Elastomeric pipe coupling gaskets that are commonly used with ferrous pipe couplings are lubricated so that they are not damaged during installation. Various types of oils and/or greases are used depending upon the gasket, pipe, fitting and coupling materials involved. However, such lubrication is usually supplied in a separate container and then manually applied to the gasket just prior to installation. This keeps the lubricant fresh and prevents the collection of dirt and debris on the lubricant coating prior to use of the gasket. However, it makes for a time-consuming and messy installation process.
In one aspect, the invention is a lubricated ferrous pipe coupling gasket comprising a generally tubular, one-piece, elastomeric member with first and second axial open ends, the member being formed by a circumferential wall and at least a pair of circumferential flanges, each flange extending at least generally radially inwardly at a separate one of the first and second axial open ends of the member, the circumferential wall and the pair of circumferential flanges forming at least one circumferential channel on an inner circumferential side of the member; and a coating of dry powder lubricant on at least the inner circumferential side of the member.
In another aspect, the invention is a ferrous pipe coupling comprising a ferrous collar having an outer, axially extending, axially split circumferential wall with at least one pair of adjoining circumferential ends at the split; at least one fastener releasably securing together the at least one pair of adjoining, circumferential ends of the collar; a gasket in the form of a generally tubular, one-piece, elastomeric member positioned in the collar and having an inner circumferential side exposed in the collar; and a coating of dry powder lubricant on at least the exposed, inner circumferential side of the elastomeric member.
In yet another aspect, the invention is a ferrous piping system comprising a plurality of ferrous piping components; and at least one ferrous pipe coupling mechanically and fluidly joining together ends of a pair of the piping components at a joint. The ferrous pipe coupling includes a ferrous collar having an outer, axially extending and axially split, circumferential wall and at least one pair of adjoining circumferential ends at the split, a gasket in the form of a generally tubular, one-piece elastomeric member having an inner circumferential side sealingly mounted on the ends of the pair of piping elements and surrounded by the collar; a coating of dry powder lubricant at least between the inner circumferential side of the gasket and the ends of the pair of piping components, and at least one fastener releasably securing together the pair of adjoining, circumferential ends of the collar together so as to compress the collar on the gasket and the gasket on the ends of the pair of piping components.
The foregoing summary, as well as the following detailed description of preferred embodiments of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown.
In the drawings:
Like reference numerals are used to identify the same elements to various drawings.
The system includes a plurality of piping components 11-17, which, for the most part, are lengths of pipe, couplings and fittings which have fluid passages therethrough. System 10 is configured in particular for water distribution as part of a fire sprinkler system. A one-way valve 11 is coupled with a potable water supply represented by a potable water supply pipe 9 and is arranged to supply water in only one direction from the supply pipe 9 to the piping system 10. The piping system 10 utilizing the present invention is a ferrous system utilizing lengths of iron or steel pipe and appropriate iron or steel fittings, couplings and other components for use with those pipes.
The portion of the piping system 10 depicted includes different piping components typically found in a fire sprinkler system. Elements 12 through 14 are lengths of straight pipe. Element 15 is a Tee fitting. Elements 16 are preferably identical, ferrous, split ring pipe couplings. Element 17 is a drop, a length of pipe of reduced diameter in comparison to pipe lengths 12 through 14. Finally, element 18 is an automatic fire sprinkler of conventional construction. The term “piping components” includes pipe lengths, valves, fittings and like fluid passage elements having one or more open tubular ends, which can be joined together by appropriate couplings or the like, forming joints between adjoining components, as well as plugs used in such systems.
The coupling 16 depicted in
Depending upon the nature of the coupling 16, the joint 19 can be rigid or flexible. A typical flexible joint is depicted in cross-section in
Gasket 30 is preferably a generally tubular, one-piece, elastomeric member including a circumferential wall 32 and a pair of circumferential flanges 33 and 34 located generally at first and second open axial ends 35, 36, respectively, of the circumferential wall 32 and of the gasket 30. Flanges 33 and 34 each extend at least generally radially inwardly. The circumferential wall 32 and the pair of flanges 33 and 34 also form a circumferential channel 38 on an inner circumferential side of the gasket 30. The gasket 30 may be formed from any of a variety of suitable elastomeric, preferably polymeric materials. Suggestedly, the polymer is a nitrile or an ethylene, propylene, diene monomer (“EPDM”). One-piece gasket 30 can be molded in a seamless, one-piece, continuous ring or extruded and spliced by bonding into a seamed, one-piece, continuous ring, for example, with the use of a suitable adhesive or solvent.
In use, the gasket 30 is stretched over the end 14a or 15a of one of the piping components 14, 15 and then over the other end as the ends 14a, 15a of the two components are brought together. The split ring ferrous collar 20 is then extended over and around the gasket 30 and the ends 14a, 15a of the components 14, 15 being joined. The stretched gasket 30 forms seals with both ends 14a, 15a. In order to prevent subsequent leakage, it is important that the circumferential inner side (i.e., the inner faces of the flange portions 33, 34) of the gasket 30 not be scraped or cut when being mounted on the ends 14a, 15a of the piping components. Otherwise, the gasket 30 may leak through the damaged area. For that reason, such gaskets are typically coated with an oily liquid or greasy solid material so as to be more easily and safely slipped over the adjoining ends of the piping components. However, according to the present invention, instead of using a wet liquid or greasy solid, the gasket 30 or at least the inner circumferential side of the gasket 30, which is exposed to and which directly contacts the ends 14a, 15a of the joined piping components 14, 15, is covered with a coating of dry cornstarch powder. The surface coating of cornstarch powder is indicated by shading at 40 in
While dry, powdered cornstarch is preferred, other dry, powdered organic starches such as rice starch and potato starch might alternatively be used. In addition, a powder predominantly or essentially composed of talc, i.e. magnesium silicate hydroxide (Mg3Si4O10(OH)2), which is the primary ingredient of conventional talcum powder, or that powder itself might be used as a dry lubricant. Corn, rice and potato starches, being natural ingredients derived from crops, can, with other similar naturally derived starches, be referred to generically as organic starch powder. The lubricant can include as a primary component, one of the aforementioned individual materials in combination with lesser amount(s) of the other(s).
While at least two forms of split ring, ferrous collar couplings have been disclosed, those of ordinary skill in the art will appreciate powdered cornstarch can be used on other ferrous collar coupling gaskets for use on grooved ferrous piping components as well as on other iron and steel piping components. While the split ring, ferrous collars 20, 120 and 220 and 320 described each have two ring segments, it will be appreciated that three or more segments can be employed and may be necessary in larger sizes. The segments may be identical or simply matingly symmetric for simple assembly and mounting. Similarly, in some cases, a one-piece collar of spring steel or other metal having only one pair of adjoining ends held together with a threaded fastener or a latching member might be used with a prelubricated gasket. It further will be appreciated that the present invention can be used with tubular gaskets of other configurations such as gaskets without an inner circumferential channel or distinct flanges. It will further be appreciated that while the intended use of a cornstarch lubricated polymer gasket is in fire protection systems, including automatic and deluge sprinkler piping systems, such lubricated gaskets can be installed in piping systems for other uses. Suggestedly, they are used in piping systems that are isolated from potable water supplies by suitable means such as one-way valves or in water supply systems not coupled with potable water supplies. These include various irrigation, cooling, heating and drainage systems, as well as certain other agricultural or commercial hydraulic and/or pneumatic systems.
It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.
This application is a Continuation Application of Ser. No. 09/965,983, filed Sep. 28, 2001, which is incorporated by reference in its entirety.
Number | Date | Country | |
---|---|---|---|
Parent | 09965983 | Sep 2001 | US |
Child | 12189700 | US |