US1726274A - Valve - Google Patents

Description

'Aug. 27, 1929. J. c. MELooN VALVE Filedv sept. 24, 1925 rea-aaai a7, ieee UHTED STATES PATENT JONATHAN C. MELOON, 0F PROVIDENCE,

RHODE ISLAND, ASSEGNGR TKG GENERAL FIRE EXTINGUISHER COMPANY, OF PROVDENCE, RHODE ISLAND, A CORPORA- TlON 0F DELAWARE.

Application led September This invention relates to improvements in valves. More particularly it relates to anticolumning improvements in differential dry pipe valves in which a liquid, usually water, under pressure, is held in check by a less pressure of air thereupon, as in sprinkler systems. Valves of this character are ordinarily provided with a movable valve inember having one side (known as the air face or air clapper) of considerably greater working area than the other, (known as the water face or water clapper) thus permitting a relatively small pressure per square inch on the side having the large working area to hold the valve member on its seat within the casing against'a greater pressure acting on the side having the smaller working arca. In sprinkler systems for buildinos the sprinkler heads and distribution pipes are connected to the side of the valve having the large working area, the air in the pipes acting'on said area, and the water supply is connected to the side having the smaller working area, exerting a pressure on that area. When a sprinkler head opens, the air in the distribution pipes rushes out, thus lowering the pressure in the valve and permitting the opening thereof under pressure of the water. The sudden rush ol water into the distributing pipes of the system containing air which acts as an elastic cushion, together with the slow rate of escape through the open head or heads, causes a surge back to the valve which may result in the closing of the valve. At any such time the weight of the column oit' water in the riser on the sprinkler side of the valve tends to hold the valve closed; and this tendency is magnified by the differential character of the valve, so that the pressure from the supply main may be insuiiicient to reopen the same valve, producing a condition known as columning7 of t-he valve. Under these circumstances the sprinkler system would be locked in inoperative condition. rihe preventative is to provide an opening which becomes effective to permit equality ot pressures on the dry pipe valve, by permitting free passage of liquid by either clapper to the other, after it has once opened, and this general principle has long been known.

It is an object of the present invention to provide an improved means within valves VALVE.

24, 1925. Serial No. 58,301.

oi this class which will vprevent columning ai'ter initial opening of the valve. In particular the invention provides an anti-columning device which is positively operated by the high pressure of the supply; one which is an auxiliary valve thaty while waiting ready t'or operation is held tight-ly closed by the air pressure acting through the dif- :terential valve; one whose leakage, if any, does not diminish the air pressure; one which is selil adjusting so as to become closed in synchronism with the closing of the main valve; and one whose opening, when it occurs, is so disruptive that its closure cannot be ite-established except by the intervention of human intelligence.

These objects are attained by providing the ordinary differential dry pipe valve with a passage leading from the supply inlet directly to the intermediate chamber of the valve. This chamber is ordinarily in direct communication with the atmosphere and has a drain for leaking water. The said passage has the anti-columning valve, normally held closed by the pressure of the main valve member, but released when said member opens. lVhenever such'a release occurs the main Water supply pressure forces the anticolumning valve open, thrusting it out of the passage, and a spring pulls it to one side where it falls in a lateralr pocket, so that both gravity and the said spring prevent its accidental return to its seat. Thus, simultaneously with the opening of the main valve, a permanent passage is opened from the supply to the rintermediate chamber, opening it to the pressure of the supply and preventing the restoration ot the differential characteristic of the valve, in case the main valve should close, for the supply pressure can thereafter act upon a surface as large as that on which the water column may rest. This converts the dry pipe valve to a mere one way valve, which can always open when there is upwardk pressure enough to lift its mere weight.

One manner of applying the invention is illustrated in the accompanying drawings, it being understood, however', that the saine may be applied in various ways. It is intended that the patent shall cover by suitable expression in the appended claims whatever features of patentable novelty exist in the invention disclosed.

In the drawings: 1. rigure 1 is an elevation, in medial sec- `tion, of a valve embodying the invention;

Figure 2 is an elevation in section through the auxiliary valve mechanism;

Figure 8 is a plan in section on the line 3-8oi` Figure l showing the auxiliary valve in closed position; and

Figure 4: is a similar view showing the auxiliary valve in open position.

Referring to the drawings, the numeral indicates generally the casing ol: a difierential valve, having a supply inlet 12 at one end and an outlet 14- to the distribution riser of a s arinkler system at the other end. The inlet passage extends a substantial distance within the casing and has on its inner end a valve seat 16 adapted to be engaged by the under side oi3 a valve disc 18 pivotally mounted as at 20 within the main casing. A gasket 22 on the under side et the valve disc engages the valve seat 16, to make a watertight closure when the valve disc 18 in closed position. Above the valve. disc is a chamber 2a having in the margin ci' its bottom a valve seat oil considerably greater diameter than the seat 16; and against this the rubber edge 32 oi the disc seats so that the fluid in the chamber exerts its pressure upon the entire surface area et the valve disc 18, permitting a relatively small pressure per square inch on the upper side to retain tle lise upon its seat; against the greater pressure per square inch of the water applied to the restricted area on the under side. Between the seats oi' these two valves is the intermediate chamber 28 which while the valves are closed is open to atmosphere through the customary drip pipe 26 which may be equipped with any suitable valve, .tor permitting a small flow of water to escape, and tor closing at inception oi: the large flow which occurs when the main valve opens, many devices for which are known. Extending from the supply inlet 12 to the intermediate chamber' 28 is ley-passage 311., and this passage has in its upper end an auxiliary valve casing 36 the upper end of which forms a valve seat 38 for an auxiliary valve 40. A gasket 42 on the under side or' the valve 40 presses on the valve seat 88. rlhe main valve disc 18- holds this closed. lt exerts its pressure upon the spring top ci this auxiliary valve el), which has two ply dome o1e convex discs lll ot' resilient inaterial, such as brass. These areadapted to yield stitlly, sutlicicntly to permit of the main valve disc 18 engaging them betere it is itself seated, after which it depresses them until it comes to its seat 16; and these discs are still enough to hold the valve 40 thereafter close-d against the water supply pressure. The intermediate chamber 28 is conveniently made in the form of a circular groove, in which there extends radially from by a Cotter pin er the like.

the auxiliary valve casing 36 a fixed bracket 52 in which there slides radially a rod 50 whose inner end is attached by yoke i8 to the valve 40. Beyond the upstanding portion 522L of the fixed bracket 52, through which the slidable radial rod passes, there is a coiled spring strung on the rod, and out side ot that is a washer' 54- retained thereon The spring 56 exerts pressure tending to thrust the rod outward, carrying the valve -.O to the removed position indicated by dotted lines in lfigure 2 of the drawings; and this movement is normally restrained, when the valve is closed, by the latching engagement out the central part of the valve l() within its seat 88a When the said valve is unseated by the Water pressure, simultaneously with the opening ot the main valve, it is pulled away by rod 50. Thereafter, if the valve disc 18 should close, water in the interi'nediate chainber 28 would be ot the same pressure as in the supply which, acting upon 'the entire area or' the valve disc 18, would prevent permanent closure by a water column.

lllhen the dry pipe valve is set ready for action, the full pressure of water supply 'tends to open the by-passage to intermediate chamber, and this is normally so great that no possible sticking of the valve l0 can withstand such an opening pressure whenever this valve is tree to'open. But while thus waiting the valve is held closed by the superiority of total air pressure over total water pressure in the main valve and by passage and thus is held securely closed and very tight against leakage, by a force which disappears Whenever the main valve actually opens. 'lhe attainment of this tightness would be a. diiiicult matter and a rare occurrence but tor the provision of the spring head 4A, because ot the practical diliiculties in the way et making two absolutely rigid valves seat at the same instant, such as the valve seat and valves 16, 22, 40, 38. But by making the shell fractions 44 concave,` and su'liiciently deep to extend, as regards their position of possible working travel, through the range ot variations which may arise in the relations of the actual valve seats 88 and 16, and through the variation possible commercially in the thickness of the valve 4,0, a construction results in which the valve l() becomes tightly seated whenever the valve disc 18 is seated at 22 on 16. The dome spring la is stable against overturning when vertically compressed and by being made in two or more ply of metal is sui'iiciently flexible as well as suiiiciently sti to serve the purposes of the apparatus. Any leakage which may occur notwithstanding the provisions does no harm to the system, for it is not a leakage of stored air but rather of supply water into the intermediate chamber from which a drain is already provided,

llO

When the dry pipe yvalve works, the valve 4() is thrust violently open, and if it Were left loose and free the chance is very small indeed that it would ever fall in position to close the opening 34:, and be held down thereon, it the clapper 18 should subsequently be swung shut. But conceivably it might fall so as to overlie the edge of thevalve casing 36, in which case it would constitute a barrier preventing the closure of the valve 18 and thus would act as a mechanical obstacle or latch preventing water-columning. But by so doingthe parts might be injured in some way and it is therefore considered better practice, and the invention provides, for the complete removal with certainty of the valve 40 from its casing 36, thus permitting the valve 1S to close and open again as many times as surges may move it, while leaving the valve 40 in position to be reset by the inspector. 1t will be understood that the valve body 10 has a suitable hand hole for observation of the interior and for manipulation of the parts, which may be assumed to be in the portion of the valve not shown in Figure l. When the valve is to be reset, it need only be placed in the posi-a tion illustrated in Figure 2, whereupon its slight engagement in the interior of the valve casing 36 will latch it against pull oia the spring 56. And Whenever it is open the pull of this spring vvill hold it in the trough of the chamber 28 Where it cannot be in the path of the clapper 18 of the main valve.

1V hat I claim as my invention is:

l. The combination with a supply system valve casing having a Waterway therethrough and an intermediate chamber, oic a closure seating across said Waterway and cutting oil said chamber from the system; a by-passa-ge from the system side of said closure to the chamber; a valve for the by-passage adapted to be opened by the system pressure when the closure is ope-ned and held closed by the closure when the latter is normally closed; and means operative upon the opening ot said valve to withdraw said valve out of the path of movement of said closure whereby the said by-passage remains open notwithstanding subsequent abnormal closing of the closure.

2. The combination with a differential valve having an intermediate chamber, of a lay-passage from one side of the valve to said chamber; an auxiliary valve for the by--passage held closed by the main valve when the latter' is seated7 and adapted to be opened by the pressure in said by-passage when the main valve is unseated; and means operative upon the opening of said auxiliary valve to withdraw it to a position beside its seat and out of the path oif movement of the main valve whereby the said by-passage remains open notwithstanding subsequent reseating ci? the main valve valve to the intermediate chamber; an aux iliary valve closing the by-passage when the main valve is closed, held closed by the main valve when the latter is closed, and adapted to be opened by the supply pressure when the main valve is opened; there being means adapted to move said auxiliary valve after its initial opening laterally from its seat and out of the path of movement of the main Valve, thereby to prevent its being reseated upon the subsequent closure of the main valve.

4l. The combination with a differential dry pipe valve having an intermediate chamber, of a by-passage from the inlet side of the valve to the intermediate chamber; an auxiliary valve closing the by-passage when the main valve is closed, held closed by the main valve when the latter is closed, and adapted to remain open after the latter is opened notwithstanding subsequent closure oi the latter; there being a compression spring intervening between the two said valves when closed, having travel enough to cause their engagement notwithstanding variations in relative positions of valve seats, and having strength enough to resist opening by the supply pressure; and means operative upon the opening of the auxiliary valve to move said compression spring out of the path oi" movement of said main valve thereby to prevent the latter from reseating the auxil iary valve.

5. The combination With a diii'erential dry pipe valve having fin-intermediate chamber, of a by-passage from the inlet side of the valve to the intermediate chamber; an tuxiliary valve closing the ley-passage when the main valve is closed, held closed by the main valve when the latter is closed, and adapted to remain open after the latter is opened notwithstanding subsequent closure .of the latter; there being a dome spring in tervening between the t-Wo said valves When closed, and means operative upon the opening of said auxiliary valve to withdraw said spring out of the path of movement oi said main valve.

6. The combination with a differential dry pipe valve having an intermediate chamber, of a by-passage from the inlet side of the valve to the intermediate chamber; an auX- iliary valve closing the by-passage when the main valve is closed, held closed by the main valve when the latter is closed, and adapted to remain open aiiter the latter is opened notwithstanding subsequent closure of the latter, there being means tending constantly to move the said auxiliary valve away from its seat and said auxiliary valve being arranged to constitute a latch whereby said auxiliary valve is restrained from being unseated by said means so long as said auxiliary valve remains closed.

7 The combination with a differential dry pipe valve having an intermediate chamber, of a lay-passage from the inlet side of the valve to the intermediate chamber; an auxiliary valve held closing the same when the main valve is normally closed and adapted to be opened by the supply pressure when the main valve is opened; and means secured to the said auxiliary valve adapted to move it away from the by-passage and out 0i the path of movement ot the main valve upon said auxiliary valve being opened.

8. The combination with a differential valve having an intermediate chamber, of a by-passage from the inlet to the intermediate chamber; an auxiliary valve in said chamber closing said by-passage by movement in the direction of closing travel of the main valve, and held closed by said main valve when the latter is closed; there being means operative when said auxiliary valve opens for moving and retaining said auxiliary valve away from the by-passage in a direction transverse to the direction o1 closing travel of the main valve, whereby closure of the main valve following the said transverse movement of the auxiliary valve can not eilect closureof the by-passage.

9. The combination in a valve adapted to be held closed by air pressure exerted upon a relatively large surface area against a greater water pressure exerted upon a relatively small surface area, of an intermediate chamber encircling the water passage; a

duct to said chamber from the inlet side of thevalve casing; a' valve for the duct, set in the chamber, held closed by the main valve when both are closed, and means set in the chamber to move and hold the duct valve away from the duct when the duct valve is open.

l0. A valve having an inlet passage, an outlet passa-ge, and an intermediate chamber; a closure cutting oiln said chamber from said passages and closing said valve when seated; a by-passage from one of said cut oil passages to said chamber; a valve in said chamber closing said by-passage and being held closed by the said closure when seated; and means in said chamber' operative upon the unseating of said closure for withdrawing said valve from its seat to a position where subsequent seating of the closure can not effect reseating of said valve.

11. A valve having separated valve seats and a chamber intermediate thereof; a closure seating on said seats; a passage leading to said chamber from a source of pressure; a valve closing said passage, held seated by the closure when seated and adapted to be opened by the pressure in said passage upon the opening oic said closure; and means operative upon the opening oi said valve to move it to and retain it in a position beside its seat whereby the said passage will remain open notwithstanding subsequent seating` of the closure.

Signed at Boston, Massachusetts, this eleventh day of September, 1925.

JONATHAN C. MELOON.

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