US2820594A - Thermally controlled air vent valve for steam heating system - Google Patents

Description

THERMALLY coN'TRoLLE'D AIR VENT VALVE FOR STEAM HEATING SYSTEM Filed Nov. 10, 1955 Jan. 21, 1958 T M s @5505; 2,820,594

WAS/212675804 United Sttes Patent THERMALLY CONTROLLED AIR VENT VALVE FOR STEAM HEATING SYSTEM Thomas M. S. Gibson, Milwaukee, Wis., assignor to The Dole Valve Company, Chicago, Ill., a corporation of Illinois Application November 10, 1955, Serial No. 546,138

3 Claims. (Cl. 236-62) The present invention relates to vent valves, and more particularly to a type of vent valve normally used in conjunction with the radiators or unit heaters of steam heating systems for venting entrapped air from the steam line.

Proper operation and efficiency of steam heating systems make it desirable that entrapped air be vented from the system. Moreover, particularly in the instance of steam heating systems with which the valve of the present invention is particularly adapted and useful, desired qualities of effectiveness and capacity make desirable an operation at a relatively high temperature and pressure.

Thus it is an object of this invention to provide an efiective air vent valve operative at fairly high conditions of temperature and pressure.

Another object is to provide an air vent valve having a positive shut-off, which even at such high operating conditions will vent only the air from the system, and block escape of the fluid heating media.

Another object is to provide an air vent which will be effective to block escape of both steam and condensate or other liquid which may be present.

A further object of the present invention is to provide a new and improved valve means for venting air from a steam heating system, which is responsive to a selected temperature to close the vent passage to prevent escape of operating steam, but which is adapted to block escape of condensed steam at all temperatures, even below that temperature at which it is temperature-responsive with respect to the operating steam.

A still further object is to provide such an air vent valve useful with steam heating systems, which is simple and economical in construction, manufacture, and assembly, which will be effective to accomplish its intended functions, and which will give reliable and trouble-free performance over a prolonged period of time.

These and other objects, features, and advantages of the present invention will be readily apparent from the following description of a certain preferred embodiment thereof, taken in conjunction with the accompanying drawing, in which:

I Figure 1 is an elevational view of a vent valve according to the present invention.

Figure 2 is an enlarged longitudinal cross-sectional view somewhat diagrammatic, of the valve shown in Figure 1; and

" Figure 3 is a transverse cross-section, taken generally along the line III-III of Figure 2.

As shown in the drawing, the valve comprises a shell or body member 10. The shell desirably comprises three parts, including a base 12 provided with a nipple 14 for attaching the device to an associated fitting in the associated radiator or other heating line, a cylinder or barrel 16 providing a working chamber, and an outlet fitting through which the entrapped air is to be vented.

A hexagonal tool-engaging portion 18 of the base 12 permits the device to be connected into the heating system, the nipple 14 providing both external screw threads 20 and internal screw threads 22 alternatively usable to eflect such connection.

Patented Jan. 21, 1958 The venting outlet 15 is shown as having threads 23 threaded into the barrel 16, and is drilled to provide passageways 24 and 24 to provide venting communication between the interior of barrel 16 and the atmosphere. Passageway 24 is adapted to serve as the bore of a needle valve 26. A plunger 28 of the needle valve 26 is normally carried at a lower or retracted position, providing an open condition of the valve 26 and venting means 24-24' whereby entrapped air may be vented. The plunger 28 is adapted by means now to be described to be moved upwardly to close the valve 26 and the vent passage in response to the presence of either steam or fluid in the valve.

For effecting a closure of the valve 26 in response to the presence of liquid in the body 10, float means such as a bulb 30 is provided. The float 30 is desirably secured as by soldering 32 to the plunger 28 of the needle valve 26 and is adapted to be lifted by liquid which may be present in barrel 16, thereby raising valve plunger 28 and thus closing the valve 26. The lower end of the float 30 carries a guiding plunger or rod 34 desirably secured as by soldering 35 to the float bulb 30. Rod 34 is guided, desirably by structure associated with a temperatureresponsive device 36 yet to be described, to guide the float 30 and the valve plunger 28 which it carries, in a controlled reciprocating movement providing the desired axial alignment of the valve-plunger 28 in the needle valve 26.

The temperature-responsive device 36 is shown as a thermal element of a so-called power or wax type. It has a power member or piston 40 extensible from a cylinder 42 at a selected temperature. A casing 44 of the device 36 extends outwardly from the cylinder 42 and contains a thermally expansible material, which may be a wax alone or a wax and a powdered heat conducting material and binder, such as is shown and described in Patent No. 2,259,846 which issued to Sergius Vernet on October 21, 1941. The thermal element 36 is shown as being of the same general type as shown and described in the Vernet Patent No. 2,368,181, dated January 30, 1945. Such an element is commonly known as a Vernet or Vernay thermal element. In such an element, the thermally expansible material carried within the casing 44 expands as it reaches its fusion point and acts against a membrane or deformable member (not shown) to extend the piston 40 from the cylinder 42 at its temperature of actuation.

The thermal element 36 is shown as carried within the base-portion 18 of the shell body 10 by supporting means such as a spider 50, the arms 50a of which extend generally radially to engage and be supported on an upwardly facing shoulder on the inside of the inner wall of the base 18. The spider 50 is desirably formed as a sheet-metal stamping, the central portion of which extends upwardly from the arms 50a to provide a sleeve 50b within which is disposed a restoring or return spring 52 for the piston 40 of the thermal element 36. The spring 52 is bottomed against an abutment means shown as annular flange or web 50c pressed inwardly from the upper end of the spider sleeve 50b. 'The central portion of the annular web 50c of the spider 50 is formed to provide the axially-extending guide-collar 50d adapted to guide the plunger 34 of the float-bulb 30.

The return spring 52, just described as being bottomed against the spider web 500, is disposed within the spider 50b generally axially. In thrust engagement with spring 52 are fingers 54a of a thrust-transmitting means such as the saddle 54. Inwardly of the fingers 54a, the saddle 54 extends upwardly and thence inwardly to a central portion 54b which is thrus'tingly engaged by the piston 40 of the thermal device 36 and a'pertured to receive an extension or nib 40a of piston 40' which serves to center the saddle.

Itwill be apparent that upon extension of the piston 40 of the thermaldevice 36 in response to the temperature existing at casing 44 at a level sufiicient to actuate the thermal device 36, the piston bears against.

the float plunger 34 (through saddle portion 54b, in the specific form illustrated) to lift valve-plunger 28 to. close the vent-valve 26. Moreover, extension of thermal element piston 40 lifts the saddle .54 to cause its fingers 54a to compress the return springr52 against the spider web 50c against which it is bottomedto load'the spring 52. So long as the temperature remains at or above:

the rated temperature of the thermal element 36, the vent valve remains closed, and the return spring 52 remains loaded. When the temperature drops to a point below the rated temperature of the thermal element 36, the return spring 52 acts through the saddle fingers 54a and the saddle 54 to urge and help move the piston 40 downwardly to return it to its normal retracted position in which the vent valve 26 is open.

Since thermal elements of the Vernet typev shown are comparatively powerful, over-travel means indicated generally by the reference numeral 60 are provided. Such over-travel means 60 shown comprise an overtravel spring 62 axially disposed about the spider sleeve 50b and adapted to bear downwardly against the arms 50a ofthe spider 50. As shown, it is through this overtravel spring 62, rather than directly by either the shell or the supporting spider 50, that the thermal element 36 is carried. Thus thermal element 36 is carried by a carrier member 66, fingers 66a of which are formed inwardly to provide an abutment. engageable by the top of the over-travel spring 62. This structure permitsthe thermal device 36 to back off or drop, to permit continued extension of piston. 40 relative to cylinder 42 of the thermal element 36 after the seating of the plunger 28 in the vent-valve 26. The over-travel arrangement permits abnormal excessive temperatures without damage to the thermal device 36, for when the vent-valve is fully closed, further extension of the thermal device is accommodated as the thermal device 36 simply backs ofi. The compression of the over-travel spring 62 incident to such backing-otf of thermal device 36 of course loads that spring 62 to cause it tourge carrier 66 and the thermal device 36 back to normal position.

It will. thus be seenfrom the foregoing description of my inventionv according to apreferredembodiment, considered in conjunction with the accompanying drawing, that the present invention provides. a; new and im- I proved vent valve having the desired advantages and characteristics, and accomplishing. its. intended. objects including those hereinbefore pointed out and otherspwhich are inherent in, the invention as described.

It will. beunderstood that modifications and variations' of the present invention maybe effected without departing from the scope of the. novel, concepts thereof.

1 claim. as my invention:

1. In an air. vent; valve. for steam radiators and. the

like, a, generally vertically extending body havinga,

float chamber therein, an inlet into said body from the bottom thereof for attachment .to a .steam radiator, an axially extending outlet leading through thetop of said chamber in axial, alignment with said inlet, a spider mounted in said chamber adjacent the bottom thereof and having an axially extending guide in axial alignment with said inlet and said outlet, a float within said chamber between saidspiderand said outlet andhaving a. guide rod depending therefrom and slidably guided insaidguide and having a. plunger'extending upwardly therefrom in axial alignment withv saidjguide. roda and having, a valve on: the. end thereof engageable-withjsaid outletipassageway to block the passage, of steam therethrough, said float engaging said valve with said outlet passageway upon the accumulation of water Withinsaid 4 chamber, and means for closing said valve independently of said float to block the passage of steam through said outlet comprising a thermal element yieldably carried in said spider for relative movement with respect thereto and having a power member extensible upon predetermined increases in temperature in axial alignment with said 1 guide; rod .for'moving said guide rod to close said valve upon the heating of said thermaljelement by steam-enteringsaid :inlet t 2. Inan-air vent valve forsteam'ra'diators and the like, a body having a float chamber therein, an inlet-into said body from the bottom thereof for attachment to asteam radiator, an axially extending outleLleading from the top of said chamber in axial" alignment with said inlet, a spider mounted in said chamber adjacent the bottom thereof and; having an .axiallyextendingguide, in axial alignment with said.inlet-,.and; .aid outlet, av float within;

said e etw en saidpider and; said outlet. and having a guidezrod, depending. therefrom and slidably guided in said guide, ,saidfloat, having, a plunger extending upwardly therefrom :in axial alignmentwith saidguide rod and, having; a; valve; on the upper end thereof. en:

- ing said float, toengage said valye withsaid outletpassage.

way upon the heating of sai hermal element by, steam. entering said-in et,- andta pr ng. for. s d p s seated within said;spider;and havingoperative connection with said piston.

3. In an air ventvalyepfor steam, radiators. and the like, a body having a,;float:chamber;therein; an inlet. into said body fromthebottom thereofpforv attachmeutno a steam i r,. n; xiallx xten ng. u rle d ne hrou the top of said chamber; in axialalignment with saidin let, a spidermounted,in; said; chamber adjacenmhebot: tom thereof andh aving an; axially extending guide in axial alignment with saidinletand. said outlet, afloat,

in said chamber between said guideand: said. outlet and having a guide rod depending; th'erefrom slidably guided in said guide and having a plunger extending upwardly therefrom in axialalignment with said, guide rod and; having a valve on theuppenend thereof engageable with said outlet, said float closing-said valve toprevent water from passing through. said outlet uponthe; accumulation of water within saidchamber, ,and means, closing said,v

valve upon. the passing of steam within said chamber through said inlet, comprising a thermal element'havinga casing containing a fusible thermally expansible material and a power member extensible from, said casing upon fusion of the fusible expansible-rnaterial contained within said casing, a saddle slidably guided in said spider and having supporting engagement with said casing of said thermal element, a spring encircling said -spider-and seated betweensaidspider and saddle and yielding upon overtravel of said piston, said saddle supporting saidcasing with saidpower member in axial; alignmentwith said guide rod, and a return spring seated within, said spider and having operative connection with said piston for. re-

turning said piston upon predetermined reductions in a temperature.

References Cited in the Y file or this patent UNITED STATES PATENTS 227,361 J ones et al. May 11,1880 1,646,686 Crosby- Oct. 25, 1927 1,984,402 Donnelly 'Dec. 18, 1 934 2,396,138 Vernet Mar. 5 19.46, 2,731,239 Andersen Jan. 17, 1956'

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