US2746685A - Thermostatic valve for steam trap - Google Patents

Description

May 22, 1956 E. L. MYERS THERMosTATIc VALVE FOR STEAM TRAP Filed Feb. 2, 1953 United States Patent() 2,746,685 p 'HIERMOSTATIC VALVE FOR STEAM TRAP Errol L. Myers, Detroit, Mich., assignor to Howard O. Trerice, Detroit, Mich.

Application February 2, 1953, Serial No. 334,461 3 Claims. (Cl. 236-53) My invention relates-to steam traps and more particularly to a valve structure therefor comprising a thermal responsive valve applicable to an upright bucket type trap, and actuable to automatically operate the trap mechanism when air pockets happen to collect in the trap interior to such an extent as to prevent normal trap operation.

While applicants assignees have for several years installed .valves of this` type in bucket type traps, the valve assemblies have been such as to make it practically impossible to. make repairs or replace such valves in the field. These valves have in generalv been permanently mounted internally of the bucket, and it has been necessary to return the entire bucket to the factory when replacement of the thermostat valve element becomes necessary.

It is an object of my present invention to facilitate assembly of these thermally responsive valves and to facilitate servicing of same by constructing the assembly with a replaceable thermostat valve element which can be quickly detachably assembled with an adapter mounted on an external surface of the bucket.

A further object of the invention is to provide for maximum life with a minimum of service expense by constructing an improved valve assembly incorporating an adapter operable in conjunction with a snap action thermostat valve to provide a free unrestricted opening whereby a maximum of rapid flow of the trapped water is had to minimize collection and build up sludge formations about the opening and the valve seat, that will in time interfere with the normal eicient operation of the trap.

For a more detailed understanding of my invention,

reference may be had to the accompanying drawing illustrating a preferred embodiment of the invention, in which like characters refer to like parts throughout the several views, and in which: h Fig. l is a vertical sectional View of a steam trap hav- 111g an upright bucket and carrying a thermally responsive snap action valve assembly constructed in accordance with the present invention.

Fig. 2 is a fragmentary side elevational view of the bucket showing said thermally responsive valve in elevation.

Fig. 3 is a detailed sectional view of the valve assembly taken on the line 3-3 of Fig. 2 and showing the valve closed, and

Fig. 4 is a detailed sectional view of the valve assembly similar to Fig. 3, but showing the valve open.

The steam trap A, with which my invention is applied, comprises a steam trap body consisting of a casting providing a chamber or sump 11 in which a condensed moisture from the steam line will collect. This condensate will buoyantly support the upright bucket 12, said bucket carrying the valve 13 which is guided in suitable guides 14 and seated to close the outlet' 15. This outlet 15 is carried by the head casting 16 secured to the body 10 and this head casting provides a closure 2,746,685 Patented May 22, 1956 for the open end casting 10 and is provided with an outlet 17. Steam is admitted to the trap through the inlet 18.

In the normal operation of the trap, the water collected in the chamber or sump 11 will rise and eventually overflow into the bucket 12, causing the bucket to sink, opening outlet 15 and the water is discharged from the bucket and when the amount Withdrawn is suflicient to buoyantly support the bucket, it closes off outlet port or opening 15.

At times an air pocket may form in the trap and when this occurs, it does not allow for the entrance of steam` into the trap and the confined air pocket becomes great enough to block the rise of water in the trap, preventing this water from overflowing the rim of the bucket, thus preventing normal trap operation.

A snap valve 20 is embodied in the wall of the bucket near the bottom, and when air pocket is trapped in the trap as described above, no moisture from the steam is added thus resulting in the temperature of the water dropping. When the temperature of the water in sump 11 is lowered to a predetermined low degree, the thermal responsive valve 20 is actuated to open the bucket interior to the water in sump 11, the introduction of such Water overcoming the buoyancy of the bucket and opening the outlet 15.

The thermal valve structure 2t! is mounted externally of the bucket.. This valve structure assembly comprises an adapter 21, preferably circular in plan and the adapter and bucket are provided with a number of holes, the adapter being located by these holes and secured to the external surface of the wall of the bucket by hollow tubular rivets 22, said hollow rivets providing a plurality of open passages 23 connecting the bucket interior with the space or chamber 24 defined in said adapter within the annular peripheral flanged lip 25 of the adapter. The adapter is constructed with a central hub 26 having a tapped hole 27 at the center, the lip being concentric with this hub.-

A shouldered screw 2S is threaded into the tapped hole 27 and clamps the bi-metal thermostat disc 29 to the at outer face of the hub, the peripheral portion of this disc overlying the lip 2S or" the adapter.

Under normal operation of the steam trap, the temperature of the water in the sump il is such as to maintain the disc valve 29 seated in the lip .'25 closing of the interior of the bucket from the sump l1, as illustrated by Fig. 3, but as the temperature of the water in the sump falls to a predetermined degree, the bi-metal disc 29 will snap to an open position as illustrated in Fig. 4. The Water then suddenly and rapidly rushes past the lip 2S into space 24 through passage 23 into the bucket. After the discharge of the bucket and the entrapped air pocket, the trap again operates normally and the disc 29 is subjected to hot steam and water and it snaps shut. Then snap action and sudden opening and closing of the opening about the periphery of the adapter provides for a rapid flow of water and minimizes the build up or accumulation of sludge deposits about the periphery of the lip or the valve seat.

The bi-metal disc 29 is readily removed to replace a new one when necessary, this being necessary from an orifice, said valve structure comprising an adapter provided with a perforated plate portion and an annular flange encircling said plate portion to form an outwardly opening recess, a plurality of hollow rivets in said plate perforations for securing said adapter to the wall of said steam trap bucket and acting to conduct water i'low, and a snap acting thermostatic disc carried by said adapter and located to overlay the annular flange to close ot communication between the outside and inside of said bucket, said snap disc distortable in response to temperature changes to snap open and provide a free unrestricted opening about the entire periphery of said adapter.

2. A thermostatic snap valve structure assembled with a steam trap bucket for controlling water iloW through an orice, said valve structure comprising an adapter provided with a perforated plate portion and an annular flange encircling said plate portion to form an outwardly opening recess, said bucket having openings registering with the perforations in said adapter plate portion, a plurality of hollow rivets threaded in said plate perforations and openings in said bucket for securing said adapter to the wall of said steam trap bucket and acting to conduct water flow, a snap acting thermostatic disc concentrically disposed relative to said adapter, and means disposed substantially centrally of said disc and adapter to secure said disc to the adapter, said thermostatic disc located to overlay the annular ange to close oft communication between the outside and inside of said bucket, said snap disc distortable in response to temperature changes to snap open and provide a free unrestricted opening about the entire periphery of said adapter.

3. A thermostatic snap valve structure assembled with a steam trap bucket for controlling water ow through an orice, said valve structure comprising an adapter provided with a perforated plate portion and an annular ilange encircling said plate portion to form an outwardly opening recess, said bucket having openings registering with the perforations in said adapter plate portion, a plurality of hollow rivets threaded in said plate perforations and openings in said bucket for securing said adapter to the Wall of said steam trap bucket and acting to conduct water ow, a snap acting thermostatic disc concentrically disposed relative to said adapter, said adapter having a centrally disposed post and said perforations arranged around said post, a snap acting thermostatic disc concentrically disposed relative to said adapter, and means disposed centrally of said disc to secure same to the adapter post, said thermostatic disc located to overlay the annular flange and said recess to close off communication between the outside and inside of said bucket, said snap disc distortable in response to temperature changes to snap open and provide a free unrestricted opening about the entire periphery of said adapter.

References Cited in the le of this patent UNITED STATES PATENTS 1,420,045 Lippert I une 20, 1922 1,812,722 Spencer June 30, 1931 2,232,583 Zies Feb. 18, 1941 2,509,482 Crise May 30, 1950

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