US1793659A - Angle blow-off valve - Google Patents

Description

Feb. 24, 19311 w. 6. WILSON 1,793,659

' "ANGLE BLOW-OFF VALVE Filed Aug. 31, 1926 2 Sheets-Sheet 1 I /Z n U 4 j a 5. F

Feb. 24, 1931. w. G. WILSON ANGLE BLOW-OFF vKLvE 2 Sheets-Sheet 2 Filed Aug. s1,v 1926 Z 0 i M r 0, W. 5

Patented Feb. 24, 1931 neural) STATES PATIENT orFicr.

WYLIE 6. WILSON, or JERSEY CITY, new .rERsEY, ASSIGNOR TO EVERLAS'IIING VALVE COMPANY, or JERSEY CITY, NEW JERSEY, a CORPORATION or NEwJEBsEY ANGLE BLOW-OFF VALVE Application filed August 31, 1926. Serial R0. 132,840.

'. This invention relates to valves, particularl v blow-off vaIves for steam boiler service, of the angle-type. As is well known, the blow-off valve is from 6 time to time opened'to withdraw boiler water which has become too dense, and is also used to empty the boiler when desired; the valve being connected to the drain line at the level of about the lowest point in theboiler.

The blow-oil valve thus is required to withstand probably more severe service conditions than almost any other valve. In the first place, the fluid being discharged by the valve passes from a confinement at high pressureto a zone at atmospheric pressure merely. Naturally, the velocity of the fluid through the valve is high, as an accompaniment of the pressure drop. Such pressure reduction is precipitous, and represents an enormous force; especially where the drop is considerable, as in the case of high pressure boilers, in connection with which the present invention is of great value. The out-rushing fluid ordinarily carries in suspension par-- ticles of sharp, gritty matter of'a highly abrasive character. There results what may be termed an abrasive scour of parts of the valve interior, particularly at the valve seat and its environs, but with seri- 80 ous scour also at other parts of the valve, especially where the valve is an angle-type valve, and the body or casing presents an abutment surface for the fluid stream to cause the latter to make approximately a right-hand turn to approach the valve outlet.

One of the objects of'the present invention is to provide a valve bodv or casing having an abutment surface of the kind lastindicated, wherein such abutment forms a casing-wall 40 subdivision and wherein such casing-wall, at

said subdivisions and its neighboring subdivisions, is so designed-as to prolong the safe life of the valve. By safe life. is meant the number of high-pressure stream-discharge hours to which the valve may be subjected in service before the point is reached where there is no longer. present the proper factor of safety, against valvebreakage and thelconsequent danger of scalding an attendant. I have found that according to the prestight valve closure.

ent invention,

the new valve may have a very long safe life,

if the abutment surface and the neighboring wall subdivisions are prop erly proportioned as to the average masses of the abutment and the neighboring wall subdivisions, to give a considerable average thickness to the abutment wall subdivision. I prefer to rovide such mounting for the abut ment sur ace wall, by employing solely therefor the aforesaid neighboring wall subdivisions and by making the latterof a certain thinness as'compared with the thickness of the wall subdivision carrying the abutment 7 surface.

Another. object is to provide a valve Where 1n the scalding faces at the valve outlet are protected against scour by the impact of the fluid being discharged under high velocity while carryin abrasive matter insuspension. Another ob ect is to provide a valve wherein means are incorporated for preventing the trapping or pocketing of gritty accumulations the vicinity of the which the movable valve member is seated;

may not interfere with tight closure at any valve closing operation .and at the same time may not damage any of the sealing surfaces in such a way as to interfere with a tight closure at a subsequent valveclosing operation.

Another object is to provide an angle valve wherein the valve member carries a sharp edge which seals against the valve seat, but wherein said edge and seat are protected against non-tight valve closure, as the result of side thrust of the fluid against the stem or other movin 'valve part. Another object is to provide a valve wherein a plurality of sealing faces are carried by a movable valve part, which faces coact with other faces for conjoint action in efiecting Various other objects and advantages of the invention will be specifically pointed out or will be apparent hereinafter, in the course of a description of a preferred one of the various possible forms of the invention as shown in the accompanying drawing; it being understood, of course, that such form is merely illustrative of one combination and arrangement of parts calculated to attain the objects of the invention, pursuant to present preference, and hence the detailed description of such form now to be given is not to be taken as at all defining or limiting the invention itself. That is to say, the scope of protection contemplated is to be taken solely from the appended claims, interpreted as broadly as is consistent with the prior art, and with explanatory references to the specification only where a claim is ambiguous or to be impliedly limited be avoid such are in or said claim.

In the accompanying drawing:

Fig. 1 is a view showing the valve stem in ond its express terms to er to save the validity of side elevation and other parts of the valve in a section which is axial to the inlet and outlet openings or ports;

Fig. 2 is a fragmentary view,.showing certain of the parts of Fig. 1 on a slightlyenlarged scale, but showing the valve only partly closed.

' Fig. 3 is a horizontal cross sectional view through the casing.

The valve illustrated includes a fixed structure and a movable structure; the former including a valve casing 8, and the latter a valve stem 4, a valve head 5, a valve-closing ring 6, a threaded retainer 7 for said ring, and a threaded plug 8 sleeving the lower end of the stem above its terminal enlargement 9.

The valve casing 3 is in the main a unitary Y casting, including an inlet 10, an outlet 11, and

a casing proper incorporating a plurality of wall subdivisions 12 and 14.

The wall subdivision 12 presents inside the valve'casing an abutment surface for giving the steam traversingthe valve a right-angled change of direction, to direct the steam to make egress from the casing through a fixed member 15 having an upper cup 16 and a reduced bore opening into the valve outlet 11.

Wall subdivision 12 is of a considerable thickness at its central part shown in section in Fig. 1; said wall 12 being reduced in thickness so as to blend smoothly into the side walls 14. Preferably, these side walls are of about the thickness indicated at 14:, from the points where they spring away from the plane containing the inner end of inlet 10, to the point, such as that indicated at 1411, where they begin slightly to swell in the thickness to merge with the thickened subdivision 12. It will be noted that according to this arrangement each of the comparatively thin wall subdivisions 14 has a rather considerable horizontal line of curvature as compared with the similar line of the more massive" subdivision 12 carrying the wear from the abrasive action of gritty particles in the fluid stream impinging against and deflected by the abutment-surface 12a. In practice, I have found it desirable'to roportion the thicknesses of these wall sub ivisions so that the maximum thickness of a subdivision 14 is approximately 5/7 of that of the subdivision 12.

The fixed member 15 is threaded into the valve casing as indicated and so as to make a fluid tight seal between itself and the easing, by compressing a ring gasket 17 p The sealing ring atively small in cross-sectional area, with the cross-sectional shape of the ring substantially that of a diamond. This shape produces an upper edge 6a and a lower edge6b, each in a single plane, with both planes parallel, and parallel to the plane containing the bottom wall of the cup 16 which carries the seating surface for the edge 6?). The cup bottom wall, further, is parallel to the surface forming the roof of the annular recess 18 within which the ring is positioned and retained, but not tightly held, being loosely mounted so as to permit of slight play, by

pending from the valve head 5 and by sur face contact with the conical rim portion of 6 is illustrated as relsurface contact with a cylindrical rib 5a dey a bottom enlargement on retainer 7. The; .1:

precise cross-sectional shape of the ring is relatively unimportant. The

tional area and sharp edges on both sides of the ring. In order to obtain a ring which shall operate according to the invention, in

cluding the ability to be shaped to present and retain for a considerable length of time important 1 features are comparatively small cross-secv edges on opposite sides of exceeding sharpand thus have movement relative to the other parts of the movable valve structure during the final downward squeeze of the valve stem in closing the valve. The required right closure of the valve is obtained by the line contact of the edge 6?) against the bottom wall of cup 16 and the line contact of edge 611 against the annular surface forming the roof of recess 18.

I havefound that when a sealing edge such as that shown at Ga or 6b is used, that is, a

sealing edge on a ring, an effect is produced cally rounded lower face,

dom of which it contacts. For instance, I'have test- I ed such a valve construction as that illustrated, wherein the sealing faces were not ground at all, and simply used as they were turned 'on the lathe; and I found that the valve was tight not only under lbs. pressure, but also tight under 250 lbs., and even 500 lbs. I made not only one test but a multipliclty of tests with the same valve; and I found the seal had a tight life which was more than 40 times the tight life of a high grade standard valve with relatively wide coacting faces on disc and seat, when controlling steam at 500 lbs. pressure. Tight closing of the valve as just described I found could always be relied on merely by applying hand power, multiplied by the common screw thread connection between the valve stem and hand wheel, with such hand wheel of the usual diameter. Fur ther, where grit is likel to be present, I find that the sharp edge pushes the grit aside and forms a clean metal-to-metal seal, while relatively wide faces crush the grit between them and cause leakage.

An important feature of the .lustrated valve in this latter connection, is the mounting of the valve head loosely on the stem 4. This loose 'mount is obtained by having the plug 8 sleevethe stem with some looseness, by shaping the enlargement 9 to have a spheriand by housing such enlargement loosely in chamber '19 roofed over b the bottom of plug 8 and having a plane ottom wall 56, preferably parallel to the plane of the ring edges 6a and 6b. The result is that when the valve is almost closed and the edge 66 is forcing its way through a grit collection in the have a plowing or sweeping action on the grit. This looseness of mount of the valve head on the valve stem, the retention of the ring on the head to give the former slight freemovement, and the capacity of the ring to flex definitely in different portions, all coact to insure tight valve closure, to give long life to the valve, and to accomplish these results regardless of the presence of grit between the relatively moving valve parts. Such a result is of course contributed I to in an important degree by the arrangement substantially perpendicular line of movement of the valve whereby the substantially uniplanar edges 6a and 6b and the surfaceswith which they contact are all substantiallyparallel and to the general head toward and away from the outlet 11.

Theoretically, an arrangementof the kind '1 hereto.

the permissible degree of ing the valve-head bottom of cup 16, someside sway is possible and the edge 66 may side-play of the latter,

ceding would not seem to require a guide for the valve head; even though such a guide I the type of valve heretofore I is required in constructed where the coacting sealing elements of the valve member and seat are'both relatively wide surfaces.

that, due to theloose mounting of the valve head on the valve stem, the inrush of fluid acts transversely'of the head to throw the latter at a slight angle to the horizontal at aboutthe instant the edge 6b contacts with with, becomes clamped tighter and tighter thereagainst at a fixed angle ofinclination In other words, 1n the absence of a guide or-some equivalent restraining means 7 Actually, however, have found that to produce a practical valve of the type herein disclosed, it is apparently necessary to provide a guide for the valvehead. I have found in this connection lnstead of sliding slightly across saiddescribed in' the paragraph immediately preto hold the Valve head against a greater than side-sway, the-re'is not the required side-sway in one direction, the direction of approach of the fluid stream toward the surface l2a,'and there is a fatal excess of side-sway in the opposite direction. I have found that best results are apparently. obtained when, at the instant of sealing contact, the head is held to dispose the edges 6a and 6?) almost parallel to the plane of the surface in the bottom of cup 16.

This guide Iprefer to provide by constructas a cylindrical piston working in the cup 16 as a cylinder. When the valve is closed, as in Fig. 1, the peripherthe valve is opened wide, the valve-head is,

of course,'well above the top of cup 16. Nevertheless, when the ing position. The fit of the stem 4 in the head, while loose enough to permit some close to cause the head to make such entry.

As the head travels down in the cup, the wide portion 50 and the fit of'the same in combine to induce parallelism of j the clip,

the elements 66 and 21 prior to their ac, tual contact. Also,

pressure allaround the valve-head at the level ofsuchpoint.

Consequently, the plane of the edge 6b is is still sufficiently the head properly enters the cups head is moved toward 'valve-clo'sthe instant the relation of the parts shown in Fig. 2.is established, constriction of the fluid stream at the point 20 tends to equalize the Said guide, in the present instance, forms a part of a means having important operative features, in that said means functions to revent the accumulation of grit or other oreign matter anywhere within the cup 16 and on the workin parts on or carried by the valve-head at its underside, as well as I to prevent damage from "the wire-drawing I sions of such seat, one smoothly blending into The operation of said means effect common to most if not all'high-pres-' sure steam-valves as heretofore constructed' Said means is carried partly by the valvehead 5 and partly by the cup 16, more particularly as shapings thereof. The cup comprises an upstanding cylindrical wall which curves into the flat seating surface surroundmg the outlet port. Thus, on both sides of the limits of the possible edge contacts of the ring 6 with the bottom of the cup, that is, on both sides of the real valve seat for the edge 6?), there are extensions of such seat imperceptibly merging therewith but considerably increasing the width of the same; said seat and both these extensions being uniplanar and parts of the cup bottom. In addition, there\ are further outward extenthe other and the latter smoothly blending into that one of the first-mentioned exten-- sions outside said valve seat; such further outward extensions bein that indicated at 22 in Fig. 2, and beyon" it, the cylindrical sidewall of the cup 16.

As to the valve head 5, note that beyond the fifth side, or outercylindrical wall, of the ring 6 which is engaged by the inner cylindrical surface of the depending rib 5a, the valve head has first some increase in diameter, due to the thickness of the said rib, then maintains this diameter for some distance above the bottom of the rib, until the bottom of the enlargement 5c is reached, and then the head has a greater increase in diameter, which latter diameter is maintained until the top of the enlargement 5c is reached.

Note further that the distance up along the rib is less than the distance up along the enlargement. Note also that the ring 6 has considerable protrusion below the bottom of the rib. The arrangement is such that with the parts as shown in Fig. 2, the bottom of the enlargement 50 is well above the bottom of the cup 16. In other words, when the enlargemeiit has just entered the cup, as shown in Fig. dicular istance from the flat'bottom o the cup than the outer cylindrical surface of the depending rib 5a is spaced in a radial direction from the cylindrical wall of the cup.

is as follows:

.ing of 5c and 16, the large 2i the edge 6?; is at a greater per enhad proceeded as far as shown in Fig. 2. No more grit can flow 'into' the cup 16; but of course fluid can. This fluid flows throu hthe constricted opening at the point 20, and t ence as indicated by the arrows of Fig. 2. Conse- 50 and cup 16. The cross-sectional area of.

the passage between elements 66 and 21 is much greater than between 50 and 16. When- 66 and 21 approach each other so that the space between them is the same as the spacsurface or wide face of head portion 50 then overlapped by the side-wall of cup 16, causes constriction of the fluid stream and protects elements 6 and 21. When the head first enters the cup, however, there is greater spacing between the bottoms of elements 50 and 16 than between the bottoms of element 5a and 16; and as a result, any grit under the element 50 is Assume that the valve closing operation washed out by the fluid flow throu h a free and unrestricted outlet. Thus it wi 1 be seen that the movable valve-closing structure with the walls carried thereby are so related to the chamber 16 with its chamber walls as to continuously provide, during movement of the valve sealing element 6 toward con-.

tact with the bottom of the chamber 16,'a assage for the valve-traversing fluid, which ecreases in cross-sectional area toward the port 11.

Finally, due to the fact that the bottom of the enlargement 50 on the valve-head is set well above the, edge 6?), such edge is always shielded from constricted fluid washing irectly across the same.

Inasmuch as many. changes could be made in the above construction, and many apparently widely different embodiments of my invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense. g

It is also to be understood that the language contained in the following claims is intended to cover all the generic and specific features of the invention herein described and all statements of the scope of the invention which as a matter of language, might be said to fall therebetween.

I claim:

1. In a valve, the combination of a fixed structure presenting a'valve port and an encircling substantially uniplanar surface 1ncluding a valve-seat, and a valve closing struc ture movable in a line substantially perpendicular to such plane, said valve closing structure including a support and a valve-head presenting a substantially uniplanar .surface means for floatingly mounting the valve-head on said support and maintaining the last-.

ring-shaped sealing element, means for rementioned surface substantially parallel to the similar surface ofthe fixed structure as the valve is about to be closed,'a flexible sealing element having relatively sharp edges on opposite sides, and means for holding the element with some looseness on the valve-head sothat the valve is fully closed by squeezing said element between, and said edges tlght against, the uniplanar surfaces of the two structures.

2. In a valve, a stem, a valve-head on said stem and rockably mounted thereon, a flexible taining the element on the head While permitting a part of the element to move relative to another part thereof, said ring being shaped to present a sharp edge beyond the head and in substantially a single plane perp'endicular to the axis of the stem, and a fixed structure carrying opposite said plane and substantially parallel thereto a substantially I flat surface for engaging said edge by line contactwhen the valve is closed, said fixed edge, means for giving a closing movement to said valve-head along a line perpendicular to said planes, and meansfor retaining the closing member on the valve-head to insure contact between said edge and the fixed structure within the confines of said surface, while ermitting parts of said member to be flexe as said closing movement nears completion.

4'. In a valve, the combination of a movable valve-head, a fixed structure forming part of the valve casin and having a through port, said head and t e fixed structure each carrying substantially fiat surfaces, the surface on the fixed structure encircling the port,'means for guiding the direction of travel of the head during closing of the valve to maintain said surfaces substantially 'parallel yet variable from parallelism within given limits, a valveclosing ring of flexible material shaped to present sharp edges at opposite faces of the ring, the stralght line which cross-sectionally of the ring joins said edges being substantially parallel to the direction of travel of the valve-head under control of said guiding means, and a ring-retaining means on the head for holding the ring for travel with the headwhile holding the ring edges and the surface on the head substantially parallel" yet variable from parallelism within given limits.

5. A valve-closing member for mterposition between opposed surfaces on relatlvely movable valve parts, comprising a ring of hard elastic material and having a cross section substantially diamond shaped but with against both surfaces when the valve is fully.

closed, and means for retaining the member on the head.

7. In a valve, the combination of relatively movable valve-head and valve-port structures, afiexible valve-closing member to be clamped tight between said structures to close the valve against high pressures, means for insuring such tight closure including a surface carried by the valve-port structure, said member having a sharp edge to coact with apart of said surface, said memberbeing mounted in one of said structures so as to permit a gritlowing action of said edge during closing 0 the valve.

8. In a valve, the combination of a structure forming part of thevalve casing and having a port surrounded by an annular surface, said structure also being shaped to provide a chamber 0 ening away from the port mouth so that a ottom for said chamber is formed by said surface, a valve-closing structure, a valve-sealing element carried by said' structure, said valve-closing structure being movable at right angles to the plane of the port mouth to position said element to contact with said surface to cause closing of the valve, the walls of said chamber and the walls of the valve closing structure being so shaped and related to each otherthat during movement of said element toward contact 'with said surface, the passage between said walls for the valve-traversing fluid will decrease in cross-sectional area toward the mouth of said port, said valveclosing structure including a part adjacent to and surrounding said element and another part of greater cross-sectional area loosely slidable in said chamber during closing movement of the valve-closing structure.

9. In a valve," the combination-of a structure forming part of the valve. casing and having a port surrounded by an annular surface, said structure also being shaped to provide a chamber opening away from the port mouth so that a bottom for said chamber is formed by said surface, a valve-closing structure, a valve-sealing element'carried by said structure, said valve-closing structure being movable at right angles to the plane of the port mouth to position said element to contact with said surface to cause closing of the valve, the walls of said chamber and the walls of the valve closing structure being so shaped and related to each other that during movement of said element toward contact with said surface, the passage between said walls for the valve-traversing fluid will decrease in cross-sectional area toward the mouth of said port, said valve-closing structure including apart adjacent said element of ,less cross-sectional area and a part thereabove of greater cross-sectional area, the latter part shaped to slide within the chamber loosel during closing movement of the valve-closing structure.

10. A valve whereof the casing has inlet and outlet ports and wherein said casing is shaped to provide a passage through the valve and to present a part of said casing .as an impact and change-direction surface intermediate said ports for a high velocity high pressure fluid, said surface being carried by the casing wall and being of greater thickness than the walls of the casing which guide the fluid toward and away from said surface.

11. The valve defined in claim 10, wherein the walls last-mentioned are imperceptibly blended with the wall carrying said surface, as the result of gradual increases of thickness of the surface-carrying wall and gradual decreases of thickness of each of the other walls.

12. A valve comprising a casing having a discharge passage formed therein and a fiat valve seat surrounding the discharge passage, a cylindrical wall surrounding and extending above the seat, the surface of the cylindrical wall being curvingly merged into the surface of the seat.

13. A valve comprisingea casing having a discharge passage formed therein, a removable element secured to the casing and formed with a discharge port in alinement with said discharge passa e, the removable element being formed wit a fiat valve seat surrounding said discharge port, a cylindrical wall formed on the removable element surround-.

ing and extending above the seat, the surface of the cylindrical wall being curvingly merged into the surface of the seat.

' 14. A valve comprising a casing having a discharge passage formed therein, a removable element secured to the casing and formed with a discharge port in alinement with said discharge passage, the removable element being formed with a flat seat surrounding the port and with a cylindrical wall surrounding and extending upwardly and lying wholly above the seat, and .a valve head discharge passage formed therein, a removable element secured to the casing and formed with a discharge port in alinement with said discharge passage, the removable element being formed with a flat seat surrounding the port and with a cylindrical wall surrounding and extendingmpwardly and lying wholly above the seat, and a valve head adapted to fit into the cylindrical wall with a clearance that is less than the vertical height of the cylindrical wall, said head carrying a part adapted to form a seal against said seat.

16. A valve com rising a casing having a discharge passage ormed therein, a seat surrounding the discharge passage, a cylindrical wall surrounding and extendin above the seat, a valve stem, a head carried by the stem,

a restricting wall carried by the head and adapted to fit loosely within the c lindrical wall ofthe casing, an annular face ormed on the head below the restricting wall, 'and a sealing member projecting from the annular face and spaced inwardly from the restricting wall, the sealing member being adapted to form a seal against the aforesaid seat.

17. A valve head structurecomprising a stem, 21 head carried by the stem, an annular face formed on the lower side of the head, a circular flange projecting from an intermediate part of the annular face, a sealing ring within'the flange, saidsealing ring having a fiat face engaging thev inner side of the circular flange, a sharp corner next to the annular face, a sharp corner extending away from the annular face and projecting below the flange, and means for holding the sealing ring in position.

18. A valve head structure comprising a stem, a head carried by the stem, an annular face formed on the lower side of the head, a circular flange projecting from an intermediate part of the annular face, a sealing ring of hard elastic material within the flange, and means for holding the sealing ring loosely in position for contacting with the annular face and with the inner side of the circular flange.

19. A sealing member for interposition between opposed surfaces on relatively movable valve parts comprising a ring having a sharp upper edge, a sharp lower edge directly below the upper edge, and an outer peripheral surface substantially parallel to a line joining the upper and lower edges.

In testimony whereof I afiix my signature.

WYLIE G. WILSON.

Ill

' ,ifadapted to -fit' into close proximity to the cylindrical wall,- said head carrying a part I 'ag'aadapted to form aiseal against said seat.

1 P "'.-.--15$ A- valve boniprising a casing having a

Images