US1656373A - Thermostatic trap - Google Patents

Description

,Jan. 17, 1928. 1,656,373

J. L., FITTS THERMOSTATIC TRAP FiledvJune 13, 1925 2 Sheets-Sheet l [We/112v". James 05m F/f/s.

Jan. 17, 1928.

J. L. FITTS THERMOSTATIC TRA 2 Sheets-Sheet 2 Filed June 13, 1925 M/forn ey.

Patented Jan. 17, 1923.

JAMES LOGAN FITTS, 0F MERCHANTVILLE,

NEW JERSEY, ASSIGNOB '10 WARREN WEBSTER & COMPANY, A CORPORATION OF NEW JERSEY.

THERMOSTATIC TRAP.

Application filed June 13, 1925. Serial No. 88,858.

Thermostatic traps for steam heating and other purposes and employed for permitting the escape of water of condensation and air while restricting or preventing theescape of steam have heretofore been constructed with a thermostatically operated valve piece, the expansible member of which comprises a bellows-like structure Whose lower part is provided with a valve piece and its upper part attached to the cap or bonnet of the surrounding body whereby the thermostat-1c member is rigidly secured to the casing. as a whole; but it frequently happens that where the bellows is subjected to high temperature and pressure, severe strains occur from water hammering which cause it to fail to function properly, and in which case, it is necessary to replace the expansible member wlth accuracy and facility, without removing the valve body from its connection with the steam and waste pipes.

The object of my invention is to provide a simple and efficient means for supportlng the thermostatic member within the valve body and relatively to the valve seat therein, so as to be accurately positioned to respond to predetermined temperature and pressure conditions, either or both, and which supporting means for the thermostatic member is readily clamped, directly or indirectly, lIl position within the body or cas ing by the cap or bonnet, providing a yreldmgc'ontaet therewith for positively holding the thermostatic member upon the body in accurate operative relation irrespective of any var1ations in the positioning of the cap or bonnet, relatively to the body, the construction being such that the removal of the cap or bonnet permits release and read access to and removal of the thermostatic member and its attached support for repairs or replacement,

and when in clamped position, the support for the thermostatic member always insures a definite predetermined relative positlon between the support and the valve seat.

My invention consists of a body or casinghaving a valve seat and a definitely positioned shoulder or ledge in respect to said seat, combined with a sheet metal disk structure resting upon the said shoulder or ledge and carrying a thermostatic member with its valve piece in accurate position with res ect to the valve seat of the body, and in w ich further, the plate is clamped upon the shoulder or ledge by means of a cap or bonnet attached to the casing or body, an interposed yielding structure being positioned between the cap or bonnet and the disk whereby said disk is clamped definitely upon the supporting shoulder or ledge (and the valve piece is accurately positioned with respect to the valve seat), irrespective of any small variation or irregularity of the clamping action of the cap or bonnet with the casing or body.

My invention also consists of a thermostatically operated trap characterized by raving the supported end of the thermostatic member provided with a suspension plate having spring portions by which, through the agency of the cap or bonnet,-the plate is clamped or held in definite correlation with respect to the body structure and valve seat thereof, while being wholly enclosed within the casing.

My improvements also include the suspension means for the thermostatic member, when made of disk-like form resting upon a shoulder or ledge within the body to definitely limit the distance of suspension in respect to the valve seat, and provided with spring portions bent to one side of the plate of the disk-like suspension means, said spring portions clamped by the cap or bonnet against movement away from the valve seat but, at the same time, permitting the upper part of the thermostatic member and disk-like suspension means secured thereto slightly moving in a direction away from the valve seat in case of heavy water hammering.

My invention also comprehends details of construction which, together withthe features above stated, are fully described here inafter and more specifically defined in the claims.

Referring to the drawings: Fig. 1 is a vertical section of a thermostatic trap and embodying my improvements; Fig. 2 is a lan view of the suspension disk thereof; ig. 3 is a perspective view of the suspension disk; Fig. 4 is a verticalsection of the upper part of a thermostatic trap showing a modification of my invention; Fig. 5 1s a plan view of the sheet metal suspension plate before being bent into final shape for use in the structure of Fig. 4; Fig. 6 is a perspective view of the suspension plate shown in Fig. 4; Fig. 7 is a cross section of a high pressure thermostatic trap embodying my lmprovements; and Fig. 8 is a lan view of the thermostatic member and suspension ate.

p Referring more specifically to Fig. 1, 2 is the body casing of the trap and is provided with an inlet port 3 open into the side of the body and an outlet port 4 having a perforated valve seat 5 arranged at the bottom of the valve body. 6 represents the cap or bonnet and is detachably secured to the upper open end of the body 2 through the medium of an inwardly directed circular flange 13 screw threaded at 11 into connection with the upper end of the body. The depth of the circular flange 13 is less than the depth between the open end of the body and the internal shouldered portion '12 thereof so that there is provided an annular groove or channel at 14 between said shouldered portion 12 and the inner end of the flange 13.

The thermostatic member 3 is preferably of bellows constructioiuand is fitted at the bottom with a conical valve piece 7 and its upper end is closed by the usual plate 9 having a projecting screw threaded stud 10. 15 is a suspension plate which is provided with a central aperture 16 through which the screw threaded stud 10 extends, and said suspension plate is tightly clamped upon the top plate of the thermostatic member 8 by means of a nut 18. In practice, the distance between the suspension plate 15 and the end ofthe valve piece 7 is definitely and accurately provided by screwing the conical valve piece 7 into the lower end of the thermostatic member 8 and securing it in such adjustment by a transverse pin 7.

The body 2 is counter-bored to provide the annular groove 14 and shoulder 12 in an accurate manner so that the distance between the said shoulder and the surface of the valve seat 5 is exactly provided; and. furthermore, the relation between the conical valve piece 7 and the diameter of the aperture in the valve seat 5 is properly proportioned so as to make the valve accurately responsive when the thermostatic member and its plate is ositioned within the body and definitely c amped upon the annular shoulder 12 thereof.

The plate 15 has its perimeter made with radial slots 17 by which tongues 17 are provided, the same being bent upwardly and radially to form a plurality of spring tongues above the normal plane of the plate and which are pressed downward toward the late by the flange 13 of the cap or bonnet.

n this manner, the accuracy of the thermostatic member within the bodv 2 is assured and the plate is positively held down in contact with the shoulder by the spring pressure of the tongues 17 when forced downward by the action of the cap flange 13. It will be understood that should, for any reason, it

. operative be necessary to replace the thermostatic member, it only becomes necessary to remove the cap or bonnet 6, lift out the defective thermostatic member, replace it by a new member in which the plate of the new member rests upon the shoulder, and thereafter clamping the plate in position by the cap or bonnet.

Where the pressure and temperature are high and especially where the valve is large, there is always more or less liability of the seating of the valve piece to cause a water hammering effect in the action of the surging water within the body 2, and its effect upon the thermostatic member. This water hammering is due to the seating of the valve piece 7 upon its seat and its sudden rise therefrom under the pressure difl'erential between the contents of the body and the return or waste pipe, and should this water hammering be such as to tend to abnormally raise the thermostatic member and its associated plate 15 to a minute extent, the spring tongues 17 would permit sutlicient yielding to remove an excessive strain upon the thermostatic member itself. This capacity will increase the life of the thermostatic member by reducing some of the strains which otherwise would come upon the metal of the bellows. It will be understood that the pressure above the plate and within the cap or bonnet is substantially the same as the chamber of the trap in which the thermostatic member is located, because the bent portions to form the tongues 17 provide spaces to opposite sides of the plate 15 through which the steam or gaseous medium may freelv circulate. In this manner,-there is no differential permitted between the space above and below the suspension plate and consequently the thermostatic member and its suspension plate 15 normally retains the position shown in which the shoulder definitely insures the operating valve piece for accurate control of the escape brought in the valve seat. The suspension plate is shown in Figs. 2 and 3 in addition to the illustration in Fig. 1, and may be made of any metal which is highly resistant to corrosion and which will retain its resiliency at the high temperatures of the steam. I have found that phosphor bronze is satisfactory, also monel metal, cupro nickel alloy, and stainless steel may likewise be employed, and the latter which is non-corrosive will give the longest life to the disk.

Referring to Figs. 4. 5 and 6, the general construction and operation of the parts are substantially the same as in Fig. 1, but the suspension plate is modified in construction. In this case, the disk 15 is provided, as before, with the central aperture 16 and the perimeter with a plurality of radial tongues 17. but these are bent upward and inward as shown in Figs. 4 and 6 to provide the latter is slit radially as at 17 Ill] spring parts which fit into the annular groove 14. The plate 15 rests upon the annular shoulder 12 of the body and the spring tongues are pressed downward by the annular flange 13 of the cap or bonnet 6 to retain the suspension plate in position. To enable these spring tongue parts being kept substantially within the diameter of tlli e disl)(,

1g. 5 but to a less extent than in the cases of F ig. 2. Since the suspension plate in this case is of a diameter substantially equal to the diameter of the flange 12 and counter-bore, holes 15 are provided through it to permit of the passage of steam or air to equalize the pressure above and below the thermostatic member.

Referring now to the construction shown in Figs. 7 and 8, which is more especially useful in high pressure traps, the body portion of the trap is in general similar to the construction shown in Figs. 1 and 4, with the exception that the upper open part of the body is not screw threaded to receive the cap or bonnet. In this case, the counter bore 14" is quite shallow but provides the annular shoulder 12 as before. The sus pension plate 15 is circular and snugly fits the counter-bore so as to rest upon the shout dei- 12. The depth of the counterbore 14 is substantially the thickness of the plate 15. Resting upon the upper annular surface of the body above the counter-bore 14 and partly upon the suspension plate 15 is an annular gasket or packing ring 17 d which is preferably of copper and asbestos, as coinmonly-employed for packed joints, though I do not restrict'myself as to the particular composition of the gasket. For roperly positioning the gasket, it is manifhst that the upper surface of the body may be provided with a counter-bore of a maximum diameter equal to the outer diameter of the gasket. The cap 6 fits over the body and has its underside formed with an annular rim which directly rests upon the gasket or packing 17 and said cap is clamped down in position upon the gasket by the cap screws 11. A. 'oint of this kind between the cap and the ody is very strong and well suited to high pressure steam traps.

he suspension plate 15 is provided with a central hole 16 through which'the stud 10 of the thermostatic member 8 passes, and said member is secured to the plate and slightly spaced from it by an annular washer 18 arranged between the shoulder of the top plate 9 of the thermostatic member and the underside of the suspension plate 15 and by a nut 18 screwed upon the stud and clamping the plate down upon thespacing washer 18*. The suspension plate 15 is' provided with apertures 15 through the same whereby the space within the cap and the space within the body are continuously tion of this application in communication so that the pressure above and below the plate is equalized. The thermostatic member 8 may be of any suitable construction but preferably of the character illustrated in Letters Patent N 0. 1,235,673, granted to me on August 7, 1917, wherein there is a bellows construction corresponding to 8 and having at its lower part a conical valve piece 7.

It will be seen that in the structure shown in Fig. 7, the distance between the under surface of the suspension plate 15 and the top surface of the valve seat 5 is fixed, and that as the thermostatic element is carried by the .plate the position of the valve in respect to the orifice in the valve seat will always be the same when the parts are assembled with the underside of the plate resting u on the shouldered portion 12.

With t e construction shown in Fig. 7, it will be seen that replacements of the interior parts of the trap may very easily be accomplished by removing the cap screws 11, lifting off the cap 6", removing the ring gasket 17 and lifting out the interior thermostatic member with its attached valve piece and suspension plate and replacing the thermostatic member and plate with a new'part and thereafter replacing the gasket and the cap and bolting the latter tightly'in place upon the body andgasket, and the trap will be found in proper adjustment in respect to the valve piece 7 and the vali e seat 5. If the valve seat is worn, it is also readily replaceable by unscrewing the old seat and inserting a new one. These replacements may be made without removing the trap from its connection with the piping or other apparatus with which it is em loyed.

lVhile the traps embo ying the construcmay be utilized for ordinary radiator purposes in which from one to ten pounds steam pressure may be used (for which the ty e shown in Figs. 1 and 4 is well suited), tie articular benefit of the improvement is bad when the parts are used for high pressure such as from ten to one hundred pounds which, being large, involves the attachment of the cap or bonnet by cap screws such as in Fig. 7, because in this case, the employment of a asket between the body and the cap and t e irregularity in clamping the cap in position would interfere with the accurate positioning of the thermostatic member relatively to the valve seat if it were not for the fact that the shouldered portion 12 of the counter-bore and the suspension plate of thethermostatic member absolutely insure the accuracy of .the thermostatic member within the body.

It will now be apparent that I have devised a novel and useful construction which embodies the features of advantage enumerated as desirable, and while I have in the present instance shown and described the preferred embodiment thereof which has 7 been found in practice to give satisfactory and reliable results, it is to be understood that I do not restrict myself to the details, as the same are susceptible of modification in various particulars without departing from the spirit or scope of the invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. In a thermostatic trap, the combination with a body having inlet and outlet ports the latter provided with a valve seat at the lower part of the body and the body further rovided with an annular supporting shou der or ledge lying in a plane above both the inlet and outlet orts, a thermostatic member arranged wit 1in the body at a level above the inlet port and having at its bottom a valve piece, a suspension plate having a diameter greater than the thermostatic member and seating upon the central part of which the thermostatic the shoulder or ledge and to chamber between the cap or bonnet and the plate.

2. The invention according to claim 1, wherein further, the suspension plate is formed with a pluralit of integra spring portions immediately a jacent to and spaced about its perimeter and so positioned that they may be put under compression by the cap or bonnet to hold the plate firmly upon the annular shoulder or ledge of the body.

3. The invention according to claim 1, wherein further, the suspension plate is provided with spring portions about its perimcter whose ends extend upwardly from the plane of the suspension plate and so positioned that they may be put under compression by the cap or bonnet to hold the plate firmly upon the annular shoulder or ledge on the body, said spring portions being confined to and integral with the plate'near its perimeter.

4. The invention according to claim 1, wherein the thermostatic member comprises a bellows having a stud at its upper end extending through and clamped to the suspension plate and provided at its lower end with an adjustable valve piece whereby the distance from the valve plece to the suspension plate may be definitely adjusted.

In testimony of which invention, I hereunto .set my hand.

JAMES L. FITTS.

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