by the expansion and contraction of an inner tube in excess of an outer tubo
caused by the difference in the temperature of the two tubes, the operation being
such as to permit water to escape but to check the escapo of steam.
The objects of the present Invention are to so construct the seat for the lower
end of the inner expansion tube that it may be easily and quickly adjusted or
fitted so as to insure perfect contact with the lower end of said tube or the fitting
thereon be permitted to expand under the pressure produced upon it without
danger of destroying its usefulness and be reversible so as to afford ready means of
supplying a new seat when required-to provide the lower end of the expansion
tube with a bearing-piece so constructed as to afford always a free and clear escapo
passage between it and the scat therefor, which passage will not be liable to
become clogged by foreign matter-to provide a simple efficient and durable form
of packing for the inner expansion tube-to provide a strainer upon the inlet end
of the expansion tube to prevent admission of foreign matters thereto and to
provide a simple and efficient means of clearing out or blowing out the separating
chamber. To accomplish all of this the improvements involve certain novel and
useful peculiarities of construction, relative arrangements or combinations of parts
and principles of operation all of which will be herein first fully described and
then pointed out in the claims.
In the accompanying Drawing forming part of this Specification,:
Fig. 1 is a vertical section and elevation of an expansion trap constructed and
arranged for operation in accordance with the Invention and embodying the
principles thereof, a portion being broken out to facilitate illustration.
Fig. 2 is an elevation on a smaller scale than Fig. 1 showing in addition to
Fig. 1 exterior ribs which may be applied if desired.
Fig. 3 represents a plan and section of one of the removable soft-metal discs.

page_text: Fig. 4an elevation and plan of the reversible carrier employed for morning the
Beats.
Fig. 5 a plan of the top, side elevation, and plan of the bottom of the
removable fitting or plug applied upon the lower end of the expansion tube.
Fig. 6 is a sectional elevation of the lower end of the expansion tube showing
the fitting screwed into the interior theroof.
Fig. 7 is a similar view wherein the screw-threads are omitted and the
fitting inserted without them being held in place by friction against the inner
surface and
Fig. 8 is a sectional clovation of the improved form of packing-gasket applied
between the inner and outer tubes.
A is the outside tube or body of the trap which may or may not be provided
with ribs B, as shown in Fig. 2. Upon the upper part of the tube is secured the
separating chamber C having the inlet c, and connecting with chamber C is the
inner expansion-tube D which extends down to the outlet section of the apparatus.
E is the outlet from the trap.
In the lower end of tube A is secured the block or holder F which has a cavity
for the reception of the scat discs G G and their carrier H. Through this block
the adjusting screw I projects, the same being provided with any suitable jam nut
as K, by which it is held in place after adjustment, and with a projecting cap ·L
to prevent accidental or unauthorized manipulation.
The carrier H is made of brass or any composition sufficiently hard, its central
cylindrical part being fitted accurately to the cavity in the block F and the two
projections 66 at top and bottom being turned to receive the seat discs. The scat
discs G G are centrally perforated to fit upon the. projection bb and they are
made slightly conical and somewhat less in diameter than the cavity in the block
or holder F.
These discs are of soft metal so that in being pressed upon by the lower end of
the expansion tube all the wear will come upon them and so that they will insure
a perfectly tight-joint.
After long use the discs will be compressed and their upper faces expanded or upset,
and by making these discs conical, as shown, room for this expansion is provided
between the discs and the wall of the cavity in the block F, so that the discs
cannot become wedged and are always free to be adjusted by use of tho adjusting
screw.
The upper end of the block Fis turned off accurately at right angles to its axis
and being of harder material than the discs will serve as a guide for filing them
down to level their faces so that they may be accurately fitted when required
after wear. Should one disc become unserviceable for any reason, the carrier has
only to be inverted in its soat in the holder to bring a new disc into position for
immediate operation and this can be very quickly accomplished by simply removing
the holder F and turning the carrier therein.
In this class of traps it is found that minute particles of scale and other foreign
matter sometimes become lodged between the seat-disc and the end of the expansion
tube, preventing accurate contact all around and interfering with the uniform
passage or liquid causing it to cut channels in the seat and other wise to prevent
the desirable sensitive and accurate operations of the trap.
To obviate all this the bearing end of the expansion tube is provided with
two independent bearing surfaces for contact with the seat disc and these are
made as follows:
In one form, Figs. 1 and 5, a plug T is screwed into the lower end of the
expansion tube. This plug is centrally perforated to permit the outward flow of
liquid and is formed at bottom with two concentric rings or ledges de leaving au
annular space between them. For convenience of inserting this plug the upper
part of the central perforation f is made square or angular for the reception of
any suitable implement by which it may be easily seated.

page_text: In the second form represented in Fig. 6 the plug T enters further into the
lower interiorally threaded end of the expansion tube, the other ring for bearing
upon the seat disc being formed by the expansion tube itself, and in the third
form the screw-thread is omitted and the plug simply driven to place. In each of
these forms the principle is the same.
The interior ring is preferably made thicker than the outer ring so as to nearly
equalize the area of bearing surface of the two upon the seat disc. Any scales or
particles which find their way to the scat are caught and retained by the inner
ring and by that ring may be compressed into the soft metal of the seat disc and
the fluid or liquid passing this inner ring and interrupted by such particles will
before its final escape from beneath the expansion tube expand so as to completely
fill the opening between the outer ledge and the disc and then escape in a free and
uninterrupted current all around. The outer ledge will always make a tight seat
upon the disc whether the inner ledge be obstructed or not and thus the steam will
be effectually trapped. The plug is made of hard metal and in the second and
third forms it is preferably a little harder than the expansion tube so that the
inner ledge or ring will be not only thicker but harder than the other one.
Around
the lower part of the expansion tube is the packing gasket N screwed into a
threaded ledge on the interior of tube A fitting the expansion tube closely and
operating to divide the interior of the outer tube into two chambers and to prevent
communication between the two.
This gasket as shown is for a portion of its length reamed out leaving the upper
and lower parts thereof connected by a narrow neck, and around the bottom of the
gasket is a considerable space or channel between it and the tube A, the purposo
of all of which is to permit the gasket to expand and contract with the expansion
tube without interfering with the longitudinal expansion and contraction of said
tube and always preserving a tight joint therewith. This construction is simple
cheap and efficient besides which it affords an accurate guide or steadyment for
the expansion tube insuring its proper contact with the seat disc.
The expansion tube is extended up into the separating chamber and provided
with a series of perforations a a above the bottom of said chamber, the purpose of
which is to form a strainer to prevent foreign matters from passing down
the expansion tube. The top of the tube is closed in any suitable manner as by
the plug g.
To clear the separating chamber of any accumulations therein I connect it with
the drain or outlet pipe N through the medium of a tube O on which is any
suitable valve as P. Steam being admitted to the trap upon opening valve P, a
current is produced through the expansion chamber which will effectually clear it
out after which the valve should be closed.
The connecting tube may be omitted however and the matter simply blown out
through an opening in the wall of the chamber which opening may be stopped by
any ordinary plug. When steam and water enter the separating chamber the
water finds its way down through the expansion tube and out at the outlet, and
when the water has passed out the steam enters which being more highly heated
causes the further expansion of the expansion tube to such a degree as to force
its lower end or the fitting thereon into steam tight contact with the seat disc and
when this contact occurs the steam will be effectually trapped. I find it
advantageous to supply the upper end of the tube A with a globular enlargement
or chamber as R which assists to render greater the difference in elongation of
the inner and outer tubes under the effect of heat, but this globe may be omitted
if desired.
Having now particularly described and ascertained the nature of the said
Invention, as communicated to me, and in what manner the same is to be
performed, I declare that what I claim is:
1st. In a steam trap of the character herein set forth, the seat disc carrier
provided with the two discs and made reversible in its holder, substantially as and
for the purposes set forth,
P

page_text: 2nd. The herein described scat disc mado conical and arranged in the holder
substantially as explained, so as to leave a space between the two for the purposes
and objects set forth.
3rd. In a steam trap of the character herein set forth, the dischargo end of
the expansion tube having the two independent ledges or rings with the annular
space between them for contact with the seat disc, substantially as shown and
described.
4th. In a steam trap the packing gaskot combined with the inner and outer
tubes, the same being reamed out at top having a narrow connecting neck between
its upper and lower parts, and arranged to expand and contract with the inner
tube and to prevent communication between the two compartments into which it
divides the outer tubo, substantially as shown and described.
5th. In a steam trap the outer tube provided with the expanding chamber, the
expansion tube extending up into said separating chamber and being perforated as
explained, the packing gasket surrounding the lower end of the expansion tubes and
preventing communication between the compartments above and below it, and a
valve or cut-off operated by the expansion tubo, all combined and arranged
substantially as shown and described.
6th. In a steam trap of the character here set forth, the combination of the
expansion tube, outer tube, packing gasket separating chamber, cut off operated
by the expansion tube, and the blow off pipe provided with a valve and
connecting the discharge pipe and separating chamber, substantially as shown and
described.