US2013369A - Boiler and like safety valve - Google Patents

Description

Sept. 3, 1935- M. w. T. TURNER BOILER AND LIKE SAFETY VALVE Filed Dec. 4, 1951 4 Sheets-Sheet l lNv vToR BY; 47W

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BOILER AND LIKE SAFETY VALVE Filed Dec. 4, 1951 4 Sheets-Sheet 2' 777- 24 U. 944mm BOILER AND LIKE SAFETY VALVE Filed Dec. 4, 1931 4 Sheets-Sheet 3 Fig.7

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V BOILER AI ID LIKE SAFETY VALVE Filed Dec. 4, 1951 4 Shets- Sheet 4 ,4". m arner Patented Sept. 3, 1935 UNITED STATES PATENT OFFICE BOILER AND LIKE SAFETY VALVE Maurice Walton Tudsbery Turner, Glasgow, Scotland Application December 4, 1931, Serial No. 579,077 In Great Britain December 13, 1930 8 Claims.

5 valve are practically uninterfered with by the flow of the steam through the valve.

The invention consists in applying the valve lifting pressure in opposition to the Valve loading means at a part not in the path by which fluid passes through the valve when it opens.

The invention further consists in applying the valve lifting pressure in opposition to the valve loading means at a part not in the path by which fiuid passes through the valve when it opens, the escaping fluid travelling into and out of the valve substantially at right angles to the valve axis so that the velocity of the escaping fiuid has substantially no influence upon the valve movements.

The invention also comprises various features concerned with the valve and with loading means adapted to afford substantially constant load conditions which will be hereinafter described and defined in the claims.

In the accompanying drawings:

Figure 1 is a sectional elevation illustrating one form of valve device according to the invention.

Figure 2 is a sectional plan View taken on the line XX of Figure 1.

Figures 3 and 4 are respectively an enlarged detail side elevation and plan of loading links shown in the upper part of Figure 1, and their knife edge seating.

Figure 5 is a sectional elevation of a modified form of valve member.

Figure 6 is a side elevation partly in section of a valve device according to a modified form of escape chamber, and

Figure 7 is a side elevation partly in section of a valve device according to a modification (suitable for higher capacity work) in which a pair of valves communicate with a single inlet branch from the boiler or pressure vessel.

' Figure 8 is a sectional plan view through the ports of Figure 6 by which steam issues into the atmosphere, but showing a modified construction. Figure 9 shows a modified arrangement of the means for loading the valve spindle from the thrust links hereinafter described.

In carrying the invention into effect according to one convenient mode by way of example, an inlet housing I is provided and shaped internally after the manner shown in Figure 1, the housing being secured to the boiler or other steam vessel in the usual way. Upon the housing I is a casing 2 for the escape or outlet side of the valve 3.

Within the inlet passage 4 of the housing I, an inverted conical member or deflector 5 is positioned by screw threaded means, such as indicated at 6, (or it may be cast integral with the housing) and is adapted to guide the steam in a path which approaches the valve 3 horizontally or at right angles to the valve axis.

The valve 3 fits into hollow, cylindrical seatlngs at l and 8, the upper end of the part 1 providing a seating surface at I to be hereinafter referred to, and the lower end of the part B being closed by the member 5 which has, however, a tube or pipe 9 thereon which extends to a part of the steam space of the boiler or vessel where relatively quiescent conditions exist. The said pipe 9 allows such quiescent steam to apply with lifting pressure upon the lower surface 9 of the valve 3 as described hereinafter.

If desired, the valve seating ring 8 and deflector 5 may be formed in one piece supported in the casing or housing I.

The valve 3 is of hollow cylindrical form to fit into the cylindrical seating portions 1 and 8, and has a closed lower end at 9 exposed to the steam pressure acting through the tube 9. Two circumferential rows l0 and H of apertures are formed in the valve wall, one row (I I) being below the upper edge 8 of the ring 8 when the valve is closed, and the other row (I0) being below the upper edge of the valve seating surface 1 when the valve 3 is closed. As the ,valve opens and closes, the fiow area through the ports [0, II, is substantially the same.

The valve has a top closure l2 to which the loading pressure is applied.

In the form shown in the drawings, the closure l2 has a screw threaded extension to which a sleeve member I3 is secured, the closure forming a seating for the end of the valve spindle or loading stem M. A projecting collar or shoulder upon the top closure 12 is adapted to engage upon the seating surface I when the valve is in the closed position, so as to limit the downward movement of the valve.

The valve 3 may be loaded by dead load, lever and weight, by a spring or springs.

The valve loading stem M has a shoulder I l thereon upon which rests a collar which may be loaded at its upper side by a coil spring of adjustable compression in any ordinary manner, but it is preferred to provide a spring loading device employing thrust links adapted to aiford substantially constant loading, as hereinafter described.

In order to ensure that the steam issuing past tit the seating edge 1 when the valve is open, passes out horizontally or at right angles to the valve axis, an escaping chamber 55 is loosely mounted upon the closure 82, the chamber being held by a locating pin it with its outlet aperture 55 opposite the outlet 2? of the casing 2; An alternative form, of escape chamber l5 and casing 2 is shown in Figure 6 wherein a pair of diametric apertures, I5 are provided opposite the outlets 2 whereby any tendency to the production of a side thrust upon the valve 3 by the chamber [5 is eliminated. Such outlets 2 may lead to a common outlet 2 as shown in Figure 8.

Due to the fact that the pressure acting upon the underside of the end 3 of the valve 3 is obtained from a relatively quiescent part of the steam space, and that the flow of escaping steam into and out of the valve cylinder 3 is substantially at right angles to the axis of the valve so:

that any forces set up by such escaping steam tend substantially to neutralize one'another '(in Sdfar as 'the'openingfor closing of the valve is concerned); Iam enabled to secure a correct opening of the valve in accordance with the boiler orlike pressure undisturbed by forces due to the velocity or rush of the steam escaping from the valve. The upper end of'the valve is equal in-=area to the part 3 and is exposed to atmospheric pressure in the loading chamber which is unaffected by the escaping steam;

*The casing 2 is conveniently formed with a dished top portion 2 for supporting a loading chamber-comprising a disc 5?,annular wall is and columns E3 (see Figure 2'). The dished top 2? holdsa collar 83 for guiding the sleeve or extension -t3 of the part- !2. The disc H has a central" bush 13 enclosing an adjustable screw threaded sleeve-23 having a hexagon end 2% or other manipulating hold. The valve stem M hasa lever 2i (which passes through a cotter way in the spindle end) loosely pinned therein. In -use, thelever 2i bears upon the top edge of the sleeve 23 as a fulcrum.

- The valve stem i i and valve member 3 are loaded in opposition to the pressure exerted uponthe valve end 3 by the steam through the pipe 9-, by compression springs 22, 23 mounted upon an equalizing cross head 24 by the aid of coaxial spindles 25 which pass through the cross head andthrough spring caps 26 and which are secured to a yoke 21. r 7

- 7 :The cross head His pivoted to a central member 28 slotted to accommodate the spindle i4 and having an adjustment screw bolt 29 carrying an abutment piece 33, A similar abutment piece 31 is 'secured in the yoke 27. I

An upper and lower pair of oblique thrust links 32, 33 are disposed parallelogram fashionas seen in Figure 1', each having knife edge ends preferably slotted and inwardly hooked as illustrated .on theleft hand of Figure 4 and elsewhere. The outer knife edged ends of the links are seated in inclined grooves upon each side of a projection prevent rotation, the bushing l 9 is provided with slots engaged by projecting ribs upon the block 36. Each block 35, 33 has a pair of undercut lugs 32'! for seating the knife edged inner ends of the thrust links. in. position against accidental dislodgment by drical thrust bearing.

The ends of the link are retained eating members 33 secured by screws 39 and having on each side arcuate recesses 40 in which the hooked ends of the links engage (see Figure 4). The outer ends of the links are similarly retained in their operative position by members 38, the member associated with the screw bolt 29 being apertured to pass the latter (see Figure 2.)

From the above description, it will be appreoiated that the loading system isconstructed as an independent unit and as such can be detached at will for purposes of replacement and repair. In order to modify the performance of the valveas desired, the adjustment screw 23 is turned. Adjustment of the blowing off pressure is effected by the screw 29. By screwing this into the member 28, the latter is drawn towards the right hand abutment 30 taking with it the cross head 23 (see Figure 2). This movement increases the compression of the springs 22, 23 and the load upon the valve 3, and is transmitted via'the spindles 25 to the yoke-'2'! and thereby to the left hand abutment block. 3 In the modificationshown in Figure '7, a pair of oppositely disposed valve-members 3 and lower seatings 8 are provided with their axes at right angles to the steam admissionpipe S. The deflector member 5 in this case-is of duplex form and is adapted to provide passages for escaping steam parallel to the axis of the pipe 9 and-at right angles to the axes of the valves. The sin gle outlets 2 rise vertically andafford a direct flow without bends. V valve devices are not shown in Figure 7-asthese are similar to the construction already described with reference to Figure 1. a

It will be apparent that instead of a pair of valves as indicated in Figure 7, three valves may be employed with their axes arranged at 120 intervals.

As an alternative to forming the valve-member 3 (or members '3), Figures 1 and 7-, of sleeve form, it may be of piston like form having its control elements mounted upon a spindle 41 (Figure 5). The lower end of the spindle carries a cup member with the ports I i therein, whilst the upper ports i3 (seen in Figure 1) may be omitted, the upper active portion of the valve beingconstituted by the annular shouldered end member it, like that shown in Figure 1. The endmember i2, Figure 5, has a similar extension sleeve 13 to that referred to in connection with Fig-,

ure 1.

In the arrangement of the thrust links 32,- 33 shown in Figure 9, cylindrical thrust bearings are interposed between the abutment blocks 35, 36 and the shoulder l l 'on the spindle M ami the screw threaded sleeve 20 respectively. Each thrust bearing comprises two parts and with contacting surfaces which are partsof cylinders. By this means I ensure'that binding upon the spindle It will not result from any slight throwing over of the parts 35 and 36 by the links 33 and 32 respectively. The abutment blocks may be formed integrally with one 'part of each cylin- Whilst I have described. my invention with reference to its application to a boiler or vessel containing steam, it will of course be understood that it can be applied as a safety valve on vessels containing other fluids, such as gas, air, water and the like. V

I may vary the details of my improved valve and seat to suit any particular requirements; 7

What I claim is:-- V

1. The combination in ahigh liftsafety valve,

The outer portions of the' of a valve comprising a hollow cylinder with inlet and outlet ports therein, a part closing one end of said hollow cylinder (and not in the path by which fluid passes through the valve) to which valve-lifting fluid pressure is applied, and a 010- sure for the other end of said hollow cylinder; a cylindrical valve seating surrounding said hollow cylinder and controlling the flow of fluid to and from said inlet and outlet ports respectively, loading means adapted to hold said valve on said cylindrical valve seating, and a housing with inlet and outlet branches and having a channel for delivering fluid to said part of the cylinder and a separate channel for delivering fluid radially to said inlet ports when said valve opens, the fluid flowing radially into and out of said valve and having its direction of flow altered by the two ends of the cylinder so that the flow has substantially no influence upon the valve movements.

2. The combination with a high lift safety valve as claimed in claim #1, said last mentioned channel comprising a pipe in said inlet branch to admit fluid to said part of the cylinder and a deflector surrounding said pipe and closing one end of said cylindrical valve seating, said deflector and said housing forming between them said channel for causing the fluid to flow radially into said valve.

3. The combination with a high lift safety valve as claimed in claim 1, of an escape chamber associated with said valve adjacent said outlet ports, said escape chamber having a lateral outlet to assist the fluid to escape through said outlet ports at right angles to the valve axis.

4. The combination with a high lift safety valve as claimed in claim 1, of an escape chamber associated with said hollow cylinder adjacent said outlet ports, said escape chamber having diametrically opposed outlets to assist the fluid to escape through said outlet ports at right angles to the valve axis.

5. The combination in a high lift safety valve, of a valve comprising a hollow cylinder with inlet and outlet ports therein, a part closing one end of said hollow cylinder (and not in the path by which fluid passes through the valve) to which valve-lifting fluid pressure is applied, and a closure for the other end. of said hollow cylinder; a cylindrical valve seating surrounding said hollow cylinder and controlling the flow of fluid to and from said inlet and outlet ports respectively, a valve stem, compression spring means to load said valve, thrust links transmitting said load to said valve stem to hold said valve upon said cylindrical valve seating, and a housing with inlet and outlet branches and having a channel for delivering fluid to said part of the cylinder and a separate channel for delivering fluid radially to said inlet ports when said valve opens, the fluid flowing radially into and out of said valve and having its direction of flow altered by the two ends of the cylinder so that the flow has substantially no influence upon the valve movements.

6. The combination with a high lift safety valve as claimed in claim 5, of a cross head upon which said compression spring means are mounted, and having a central member carrying an abutment, a yoke connected to said compression spring means and also having an abutment thereon, an abutment member on said valve stem, and an abutment member on said housing, said thrust links being disposed obliquely between said abutments to transmit the spring load to said valve stem.

'7. The combination with a high lift safety valve as claimed in claim 5, of a cross head upon which said compression spring means are mounted and having a central member carrying an abutment, a yoke connected to said compression spring means and also having an abutment thereon, an abutment member on said valve stem, an abutment member on said housing, and locating members on said abutments and abutment members, said thrust links having knife-edged and slotted hooked ends engaged by said locating members and being disposed obliquely between said abutments to transmit the spring load to said valve stem.

8. The combination with a high lift safety valve as claimed in claim 5, of a cross head upon which said compression spring means are mounted and having a central member carrying an abutment, a yoke connected to said compression spring means and also having an abutment thereon, an abutment member on said valve stem, an abutment member on said housing, and a screw bolt upon said central member for adjusting the compression loading effect of said compression spring means, said thrust links being disposed obliquely between said abutments to transmit said compression loading effect to said valve stem.

MAURICE WALTON TUDSBERY TURNER.

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