Dry adapter for fire-extinguishing sprinkler systems

June 2, 1964 f. j. lee 3,135,331

DRY ADAPTER FOR FIRE-EXTINGUISHING SPRINKLER SYSTEMS

Filed Sept. 24, 1962

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BY /3T7~O/e/VrYS

3,135,331

Patented June 2, 1964

United States Patent Office «ίρ a length of pipe having pipe threads 4 at its extremity.

The casing 3 may extend downwardly from a fitting 2 through a wall 5 into a region wherein the temperature may drop below the freezing point of water. Alternatively, the casing 3 may extend horizontally through a wall, as shown in FIGURES 2 and 3.

The extended end of the casing 3 receives a reducer fitting 6 or a reducer elbow 7 which may be confidential. That is, in either case, the reducer fitting 6 or reducer elbow 7 is provided with an internally screw-threaded end so as to form a tightly sealed connection with the casing 3, and a reduced end also internally screw-threaded arranged to form a tightly sealed connection with a conventional sprinkler head 8, of the type which incorporates a fuse.

The inlet end of the casing 3 is internally screwthreaded to sealingly receive an inlet plug 9. The inlet plug is provided with an offset bore 10. The axially inner end of the bore 10 forms a seat which is closed by an inlet check valve 11 having a tapered seat 12.

The inlet check valve 11 extends inwardly from the inlet plug 9 and is provided with a cross bore which receives a mounting wire 13. The mounting wire 13 is L-shaped to form a laterally extending end which extends transversely through a screw pin 14, screw-threaded into the inlet plug 9 at one side of the bore 10.

The reducer fitting 6 or reducer elbow 7 is modified slightly by providing a flat area on one side. A screwthreaded bore is formed through the fitting and the end of the casing 3 therein, as shown in FIGURE 4. The screw-threaded bore thus formed receives an internally screw-threaded fitting 15 having a bore 16 counterbored at its inner end, and forming a valve seat which is closed by a telltale valve element 17.

The valve element 17 is provided with a head 18 sealingly engaging the bore 16,. and a stem 19 projects into the bore 16. The stem 19 is provided with a. transverse opening through which is threaded a pull wire 20, the ends of which initially extend outwardly through the fitting 15. A spring 21 is located within the screwthreaded fitting 15 and bears against the valve element 17, tending to lift the valve element from its seat.

The screw-threaded fitting 15, valve element 17, and associated parts form a telltale valve unit.

With reference again to the inlet valve 11, initially a screw-threaded stem 22 is inserted into the inlet valve 11 through the bore 10. The stem 22 is mounted within a sleeve 23, which in turn is fitted within the bore 10 and is provided with a shoulder 24. The stem 22 is provided ' with a head 25 and a spring 26 bears against the head 25. An internal shoulder 27 is provided within the sleeve 23 so as to hold the inlet valve 11 in yieldable engagement with the bore 10.

Operation of the dry adapter for fire-extinguishing, sprinkler systems is as follows:

The dry adapter structure is assembled by connecting the reducer fitting 6 or the reducing elbow 7 with the casing 3 and connecting the sprinkler head 8 therewith, and in addition inserting the assembled inlet plug unit as well as the telltale valve unit.

In the initial assembly, the inlet valve 11 is equipped with the stem 22 and sleeve 23. The inlet head of the casing 3 is then connected to a source of pressure fluid which is forced into the casing 3 through the inlet valve 11, it being understood that the stem 22 and sleever 23 fit sufficiently loose to permit flow of the pressure fluid into the casing 3.

The pressure fluid may be an inert gas or may be a liquid having a low freezing point, or may be a liquid and gas mixture. In any case, the fluid is such that it will not freeze at the temperatures to which the sprinkler head 8 may be subjected.

135 331

DRY ADAPTER FOR BIRE-EXTINGUISHING SPRINKLER SYSTEMS

Flovd J. Lee, 119 N. Yale St, Fullerton, Calif.

' Filed Sept 24,1962, Ser. No. 225,696 6 Claims. (Cl. 169—17)

This invention relates to dry adapters for fire-extinguishing sprinkler systems, and included in the objects of this invention are:

First, to provide a water-free or dry adapter which is connected to a water-filled, fire-extinguishing system so as to extend from the supply lines of the system maintained above freezing temperatures into regions which may be maintained below freezing temperatures, such as refrigerated rooms or regions which are exposed to ambient freezing temperatures.

Second, to provide a dry adapter for fire-extinguishing, sprinkler systems which need not be disposed in pendent relation to the water-filled supply lines of the sprinkler system, but may extend laterally, upwardly, or in any angular direction therefrom, and may extend a short or a substantial distance from the supply lines.

Third, to provide a dry adapter of this type which, although primarily adapted to carry a single sprinkler head, may be arranged to carry several.

Fourth, to provide a dry adapter which may be filled with an inert gas at a selected pressure above supply line pressure, or may be filled or partially filled and pressurized with a liquid having a low freezing point.

Fifth, to provide a dry adapter which incorporates a telltale or bleed valve operable at a predetermined pressure above line pressure so that, in the event of leakage from the adapter to the supply line, the bleed valve will open as a warning of such leakage; and wherein, should the bleed valve or sprinkler itself leak, the pressure in the adapter will drop to cause full opening of the bleed valve, thus creating in either case a warning condition which will demand attention.

Sixth, to provide a dry adapter which, on sudden release of pressure, such as caused by collapse of the fuse assembly of the sprinkler head, ensures prompt delivery of water from the water supply system.

With the above and other objects in view, as may ₄₅appear hereinafter, reference is directed to the accompanying drawings in which:

FIGURE 1 is a fragmentary, substantially diagrammatical view illustrating one manner in which the dry adapter for fire-extinguishing, sprinkler systems may be installed, wherein the adapter and sprinkler project downwardly from a ceiling;

FIGURE 2 is a similar fragmentary, diagrammatical view, showing the adapter extending horizontally through a wall and the sprinkler depending therefrom;

FIGURE 3 is a similar fragmentary, diagrammatical view, showing the dry adapter extending horizontally and the sprinkler in an upstanding position;

FIGURE 4 is an enlarged, longitudinal, fragmentary, sectional view taken through 4—4 of FIGURE 1;

FIGURE 5 is a transverse, sectional view taken through 5—5 of FIGURE 4;

FIGURE 6 is a sectional view of the inlet plug shown in FIGURES 4 and 5, and illustrating the manner in which the inlet valve is supported during charging of the dry adapter;

FIGURE 7 is an exploded view showing the parts of the telltale valve structure.

The dry adapter for fire-extinguishing, sprinkler systems is arranged to be attached to a water supply line 1 70 by a T-fitting 2 or other conventional fitting. The dry adapter includes a casing 3 which may be formed from

3,135,331

The pressure at which the casing 3 is charged is substantially above the line pressure of the water supply system to which the dry adapter is to be attached. For example, if the line pressure is 100 pounds, the casing 3 would be pressurized to 200 pounds. During the course 5 of charging the dry adapter, the pull wire or wires 20 are held manually or by a suitable tool as to maintain the valve element 17 closed against the force of the spring 21, until the internal pressure is sufficient to maintain the valve element 17 closed. Thereafter, the pull wire 20 is ιθ clipped, as indicated in FIGURE 4, or pulled free of ths valve element 17. After the dry adapter has been pressurized, the sleeve 23 and stem 22 are removed.

The dry adapter is installed by screw-threading the upper end containing the inlet plug 9 into a water supply 15 system. Should any leak occur at any of the joints confronting the interior of the casing 3, or should the sprinkler leak or should the telltale valve element 13 leak, or should the inlet valve 11 leak back into the water supply line 1, the pressure within the casing 3 will drop 20 to the pressure at the supply line 1.

The force of the spring 21 is so calculated that it will open the telltale valve at some pressure above the line pressure. For example, in the condition given previously, the telltale valve may be designed to open at 125 pounds. 25 Once the telltale valve opens, the internal pressure will continue to drop to a point below line pressure, causing the inlet valve 11 to open. Sufficient water will flow out visually to indicate malfunctioning of the dry adapter.

If desired, the pressure fluid may include a liquid con- 39 taining a dye to make more apparent any flow through the telltale valve.

In the event of a fire, the fuse, which normally holds the sprinkler closed, gives way so that the sprinkler opens. The pressure in the casing 3 rapidly drops so that the inlet 35 valve 11 quickly opens and allows the water to flow to and through the sprinkler. At this time the telltale valve may open, but the dimensions of the bore through the telltale valve are such that the amount of water lost through the telltale valve in no way interferes with the 40 functioning of the sprinkler.

While a particular embodiment of this invention has been shown and described, it is not intended to limit the same to the exact details of the construction set forth, and it embraces such changes, modifications, and equivalents of the parts and their formation and arrangement as come 45 within the purview of the appended claims.