FIRE PROTECTION SPRINKLER WITH A PUSH-IN CONNECTION

Abstract

A fire protection sprinkler with a push-in connection includes a sprinkler body having an input orifice for receiving fluid and an output orifice for outputting the fluid, the body having a push-in connection at the input end and a base portion. The push-in connection is adapted to be connected to a pipe fitting by insertion and has a plurality of recesses, a first recess having a first gasket, a second recess having a second gasket, and a third recess having a retaining clip. A frangible element is held in place by a set screw and a stopper. The frangible element is designed to fail at a predetermined temperature to release the stopper. A deflector is positioned on the base portion and configured to direct the output fluid toward the output end, upon activation of the sprinkler by failure of the frangible element at the predetermined temperature.

Claims

1. A fire protection sprinkler with a push-in connection comprising: a sprinkler body having an input orifice at an input end of the sprinkler for receiving fluid and an output orifice at an output end for outputting the fluid, the body having a push-in connection portion at the input end and an extended portion extending between the push-in connection portion and the output end, the push-in connection portion being adapted to be connected to a pipe fitting by insertion and having a plurality of recesses, a first recess having a first gasket therein, a second recess having a second gasket therein, and a third recess having a retaining clip therein; a pair of frame arms extending from the input end and meeting at a base portion positioned in axial alignment with the output orifice, wherein the frame arms are integrally formed with the body; a frangible element held in place on its lower end by a set screw and on its upper end by a stopper, the set screw being attached to the base portion, the frangible element being designed to fail at a predetermined temperature in order to release the stopper; and a deflector positioned on the base portion and configured to direct the fluid output from the output orifice substantially in a direction toward the output end, upon activation of the sprinkler by failure of the frangible element at the predetermined temperature.

2. The fire protection sprinkler with a push-in connection according to claim 1, wherein the first recess with the first gasket therein, the second recess with the second gasket, and the third recess with the retaining clip therein are in a stacked arrangement, with the third recess with the retaining clip therein being nearest to the frame arms.

3. The fire protection sprinkler with a push-in connection according to claim 1, wherein the first recess with the first gasket therein, the second recess with the second gasket, and the third recess with the retaining clip therein are in a stacked arrangement, with the first recess with the first gasket therein being nearest to the input end.

4. The sprinkler with a push-in connection according to claim 1, wherein the retaining clip is a spring mechanism so that the diameter of the retaining clip is reduced when the sprinkler with the push-in connection is inserted into the pipe fitting.

5. The sprinkler with a push-in connection according to claim 3, wherein the retaining clip maintains pressure against the pipe fitting when the sprinkler is installed to the pipe fitting.

6. The sprinkler with a push-in connection according to claim 1, wherein, to provide a positive connection between the retaining clip and the pipe fitting, the pipe fitting has a circumferential groove in its inner bore so that the retaining clip is located at least partially within both the third recess in the sprinkler and the circumferential groove in the pipe fitting when the sprinkler is installed.

7. The sprinkler with a push-in connection according to claim 6, wherein the retaining clip temporarily deforms while the sprinkler is inserted into the pipe fitting, and, when the sprinkler is fully inserted, is then retained within both the third recess in the sprinkler and the circumferential groove in the pipe fitting.

8. The sprinkler with a push-in connection according to claim 1, wherein the sprinkler is removed from the pipe fitting by compressing both ends of the retaining clip so that the retaining clip is less than the diameter of the internal bore of the pipe fitting allowing the sprinkler to be readily pulled from the pipe fitting.

9. The sprinkler with a push-in connection according to claim 8, wherein the sprinkler may be removed from the pipe fitting for inspection, testing, or replacement of the sprinkler.

10. The sprinkler with a push-in connection according to claim 1, wherein the first gasket and the second gasket are each O-ring seals to provide redundancy and to reduce the potential for leakage when the sprinkler is installed in the pipe fitting.

11. The sprinkler with a push-in connection according to claim 10, wherein the O-ring seals are selected from synthetic rubbers and thermoplastics, depending on desired chemical compatibility, application temperature, sealing pressure, and lubrication requirements.

12. The sprinkler with a push-in connection according to claim 1, wherein the retaining clip has a round cross section.

13. The sprinkler with a push-in connection according to claim 12, wherein the retaining clip has a diameter in the range of 0.0625 inch to 0.25 inch.

14. The sprinkler with a push-in connection according to claim 13, wherein the retaining clip has a diameter of 0.12 inch.

15. The sprinkler with a push-in connection according to claim 1, wherein the retaining clip is selected to act as a spring and to have desired corrosion resistance.

16. The sprinkler with a push-in connection according to claim 15, wherein the retaining clip is made of spring wire selected from the group consisting of stainless steel, music wire, hard drawn, oil tempered, brass, and nickel alloy.

17. The sprinkler with a push-in connection according to claim 1, wherein the retaining clip has an outer semi-circular shape of at least fifty percent, but not more than ninety percent, of a perimeter of a circle.

18. The sprinkler with a push-in connection according to claim 1, wherein the retaining clip has one of a triangular, rectangular, pentagonal, and octagonal shape.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0048] FIG. 1 is an elevational view, partly in section, of a conventional upright fire protection sprinkler mounted on a supply conduit (shown in cross section) with a threaded connection.

[0049] FIG. 2 is an elevational view of a conventional enhanced protection extended coverage pendent sprinkler having threads for connection to a supply conduit.

[0050] FIG. 3 is a plan view of a deflector showing a surface facing away from an outlet orifice in the sprinkler shown in FIG. 2.

[0051] FIG. 4 is a sectional, elevational view of the deflector shown in FIG. 3, taken along line 4-4 in FIG. 3, in the plane of the frame arms.

[0052] FIG. 5 is a perspective view of the deflector shown in FIGS. 3 and 4 showing the surface facing toward the outlet orifice.

[0053] FIG. 6 is a perspective view showing a fire protection sprinkler with a push-in connection of our invention.

[0054] FIG. 7A is an elevational view showing the fire protection sprinkler with a push-in connection of our invention in an assembled (i.e., installed) state.

[0055] FIG. 7B is an elevational view showing the fire protection sprinkler with a push-in connection of our invention prior to being installed.

[0056] FIG. 8 is an exploded view showing a fire protection sprinkler with a push-in connection of our invention.

[0057] FIG. 9 is an elevational, cross-sectional view taken along line 9-9 shown in FIG. 7A of a fire protection sprinkler with a push-in connection of our invention in an assembled (i.e., installed) state.

[0058] FIG. 10 is a partial, elevational, cross-sectional view taken along line 10-10 shown in FIG. 7A of a fire protection sprinkler with a push-in connection of our invention.

[0059] FIG. 11 shows a perspective view of an O-ring seal for use with a fire protection sprinkler with a push-in connection of our invention.

[0060] FIG. 12 is a plan view of a retainer clip for use with a fire protection sprinkler with a push-in connection of our invention.

[0061] FIG. 13 is an elevational view of a retainer clip that may be used with a fire protection sprinkler with a push-in connection of our invention.

DESCRIPTION OF THE EMBODIMENTS

[0062] Our invention relates to a fire protection sprinkler with a push-in connection that includes a sprinkler body having an input orifice at an input end of the sprinkler for receiving fluid and an output orifice at an output end for outputting the fluid, the body having a push-in connection portion at the input end and an extended portion extending between the push-in connection portion and the output end, the push-in connection portion being adapted to be connected to a pipe fitting by insertion and having a plurality of recesses, a first recess having a first gasket therein, a second recess having a second gasket therein, and a third recess having a retaining clip therein, a pair of frame arms extending from the input end and meeting at a base portion positioned in axial alignment with the output orifice, wherein the frame arms are integrally formed with the body, a frangible element held in place on its lower end by a set screw and on its upper end by a stopper, the set screw being attached to the base portion, the frangible element being designed to fail at a predetermined temperature in order to release the stopper, and a deflector positioned on the base portion and configured to direct the fluid output from the output orifice substantially in a direction toward the output end, upon activation of the sprinkler by failure of the frangible element at the predetermined temperature.

[0063] FIG. 6 is a perspective view showing a fire protection sprinkler with a push-in connection 600 of our invention. FIG. 6 shows housing 620 of our sprinkler with a push-in connection 600 inserted into (i.e., installed in) pipe outlet 603. The sprinkler with a push-in connection 600 is held in place by retaining clip 635, as will be discussed in more detail below. The sprinkler includes frame arms 640 extending to base portion 645. The sprinkler also includes a frangible element 650 that is held in place by a set screw 646. The sprinkler further includes a deflector 625 extending from the base portion 645. Deflector 625 includes upper surface 610 and peripheral edges 601. The deflector 625 may be one such as discussed above with respect to FIGS. 3 to 5. As noted above with reference to FIGS. 3 to 5, deflector 625 can be a circular disk having a number of slots of varying length and orientation arrayed around its periphery. The deflector 625 is formed of metal, such as, for example, phosphor bronze.

[0064] FIG. 7A is an elevational view showing the fire protection sprinkler with a push-in connection 700 of our invention in an assembled (i.e., installed) state. In more detail, FIG. 7A shows housing 720 of our sprinkler with a push-in connection 700 inserted into (i.e., installed in) pipe outlet 703. The sprinkler with a push-in connection 700 is held in place by retaining clip 735, as will be discussed in more detail below. The sprinkler includes frame arms 740 extending to base portion 745. The sprinkler also includes a frangible element 750 that is held in place on its lower end by a set screw 746 and on its upper end by connector 752. The sprinkler also includes a deflector 725 extending from the base portion 745. Deflector 725 includes peripheral edges 701. The deflector may be one such as discussed above with respect to FIGS. 3 to 5. As noted above with reference to FIGS. 3 to 5, deflector 725 can be a circular disk having a number of slots of varying length and orientation arrayed around its periphery. The deflector 725 is formed of metal, such as, for example, phosphor bronze.

[0065] FIG. 7B is an elevational view showing the fire protection sprinkler with a push-in connection 700 of our invention prior to being inserted into (i.e., installed in) a pipe outlet. Notably, FIG. 7B shows a first gasket or O-ring seal 765 and a second gasket or O-ring seal 775 mounted in corresponding recesses as will be discussed in more detail below. As noted above, the sprinkler with a push-in connection 700 is held in place by retaining clip 735, as also will be discussed in more detail below. The sprinkler includes frame arms 740 extending to base portion 745. The sprinkler also includes a frangible element 750 that is held in place on its lower end by a set screw 746 and on its upper end by connector 752. The sprinkler further includes a deflector 725 extending from the base portion 745. Deflector 725 includes peripheral edges 701. The deflector may be one such as discussed above with respect to FIGS. 3 to 5. As noted above with reference to FIGS. 3 to 5, deflector 725 can be a circular disk having a number of slots of varying length and orientation arrayed around its periphery. The deflector 725 is formed of metal, such as, for example, phosphor bronze.

[0066] FIG. 8 is an exploded view showing a fire protection sprinkler with a push-in connection 800 of our invention prior to being inserted into (i.e., installed in) pipe outlet 803. Pipe outlet 803 has a notch 837 into which the retaining clip 835 will be engaged. FIG. 8 shows first gasket or O-ring seal 865 and second gasket or O-ring seal 875 to be mounted in corresponding recesses 860 and 870. Similarly, retaining clip 835 will be mounted in corresponding recess 830 as will be discussed in more detail below. The sprinkler includes frame arms 842 extending to base portion 845. The sprinkler also includes a frangible element 850 that is held in place on its lower end by a set screw 846 and on its upper end by connector 852. The connector 852 connects with a sealing cap or stopper 840 having a washer or other disk spacer 844 in between. The sprinkler also includes a deflector 825 that will extend from the base portion 845. Deflector 825 includes peripheral edges 801. The deflector may be one such as discussed above with respect to FIGS. 3 to 5. As noted above with reference to FIGS. 3 to 5, deflector 825 can be a circular disk having a number of slots of varying length and orientation arrayed around its periphery. The deflector 825 is formed of metal, such as, for example, phosphor bronze.

[0067] Accordingly, the fire protection sprinkler with a push-in connection 800 of our invention comprises one or more gaskets or O-ring seals 865 and 875 located in one or more corresponding recesses 860 and 870. Preferably, more than one gasket or O-ring seal is used to provide redundancy and to reduce (or to eliminate) the potential for leakage. An advantage of our mechanism is that all seals are located on the sprinkler, not on the pipe outlet. This allows the pipe outlet (not shown in FIG. 8), prior to installation of the fire protection sprinkler with a push-in connection 800, to be attached to the pipe using a welded connection, without concern for the high temperatures from the welding process damaging the seal.

[0068] The fire protection sprinkler with a push-in connection 800 of our invention further comprises retaining clip 835 used to retain the sprinkler in the pipe outlet. The retaining clip 835 is retained within the groove 837 in the fire protection sprinkler with a push-in connection 800 of our invention. The retaining clip 835 temporarily deforms while the fire protection sprinkler with a push-in connection 800 is inserted into the pipe outlet and, when the fire protection sprinkler with a push-in connection 800 is fully inserted, is then retained by both the groove 837 in the fire protection sprinkler with a push-in connection 800 and a corresponding groove in the pipe outlet. The groove 837 in the sprinkler fire protection sprinkler with a push-in connection 800 includes a retaining surface designed to press the retaining clip 835 into the groove in the pipe outlet when elevated pressure in the pipe presses the sprinkler fire protection sprinkler with a push-in connection 800 in a direction away from the pipe outlet. The force from the retaining surface against the clip when water pressure is applied to the inlet further prevents the fire protection sprinkler with a push-in connection 800 from being removed from the pipe outlet when there is pressurized fluid in the pipe.

[0069] The retaining clip 835 has two ends (shown in FIG. 8, but not enumerated, but see elements 1210 and 1220 shown in FIG. 12) that are not retained within the groove 837 in the fire protection sprinkler with a push-in connection 800 or the corresponding groove in the pipe outlet. When the inlet of the fire protection sprinkler with a push-in connection 800 is not pressurized, the two ends of the retaining clip 835 may be used to reduce the radius of the retaining clip 835 so that the retaining clip 835 can be retained within the groove 837 in the fire protection sprinkler with a push-in connection 800, but not the corresponding groove in the pipe outlet, thereby allowing the fire protection sprinkler with a push-in connection 800 to be removed from the pipe outlet for desired reasons, such as inspection, testing, or replacement.

[0070] The fire protection sprinkler with a push-in connection 800 thereby may be installed in a pipe outlet by simply pressing the fire protection sprinkler with a push-in connection 800 into the pipe outlet. Pressing the fire protection sprinkler with a push-in connection 800 into the pipe outlet will cause the retaining clip 835 to retract into the groove 837 to allow the fire protection sprinkler with a push-in connection 800 to be inserted into the pipe outlet. When the fire protection sprinkler with a push-in connection 800 is inserted into the pipe outlet so that the groove 837 in the fire protection sprinkler with a push-in connection 800 is adjacent to the corresponding groove in the pipe outlet, the retaining clip 835 will elastically expand into the groove in the pipe outlet, releasably retaining the fire protection sprinkler with a push-in connection 800 in the pipe outlet.

[0071] FIG. 9 is an elevational, cross-sectional view taken along line 9-9 shown in FIG. 7A of a fire protection sprinkler with a push-in connection 900 of our invention in an assembled (i.e., installed) state in pipe outlet 903. Pipe outlet 903 has a notch 937 into which the retaining clip 935 is engaged. FIG. 9 shows first gasket or O-ring seal 965 and second gasket or O-ring seal 975 to be mounted in corresponding recesses. Similarly, retaining clip 935 is mounted in recess 937. The sprinkler includes frame arms (not shown in this view) extending to base portion 945. The sprinkler also includes a frangible element 950 that is held in place on its lower end by a set screw 946 and on its upper end by a connector (not shown) that connects with stopper 942. The sprinkler also includes a deflector 925 that extends from the base portion 945. Deflector 925 includes upper surface 910. As noted above with reference to FIGS. 3 to 5, deflector 925 can be a circular disk having a number of slots of varying length and orientation arrayed around its periphery. The deflector 925 is formed of metal, such as, for example, phosphor bronze.

[0072] FIG. 10 is a partial, elevational, cross-sectional view taken along line 10-10 shown in FIG. 7A of a fire protection sprinkler with a push-in connection 1000 of our invention in an assembled (i.e., installed) state in pipe outlet 1003. Pipe outlet 1003 has a notch 1037 into which the retaining clip 1035 is engaged. FIG. 10 shows first gasket or O-ring seal 1065 and second gasket or O-ring seal 1075 to be mounted in corresponding recesses. Similarly, retaining clip 1035 is mounted in recess 1037. For ease of discussion, FIG. 10 does not show the sprinkler portion.

[0073] FIG. 11 shows a perspective view of an O-ring seal 1100 for use with a fire protection sprinkler with a push-in connection of our invention. FIG. 11 includes reference number 1110, showing an outer peripheral edge, and reference number 1115, showing an inner peripheral edge. As discussed in detail above, our invention uses two O-ring seals 1100 to provide redundancy and to reduce (or even to eliminate) the potential for leakage.

[0074] Generally speaking, an O-ring, also known as a packing or a toric joint, is a mechanical gasket in the shape of a torus. It is a loop of elastomer with a round cross section, designed to be seated in a groove and compressed during assembly between two or more parts, creating a seal at the interface.

[0075] The O-ring may be used in static applications or in dynamic applications, where there is relative motion between the parts and the O-ring. Static applications of O-rings may include fluid or gas sealing applications in which: (1) the O-ring is compressed resulting in zero clearance, (2) the O-ring material is a vulcanized solid such that it is impermeable to the fluid or gas, and (3) the O-ring material is resistant to degradation by the fluid or gas.

[0076] O-rings are one of the most common seals used in machine design because they are inexpensive, easy to make, reliable, and have simple mounting requirements. They have been tested to seal up to 5000 psi (35 megapascals) of pressure. The maximum recommended pressure of an O-ring seal depends on the seal hardness and gland clearance.

[0077] O-rings are available in various metric and inch standard sizes. Sizes are specified by the inside diameter and the cross-sectional diameter (thickness). In the U.S., the most common standard inch sizes are per SAE AS568C specification (e.g., AS568-214). ISO 3601-1:2012 contains the most commonly used standard sizes, both inch and metric, worldwide. The UK also has standards sizes known as British Standard (BS) sizes, typically, ranging from BS001 to BS932. Several other size specifications also exist.

[0078] Successful O-ring joint design requires a rigid mechanical mounting that applies a predictable deformation to the O-ring. This introduces a calculated mechanical stress at the O-ring contacting surfaces. As long as the pressure of the fluid being contained does not exceed the contact stress of the O-ring, leaking cannot occur. The pressure of the contained fluid transfers through the essentially incompressible O-ring material, and the contact stress rises with increasing pressure. For this reason, an O-ring can easily seal high pressure as long as it does not fail mechanically. The most common failure is extrusion through the mating parts.

[0079] The seal is designed to have a point contact between the O-ring and sealing faces. This allows a high local stress, able to contain high pressure, without exceeding the yield stress of the O-ring body. The flexible nature of O-ring materials accommodates imperfections in the mounting parts. But, it is still important to maintain good surface finish of those mating parts, especially at low temperatures where the seal rubber reaches its glass transition temperature and becomes increasingly crystalline. Surface finish is also especially important in dynamic applications. A surface finish that is too rough will abrade the surface of the O-ring, and a surface that is too smooth will not allow the seal to be adequately lubricated by a fluid film.

[0080] O-ring selection is based on chemical compatibility, application temperature, sealing pressure, lubrication requirements, durometer, size, and cost.

[0081] O-rings are typically made from the following materials:

[0082] (A) Synthetic rubbers or thermosets [0083] Butadiene rubber (BR) [0084] Butyl rubber (IIR) [0085] Chlorosulfonated polyethylene (CSM) [0086] Epichlorohydrin rubber (ECH, ECO) [0087] Ethylene propylene diene monomer (EPDM): good resistance to hot water and steam, detergents, caustic potash solutions, sodium hydroxide solutions, silicone oils and greases, many polar solvents and many diluted acids and chemicals. Special formulations are excellent for use with glycol-based brake fluids. Unsuitable for use with mineral oil products: lubricants, oils, or fuels. Peroxide-cured compounds are suitable for higher temperatures. [0088] Ethylene propylene rubber (EPR) [0089] Fluoroelastomer (FKM): noted for their very high resistance to heat and a wide variety of chemicals. Other key benefits include excellent resistance to aging and ozone, very low gas permeability and the fact that the materials are self-extinguishing. Standard FKM materials have excellent resistance to mineral oils and greases, aliphatic, aromatic and chlorinated hydrocarbons, fuels, non-flammable hydraulic fluids (HFD) and many organic solvents and chemicals. Generally, not resistant to hot water, steam, polar solvents, glycol-based brake fluids and low molecular weight organic acids. In addition to the standard FKM materials, a number of specialty materials with different monomer compositions and fluorine content (65% to 71%) are available that offer improved chemical or temperature resistance and/or better low temperature performance. [0090] Nitrile rubber (NBR, HNBR, HSN, Buna-N): a common material for O-rings because of its good mechanical properties, its resistance to lubricants and greases, and its relatively low cost. The physical and chemical resistance properties of NBR materials are determined by the acrylonitrile (ACN) content of the base polymer: low content ensures good flexibility at low temperatures, but offers limited resistance to oils and fuels. As the ACN content increases, the low temperature flexibility reduces and the resistance to oils and fuels improves. Physical and chemical resistance properties of NBR materials are also affected by the cure system of the polymer. Peroxide-cured materials have improved physical properties, chemical resistance and thermal properties, as compared to sulfur-donor-cured materials. Standard grades of NBR are typically resistant to mineral oil-based lubricants and greases, many grades of hydraulic fluids, aliphatic hydrocarbons, silicone oils and greases and water to about 80° C. NBR is generally not resistant to aromatic and chlorinated hydrocarbons, fuels with a high aromatic content, polar solvents, glycol-based brake fluids and non-flammable hydraulic fluids (HFD). NBR also has low resistance to ozone, weathering and aging. HNBR has considerable improvement of the resistance to heat, ozone and aging, and gives it good mechanical properties. [0091] Perfluoroelastomer (FFKM) [0092] Polyacrylate rubber (ACM) [0093] Polychloroprene (neoprene) (CR) [0094] Polyisoprene (IR) [0095] Polysulfide rubber (PSR) [0096] Polytetrafluoroethylene (PTFE) [0097] Sanifluor (FEPM) [0098] Silicone rubber (SiR): noted for their ability to be used over a wide temperature range and for excellent resistance to ozone, weathering and aging. Compared with most other sealing elastomers, the physical properties of silicones are poor. Generally, silicone materials are physiologically harmless so they are commonly used by the food and drug industries. Standard silicones are resistant to water (to 100° C.), aliphatic engine and transmission oils and animal and plant oils and fats. Silicones are generally not resistant to fuels, aromatic mineral oils, steam (short term to 120° C. is possible), silicone oils and greases, acids or alkalis. Fluorosilicone elastomers are far more resistant to oils and fuels. The temperature range of applications is somewhat more restricted. [0099] Styrene-butadiene rubber (SBR); and

[0100] (B) Thermoplastics: [0101] Thermoplastic elastomer (TPE) styrenics [0102] Thermoplastic polyolefin (TPO) LDPE, HDPE, LLDPE, ULDPE [0103] Thermoplastic polyurethane (TPU) polyether, polyester: Polyurethanes differ from classic elastomers in that they have much better mechanical properties. In particular they have a high resistance to abrasion, wear and extrusion, a high tensile strength and excellent tear resistance. Polyurethanes are generally resistant to aging and ozone, mineral oils and greases, silicone oils and greases, nonflammable hydraulic fluids HFA & HFB, water up to 50° C. and aliphatic hydrocarbons. [0104] Thermoplastic etheresterelastomers (TEEEs) copolyesters [0105] Thermoplastic polyamide (PEBA) Polyamides [0106] Melt Processible Rubber (MPR) [0107] Thermoplastic Vulcanizate (TPV)

[0108] (C) Chemical Compatibility [0109] Air, 200-300° F.—Silicone [0110] Water—EPDM

[0111] FIG. 12 is a plan view of a retaining clip 1200 for use with a fire protection sprinkler with a push-in connection of our invention. The retaining clip 1200 has an outer semi-circular shape, having an arcuate segment 1204, and ends 1210 and 1220. (We have discussed the operation of the retaining clip 1200 in detail above. Accordingly, we will not repeat that discussion here.)

[0112] The retaining clip 1200 may have various cross-sectional shapes. We prefer that the retaining clip 1200 be circular in cross section. We note, however, that retaining clip 1200 may have other cross-sectional shapes as desired, such as triangular, rectangular, pentagonal, octangular, and the like. Generally speaking, retaining clip 1200 is made of spring wire and is circular in cross section, having a diameter in the range of 0.0625 inch to 0.25 inch, and, likely, will have a diameter of about 0.12 inch. Retaining clip 1200 will have these general dimensions, even if having other cross-sectional configurations.

[0113] The five most common spring wire material options are: [0114] Stainless Steel—Cold drawn, general-purpose wire. Features include corrosion and heat resistance. [0115] Music Wire—Highest quality cold drawn, high carbon wire. High strength and features a good surface finish. [0116] Hard Drawn MB—Cold drawn wire for average stress applications. Medium strength and low cost. [0117] Oil Tempered—Wire is cold drawn, and heat treated before fabrication. Good general-purpose spring wire for torsion springs. [0118] Brass—Generally not used as commonly due to cost. Tends to tarnish and change color over time. Features good corrosion and water resistance. [0119] Nickel alloy. Generally speaking, the material for the retainer clip 1200 would be selected to act as a spring and have good corrosion resistance. Nickel alloy (as well as the other materials mentioned above) provides these attributes.

[0120] FIG. 13 is an elevational view of a retaining clip showing arcuate (i.e., semi-cylindrical) portion 1304 for use with a fire protection sprinkler with a push-in connection of our invention. Specifically, arcuate portion 1304 has a semi-circular shape of at least fifty percent, but not more than ninety percent of a perimeter of a circle.

[0121] While the present invention has been described with respect to what are, at present, considered to be the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, the invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.