BACKGROUND

Field of the Invention

This invention relates generally to fire prevention sprinklers, and more particularly to dry sprinklers.

Fire prevention sprinklers of the type known as dry sprinklers are used in areas that are exposed to freezing conditions, such as in freezers or unconditioned areas in and around buildings that may experience freezing conditions. In some sprinkler systems using dry sprinklers, supply conduits configured to supply a fluid are provided in a space that is not subject to freezing. A dry sprinkler is attached to the supply conduit and extends into a space that is subject to freezing.

FIG. 1shows a conventional dry sprinkler in a non-actuated state, andFIG. 2shows the same dry sprinkler in an actuated state. As shown inFIGS. 1 and 2, this conventional dry sprinkler includes an outer casing tube1, an inner tube2located inside the outer casing tube1and having a proximal opening4, an intermediate opening6, a distal opening7, and a sprinkler deflector11at a distal end. The conventional dry sprinkler also has an inlet fitting3for connecting to a supply conduit (not shown), and a sealing washer5, positioned in a seat in the inlet fitting3, for creating a seal between the dry sprinkler and the supply conduit when the dry sprinkler is in an unactuated state. Moreover, the conventional dry sprinkler typically includes, at its distal end, an operating element, including an orifice adapter8, a plug9, and a temperature-sensitive element10.

During actuation of the conventional dry sprinkler, the operating element responds to a high-temperature condition sufficient to fracture the temperature-sensitive element10, releasing the temperature-sensitive element10from the sprinkler, permitting the plug9to be expelled from the sprinkler and the distal end of the inner tube2to move toward the sprinkler deflector11. Movement of the inner tube2towards the sprinkler deflector11releases the sealing washer5from the seat, allowing the fluid in the supply conduit to pass through the sprinkler for delivery to the space being protected by the sprinkler. The fluid flows primarily, if not totally, into the proximal opening4, through the inner tube2, and is discharged through the distal opening7and the orifice adapter8, striking the sprinkler deflector11. The sprinkler deflector11directs the fluid onto the space protected by the sprinkler in a predetermined pattern.

Since the fluid flows through the inner tube2in the conventional dry sprinkler, the inner tube2in conventional dry sprinklers typically has an outer diameter that is only slightly smaller than the inner diameter of the outer casing tube1. For example, conventional dry sprinklers are known that have an inner tube2with an outer diameter that is only approximately 0.2 inch (0.5 cm) smaller than the inner diameter of the outer casing tube1, so there is a small 0.1 inch (0.25 cm) gap, on average, between the inner tube2and the outer casing tube1.FIG. 1Ashows a cross-sectional illustration of the outer casing tube1and the inner tube2of the sprinkler shown inFIG. 1.

Also, in order to increase the flow rate of the fluid through the sprinkler at a certain supply pressure, it is typically necessary to increase the diameter of the inner tube2and, therefore, to increase the size of the whole sprinkler. When dry sprinklers are used to protect storage spaces, the flow rates required are relatively large as compared with the flow rates required to protect light hazard and ordinary hazard occupancies. The large flow rates required to protect storage spaces also require a relatively heavier construction to permit the increased flow rates at typical supply pressures. The result of these requirements is a conventional sprinkler of heavy, expensive construction, and having large fittings at the inlet end to accommodate desired large flow rates as well as the mentioned elevated pressures. The inlet fitting3, shown inFIG. 1, is an example of such a large fitting. Conventional dry sprinklers may also require special modifications in design at the distal (sprinkler deflector) end. In addition to these disadvantages, the resulting heavy sprinkler may also be difficult to install because of its bulkiness and weight.

For dry-type storage sprinklers having a K-factor (flow coefficient relating the flow rate through the sprinkler to the square root of the fluid pressure in the supply conduit) of more than 14 gpm/(psi)1/2(gpm/(psi)1/2being the largest K-factor for commercially available sprinklers), the inlet size (that is, the diameter of the orifice closed by the inlet seal assembly) has been increased to obtain relatively larger K-factors. As the inlet is made larger, however, the force that the operating element must withstand increases for the same fluid pressure in the supply conduit. As the size of the inlet orifice increases, the area of the sealing washer exposed to the fluid in the supply conduit also increases. The force on the sealing washer is the product of the pressure of fluid in the supply conduit and the area of the sealing washer exposed to fluid in the supply conduit. To maintain the sealing washer in the seat in the inlet without leaking or rupture of the sprinkler, the force on the sealing washer from the operating element must be at least equal to the force on the sealing washer from the fluid in the supply conduit. United States Underwriter's Laboratories (UL) Standard 199, Standard for Safety for Automatic Sprinklers for Fire-Protection Service, Eleventh Edition, and UL Standard 1767, Standard for Safety for Early-Suppression Fast-Response Sprinklers, Fourth Edition, both require that sprinklers withstand a pressure of 500 psig (3447.4 kPs) in the supply conduit without leaking of the sprinkler, and a pressure of 700 psig (4826.3 kPa) in the supply conduit without rupture of the sprinkler. As an example, exposing a sealing washer having a 1-inch (2.54-cm) diameter to a pressure of 700 psig (4826.3 kPa) would require the operating element to withstand a force exceeding 549 pounds (249 kg), while exposing a sealing washer having a 1¼-inch (3.175 cm) diameter to the same 700 psig (4826.3 kPa) pressure would require the operating element to withstand a force of more than 858 pounds (389 kg). Stronger operating elements are required to resist the force produced as a result of using a larger inlet orifice and a larger sealing washer. However, increasing the strength of the operating element by increasing the size and mass of the operating element reduces the sensitivity of the operating element to changes in temperature that cause operation of the sprinkler, thereby delaying sprinkler operation.

As a result, these conventional dry sprinklers typically have a maximum K-factor of 16.8 gpm/(psi)1/2. And, even with a large and heavy sprinkler, it is conventionally only possible to use such a sprinkler in a sprinkler system with a maximum spacing of 10 feet (3.05 m) between sprinklers, for a maximum area protected of 100 square feet (9.29 square meters) per sprinkler.

SUMMARY

To address the problems described above, a dry sprinkler is provided having a translating member connecting an operating element and a sealing washer, constructed such that fluid, such as water, flows around the translating member and between the translating member and a casing tube, utilizing a cross-sectional area of the casing tube, instead of being limited to flow through an inner tube.

A dry sprinkler is provided having a casing tube having an inlet at a first end, the inlet defining an inlet orifice, and an outlet at a second end, the outlet defining an outlet orifice. An inlet seal assembly is configured to operatively seal the inlet orifice when the sprinkler is in a non-actuated state, and an outlet seat assembly is configured to operatively seal the outlet orifice when the sprinkler is in the non-actuated state. In addition, a translating member extends between the inlet and the outlet through the casing tube, and (i) supports the inlet seal assembly to seal the inlet orifice, (ii) is supported by the outlet seat assembly, and (iii) is configured to axially translate from a first position, in which the translating member is supported by the outlet seat assembly and retains the inlet seal assembly in a sealed state, to a second position, in which the translating member is not supported by the outlet seat assembly and releases the inlet seal assembly, toward the outlet when the outlet seat assembly is released. The dry sprinkler has a nominal K-factor greater than 17 gpm/(psi)1/2. In addition, a difference between a cross-sectional area of the casing tube and a cross-sectional area bounded by an outer perimeter of the translating member is more than 30% of the cross-sectional area of the casing tube.

In one embodiment, the translating member is a tube. In another embodiment, the translating member is a solid rod. In another embodiment, a cross-sectional shape of the translating member is a polygon. In yet another embodiment, a cross-sectional shape of the translating member is a cross. According to another embodiment, the nominal K-factor is equal to or greater than 22.4 gpm/(psi)1/2.

In another embodiment, a dry sprinkler comprises a casing tube having an inlet at a first end, the inlet defining an inlet orifice, and an outlet at a second end, the outlet defining an outlet orifice. An inlet seal assembly is configured to operatively seal the inlet orifice when the sprinkler is in a non-actuated state, and an outlet seat assembly configured to operatively seal the outlet orifice when the sprinkler is in the non-actuated state. In addition, a translating member extends between the inlet and the outlet through the casing tube, and (i) supports the inlet seal assembly to seal the inlet orifice, (ii) is supported by the outlet seat assembly, and (iii) is configured to axially translate from a first position, in which the translating member is supported by the outlet seat assembly and retains the inlet seal assembly in a sealed state, to a second position, in which the translating member is not supported by the outlet seat assembly and releases the inlet seal assembly, toward the outlet when the outlet seat assembly is released. In this embodiment, the dry sprinkler is an extended coverage dry pendent storage sprinkler having a coverage area of greater than 10.22 square meters (110 square feet).

According to another embodiment, the coverage area is at least 13.38 square meters (144 square feet). According to yet another embodiment, the coverage area is at least 18.209 square meters (196 square feet).

In another embodiment, a dry sprinkler comprises a casing tube having an inlet at a first end, the inlet defining an inlet orifice, and an outlet at a second end, the outlet defining an outlet orifice. An inlet seal assembly is configured to operatively seal the inlet orifice when the sprinkler is in a non-actuated state, and an outlet seat assembly configured to operatively seal the outlet orifice when the sprinkler is in the non-actuated state. A translating member extends between the inlet and the outlet through the casing tube, and (i) supports the inlet seal assembly to seal the inlet orifice, (ii) is supported by the outlet seat assembly, and (iii) is configured to axially translate from a first position, in which the translating member is supported by the outlet seat assembly and retains the inlet seal assembly in a sealed state, to a second position, in which the translating member is not supported by the outlet seat assembly and releases the inlet seal assembly, toward the outlet when the outlet seat assembly is released, wherein the translating member has a cross-sectional area that occupies at least 2% of, and not more than 65% of, an internal cross-sectional area of the casing tube. In addition, the inlet orifice and the outlet orifice communicate with a volume interior of the casing tube and exterior of the translating member.

In one embodiment, the casing tube has an average outer diameter of at least 38.1 mm (1.5 inches). In another, embodiment, the casing tube has an average outer diameter of 38.1 to 63.5 mm (1.5 to 2.5 in.). In yet another embodiment, the casing tube has an average inner diameter that is at least 5.08 mm (0.2 in.) greater than an average outer diameter of the translating member.

In another embodiment, a dry sprinkler comprises a casing tube having an inlet at a first end, the inlet defining an inlet orifice and having a central axis, and an outlet at a second end, the outlet defining an outlet orifice. An inlet seal assembly is configured to seal the inlet orifice, and comprises a body having an asymmetric cap portion including a first portion on one side of a plane that contains the central axis of the inlet, and a second portion on an opposite side of the plane, wherein, with respect to a second axis that passes through and is normal to the central axis of the inlet, the first portion has a greater moment of inertia than the second portion, and a sealing washer provided on the body, the sealing washer being urged against the inlet when the sprinkler is in a non-actuated state, and urging the inlet seal assembly away from the inlet upon actuation of the sprinkler. The dry sprinkler also comprises an outlet seat assembly configured to operatively seal the outlet when the sprinkler is in the non-actuated state. A translating member extends between the inlet and the outlet through the casing tube, and (i) supports the inlet seal assembly to seal the inlet orifice, (ii) is supported by the outlet seat assembly, and (iii) is configured to axially translate from a first position, in which the translating member is supported by the outlet seat assembly and retains the inlet seal assembly in a sealed state, to a second position, in which the translating member is not supported by the outlet seat assembly and releases the inlet seal assembly toward the outlet when the outlet seat assembly is released, wherein the dry sprinkler has a nominal K-factor greater than 16.8 gpm/(psi)1/2.

In one embodiment, the first portion of the body of the inlet seal assembly has a greater mass than the second portion. In another embodiment, the body of the inlet seal assembly has a first generally planar surface supporting the sealing washer, and a second surface, the second surface being positioned at a first height from the first generally planar surface on a first side of the body relative to the central axis of the inlet, and positioned at a second height from the first generally planar surface on a second side of the body that is opposite to the first side of the body relative to the central axis of the inlet, the second height being less than the first height. In one embodiment, the second surface is generally planar and is inclined at an angle relative to the first generally planar surface. In another embodiment, the angle is greater than zero but less than 12.5°. In yet another embodiment, the angle is greater than about 15° but less than 25.5°.

In another embodiment, a dry sprinkler comprises a casing tube having an inlet at a first end, the inlet defining an inlet orifice, and a second end. An inlet seal assembly is configured to operatively seal the inlet orifice when the sprinkler is in a non-actuated state. A sprinkler head is connected to the second end of the casing tube, and comprises a deflector, and a frame supporting the deflector, and having a connector machined into the frame, the connector (i) securing the sprinkler head to the second end of the casing tube, and (ii) defining an outlet orifice facing the deflector to deliver liquid to the deflector upon actuation of the sprinkler. The dry sprinkler also comprises a translating member extending between the inlet and the outlet through the casing tube, the translating member (i) supporting the inlet seal assembly to seal the inlet orifice, and (ii) being configured to axially translate from a first position, in which the translating member retains the inlet seal assembly in a sealed state, to a second position, in which the translating member releases the inlet seal assembly. In addition, a support is provided adjacent to the outlet orifice along an axis that is perpendicular to a longitudinal axis of the translating member and supporting the translating member when the sprinkler is in the non-actuated state. The translating member is supported by the support in the first position and wherein the translating member is constructed to axially translate toward the outlet upon actuation of the sprinkler. In addition, the dry sprinkler has a nominal K-factor greater than 16.8 gpm/(psi)1/2.

In another embodiment, a dry sprinkler comprises a casing tube having an inlet at a first end, the inlet defining an inlet orifice and having a central axis, and an outlet at a second end, the outlet defining an outlet orifice. An inlet seal assembly is configured to seal the inlet orifice, and has a body having an asymmetric cap portion including a first portion on one side of a plane that contains the central axis of the inlet, and a second portion on an opposite side of the plane, wherein, with respect to a second axis that passes through and is normal to the central axis of the inlet, the first portion has a greater moment of inertia than the second portion, and a sealing washer provided on the body, the sealing washer being urged against the inlet when the sprinkler is in a non-actuated state, and urging the inlet seal assembly away from the inlet upon actuation of the sprinkler. The dry sprinkler also comprises an outlet seat assembly configured to operatively seal the outlet when the sprinkler is in the non-actuated state. In addition, a translating member extends between the inlet and the outlet through the casing tube, and (i) supports the inlet seal assembly to seal the inlet orifice, (ii) is supported by the outlet seat assembly, and (iii) is configured to axially translate from a first position, in which the translating member is supported by the outlet seat assembly and retains the inlet seal assembly in a sealed state, to a second position, in which the translating member is not supported by the outlet seat assembly and releases the inlet seal assembly. A sprinkler head is secured to the second end of the casing tube, and comprises a deflector, and a frame supporting the deflector. In this embodiment, the sprinkler head is an extended coverage sprinkler head.

In yet another embodiment, a dry sprinkler comprises a casing tube having an inlet at a first end, the inlet defining an inlet orifice and having a central axis, and an outlet at a second end, the outlet defining an outlet orifice. An inlet seal assembly is configured to seal the inlet orifice, and comprises a body having an asymmetric cap portion including a first portion on one side of a plane that contains the central axis of the inlet, and a second portion on an opposite side of the plane, wherein, with respect to a second axis that passes through and is normal to the central axis of the inlet, the first portion has a greater moment of inertia than the second portion, and a sealing washer provided on the body, the sealing washer being urged against the inlet when the sprinkler is in a non-actuated state, and urging the inlet seal assembly away from the inlet upon actuation of the sprinkler. The dry sprinkler also comprises an outlet seat assembly configured to operatively seal the outlet when the sprinkler is in the non-actuated state. In addition, a translating member extends between the inlet and the outlet through the casing tube, and (i) supports the inlet seal assembly to seal the inlet orifice, (ii) is supported by the outlet seat assembly, and (iii) is configured to axially translate from a first position, in which the translating member is supported by the outlet seat assembly and retains the inlet seal assembly in a sealed state, to a second position, in which the translating member is not supported by the outlet seat assembly and releases the inlet seal assembly. In addition, a sprinkler head is secured to the second end of the casing tube, and comprises a deflector, and a frame supporting the deflector. In this embodiment, the casing tube has an average internal cross-sectional area of at least 1161.29 sq. mm (1.8 sq. in.).

