Patent Application
20080246276
This invention relates to a penetration fitting which permits a conduit to pass through a wall of a sump, and especially, a sump used in an underground fuel storage system such as are commonly found at service stations.
Secondary containment systems have been developed for gasoline service stations in order to prevent leaking hydrocarbons from contaminating the ground around and beneath such service stations. A secondary containment system typically includes a primary pipeline in which a product such as gasoline flows from an underground storage tank to a product dispenser, and a secondary pipeline that surrounds the primary pipeline. The purpose of the secondary pipeline is to contain any fluid that may leak from a damaged primary pipeline, and prevent the fluid from contaminating the surrounding ground. The secondary pipeline is generally monitored for fluid collection so that any leak in the primary pipeline can be repaired promptly.
A typical secondary containment system also includes one or more containment boxes or sumps beneath equipment such as gasoline or diesel product dispensers. Product pipelines extend through the walls of such sumps to pipe fittings which connect the primary pipelines to the product dispensers. Such sumps are designed to contain any product which may leak from faulty fittings or pipelines. In some installations, the secondary pipelines end at the walls of such sumps. In other installations, the secondary pipelines continue through the walls of such sumps such that virtually the entire piping system up to the product dispenser includes double-walled pipe. Furthermore, in some installations, the sumps are of a double-wall construction such that the inner wall acts as a portion of the secondary containment system while the outer wall acts as a tertiary containment system. Such installations are well known and are described in patents such as U.S. Pat. No. 6,823,886 which is incorporated by reference.
Regardless of the piping configuration, penetration fittings are used to form seals between sumps and the associated pipelines to contain leakage within the sumps. However, penetration fittings can be a source of system failure. Flexible penetration fittings tend to be made of materials that cannot withstand years of exposure to damp ground on one side, and hydrocarbons on the other side. Rigid penetration fittings tend to be complicated to install in that they require numerous glued joints. Furthermore, when using rigid penetration fittings, the entire system must generally be installed in its entirety, with final connection of both primary and secondary pipelines, before the integrity of such a system can be tested. If a fault is found after installation, large portions of the system, and in some cases, virtually the entire system must be dismantled in order to locate and correct the fault.
A penetration fitting is provided for forming a sealed penetration through an aperture of a sump wall. The penetration fitting includes a flanged coupling comprising a generally rigid coupler and an integral first flange extending around a portion of the coupler. The first flange abuts a first side of the sump wall around the aperture. Opposing ends of the coupler further define first and second fittings, the second fitting adapted to extend through the aperture. A ring flange is provided that is adapted to be adhered to an outer circumferential portion of the coupler and abut a second side of the sump wall around the aperture.
In one embodiment, the first fitting is a tapered fitting for mating with a tapered secondary pipeline and the second fitting is a slip fitting for mating with a primary pipeline coaxially located within the secondary pipeline. Together, the primary and secondary pipelines define an annular space between the primary and secondary pipelines. For such an embodiment, the penetration fitting may include an optional secondary test port for external communication with the annular space and permitting the testing of the integrity of the secondary pipe system once installation is complete.
In still another embodiment, the coupler includes slip fittings on either end. For penetration fittings that include a slip fitting, the slip fitting may further include an interior adhesive channel and an adhesive injection port through which adhesive can be injected to adhere the slip fitting to the corresponding pipeline. In one embodiment, both the first and second slip fittings are adapted to mate with a secondary pipeline. In another embodiment, the first slip fitting is adapted to mate with a secondary pipeline and the second slip fitting is adapted to mate with a primary pipeline coaxially located within the secondary pipeline and defining an annular space as described above. For such an embodiment, the penetration fitting can further include an optional secondary test port for external communication with the annular space between the primary and secondary pipelines.
In another embodiment, the penetration fitting is designed for use with a double-wall sump that defines a sump wall interstice. For such an embodiment, at least one of the first and second fittings receives a secondary pipeline, and at least one interstitial port is provided for communication between the sump wall interstice and an outer wall of the secondary pipeline. This is useful for ensuring a proper seal between the penetration fitting and the double-wall sump wall. An optional interstice test port may be provided for external communication with the at least one interstitial port. This is useful for testing the integrity of the seal between the penetration fitting and the double-wall sump wall.
In still other another embodiment, each of the first and second fittings defines a bell-shaped opening. This embodiment is useful for sealing a curved conduit such as an electrical conduit to a sump wall.
Referring to
According to this embodiment, the coupler is a reducing coupler with a tapered pipe fitting 50 at a first end 52 and a slip fitting 54 at a second end 56. It should be noted that the term “slip fitting” as used in this specification is intended to refer to a fitting through which a conduit may extend, and of a configuration such that the conduit may be slid within the fitting to a desired orientation between the fitting and the conduit. Once the desired orientation is achieved, the fitting can then be sealed to the conduit. Such “slip fittings” may be distinguished from “socket fittings” which are fittings at which a length of pipe ends. According to the invention, the use of at least one slip fitting permits a continuous length of conduit to extend through the fitting, and by doing so, extend through the corresponding sump wall.
According to this embodiment, the tapered pipe fitting is a socket fitting with a tapered inner surface 58 for mating with the outer surface of an end of a secondary pipeline 60. The slip fitting has an inner diameter 62 that generally corresponds to the outer diameter of a primary pipeline 64 that is arranged coaxially within the secondary pipeline. The inner surface of the coupler at the slip fitting further defines an adhesive channel 66 which communicates with the outer surface of the coupler through an adhesive injection port 68. The use of the adhesive channel and adhesive injection port will be described in further detail later.
The change in diameter between the first and second ends of the coupler generally occurs at an inner step 70 on the inner surface of the coupler approximately midway between the integral flange and the second end of the flanged coupling. Between the tapered pipe fitting and the inner step, the inner surface of the coupler defines a circumferential rib 72 which will be described later. A threaded secondary pipeline test port 74 extends through the outer surface of the coupler to the inner surface of the coupler at the inner step toward the first end of the coupler.
In order to assemble the penetration fitting of this embodiment, the inside and outside surfaces of the sump immediately surrounding the aperture are prepared to receive a suitable adhesive such as by sanding. An adhesive is applied to the first flange face and the first flange face is pressed against the outer surface of the sump with the coupler extending through the aperture. Adhesive is then applied to both the second flange face, and to the outer bonding surface of the flanged coupling. The ring flange is slipped over the coupler from inside the sump and the second flange face is pressed against the inner wall of the sump with the inner bonding surface mating with the outer bonding surface of the flanged coupling.
Referring to
Though not shown, rather than using an assembly clamp, the flange rings may include bolt holes such that the flanged coupling and the flange ring can be bolted to one another. The use of bolted flanges is well known in the art. A bolted flange would not only hold the penetration fitting in place while the adhesive sets, it can also provide an added level of strength to the penetration fitting at the expense of requiring additional parts and additional preparation of the sump wall to accommodate the bolts.
Referring to
After an acceptable dry fit has been achieved, the primary pipeline segments and fittings are glued or otherwise connected to one another using known methods with the exception that the portion of the primary pipeline extending through the penetration fitting is not glued to the penetration fitting. Rather, before the penetration fitting and primary pipeline are adhered to one another, the primary piping system is pressure tested using known procedures to determine if there are any leaks. If a leak is detected, the corresponding section of pipe or fitting that is responsible for the leak is repaired or replaced.
Once the primary system has been confirmed to be pressure tight, the primary pipeline is glued to the penetration fitting. This is accomplished by applying a suitable adhesive through the adhesive injection port on the coupler such that the adhesive fills the adhesive channel, filling the void between the coupler and the primary pipeline. One method of applying the adhesive is using a syringe.
The various sections of the secondary piping system are then glued or otherwise interconnected to one another using known methods. For the connection between an end of the secondary pipeline and the tapered pipe fitting of the flanged coupling, adhesive may be brushed around the end of the secondary pipeline and the end is pressed into the tapered pipe fitting using well-known methods for joining tapered pipe segments. When joining the secondary pipeline to the tapered pipe fitting of the penetration fitting, the circumferential rib helps to prevent excess adhesive from clogging the secondary pipeline test port.
For those applications where there is a fixed length of secondary pipeline running between two pieces of equipment, for example, where a pipeline runs between two sumps, two or more pieces of secondary pipeline which together have a length less than the fixed length may be used in combination with a clamshell coupler to join the segments, resulting in a continuous secondary piping system running the fixed length. The use of such clamshell fittings is well known and allows longitudinal movement of the secondary pipeline during installation. In particular, when interconnecting the secondary pipeline between two penetration fittings, a length of secondary pipeline is adhered to the tapered fitting of each penetration fitting, and then a clamshell coupler completes the assembly by coupling the two pieces of secondary pipeline.
Once the secondary system has been fully assembled, it may be pressure tested by applying a test fluid such as compressed air into the annular space between the primary and secondary pipelines via the secondary pipeline test port. Because such tests must be performed periodically long after the installation has been completed, in an embodiment, one or more of the secondary pipeline test ports may be fitted with Schrader valves (not shown) which permit convenient connection of a compressed air source for pressure testing. A pressure gauge (not shown) can also be included at the secondary pipeline test port to assist in pressure testing. Any unused secondary pipeline test ports may be closed with plugs (not shown.)
Turning to
According to this embodiment, the inner surface of the coupler forms a pair of slip fittings 154, each with an inner diameter that generally corresponds to the outer diameter of a secondary pipeline 160. A primary pipeline 164 is arranged coaxially within the secondary pipeline. The inner surface of the coupler further defines an adhesive channel 166 at each slip fitting. Each adhesive channel communicates with the outer surface of the coupler through an adhesive injection port 168.
The assembly of the penetration fitting of this embodiment to the sump wall can be accomplished using a method identical to that previously described. As with the previous embodiment, once a penetration fitting has been adhered to a corresponding sump wall, the primary and secondary pipelines are dry fitted. The outer surface of the portion of the secondary pipeline extending through the penetration fitting is prepared for receiving an adhesive such as by sanding. The segments and fittings of the primary pipeline are then glued or otherwise connected to one another using known methods and the primary pipeline system is pressure tested using known procedures. If no leak is detected, the segments and fittings of the secondary pipeline system are glued or otherwise connected to one another. A suitable adhesive is applied to each of the adhesive injection ports to fill the adhesive channels and form a seal between the secondary pipeline and the penetration fitting.
Turning to
Turning now to
In this embodiment, the flange ring includes a threaded interstice test port 326 extending from an outer surface 328 of the flange ring to an inner circumferential channel 330 located at the intersection of the flange face 342 and the inner bonding surface 346 of the ring flange. The inclusion of the circumferential channel allows the interstice test port to communicate with the interstitial channels which in turn communicate with the interstice of the double-wall sump wall.
Turning now to
The penetration fitting of this embodiment is similar to that of
Assembly of this penetration fitting to the sump wall may be accomplished using methods as described above. Once the penetration fitting has been adhered to the sump wall, for the portion of the coaxial pipeline extending into the sump, a portion of the secondary pipeline is stripped from the coaxial pipeline to expose a section of the primary pipeline. The portions of the primary and secondary pipelines corresponding to the respective sleeve fittings are prepared for assembly such as by sanding their outer surfaces.
Turning to
The second flange ring further includes an optional interstice test port 527 which communicates with an inner circumferential channel 530 located at the intersection of the second flange face and an inner bonding surface 546 of the ring flange. The inclusion of the circumferential channel allows the interstice test port to communicate with the interstice 243 of the double-wall sump for reasons as described above.
The coupling further includes a tapered pipe fitting 550 at a first end 552 for mating with the outer surface of an end of a secondary pipeline 560. The coupling further includes a tapered bushing fitting 554 at a second end 556.
The penetration fitting of this embodiment further includes a reducer bushing 559 with an outer surface that mates with the tapered bushing fitting of the coupling, and an inner surface forming a slip fitting 577 with the primary pipeline 564. The inside surface of the bushing reducer includes a pair of spaced grooves 561 and 562 that receive corresponding o-rings 563 and 564. It should be noted that the o-rings do not necessarily form a seal with the primary pipeline, but rather, are intended to generally create an adhesive channel for keeping the generally viscous adhesive in place during assembly, the adhesive being applied through an optional adhesive injection port 568.
The bushing reducer further includes an optional secondary pipeline test port 574 that allows communication with the annular space between the primary and secondary pipelines after the penetration fitting is assembled. An optional extension tube 575 helps keep adhesive from blocking the secondary pipeline test port.
In assembling the penetration fitting of this embodiment, adhesive is applied to the inner bonding surface and the first flange ring is adhered to the coupling. This step may be performed during the manufacture of the coupling, or could be done by the installer before beginning work at the site. Alternatively, it may be done in the field. The coupling with the first flange ring installed is passed through the aperture of the sump wall and the first flange face is pressed against the sump wall. Adhesive is applied to the outer bonding surface of the coupling and the face of the second flange and the second flange is placed over the coupling and the second flange face is pressed against the sump wall. The penetration fitting may be held in place using an assembly clamp as described above.
As in previous embodiments, the primary and secondary pipelines are then cut to length, the joints are prepared for receiving adhesive, and the piping segments are dry-fit to one another. Then the primary pipeline is assembled without being adhered to the reducer bushing, and is pressure tested. Once the primary pipeline has been satisfactorily pressure tested, the secondary pipeline is assembled including the connection to the penetration fitting.
Once the secondary pipeline has been assembled, the reducer bushing is slid along the primary pipeline away from the penetration fitting, adhesive is applied to its outer surface and the reducer bushing is slid back into place within the coupling. The primary pipeline is then adhered to the coupling by applying adhesive through the adhesive injection port. Alternatively, if no adhesive injection port is provided, adhesive is applied over the primary pipeline at the joint with the reducer bushing at the same time that adhesive is applied to the outer surface of the reducer bushing and the bushing is simultaneously adhered to the coupling and the primary pipeline. Using this alternative procedure, it may be useful to omit the o-ring 563 closest the flange so that it does not wipe the adhesive away from the intended adhesive joint. However, for this embodiment, the o-ring 564 distant the flange is useful in wiping adhesive into place as the reducer bushing is slid into place.
Turning to
The outer geometry of this penetration fitting is also similar to those previously described, and will not be described in detail here. One important difference in this penetration fitting is that the inner surface of the coupling is of a diameter somewhat larger than the diameter of the curved conduit, and further includes a bell-shaped opening 631 at each end. The larger diameter inside the coupling along with the bell-shaped openings allow a curved conduit to more easily be slipped into place without placing undue stress on the penetration fitting. In the past, prior art rigid penetration fittings have been broken during installation of electrical conduit as the conduit is snaked through the penetration fitting and into position.
For this embodiment, a gap filling adhesive 632 is used to fill the gap formed between the curved conduit and the bell-shaped openings inside of the coupling. In one embodiment, an elastomeric adhesive is used to permit some additional flexibility after installation. While not shown, adhesive injection ports may be used to assist in the application of the adhesive.
Another option for such a penetration fitting is the inclusion of a foam spacer 633 located in the inside center of the penetration fitting. The use of the spacer prevents adhesive from blocking the interstitial ports with adhesive during assembly. In one embodiment, the foam is an open cell foam that inhibits flow of the viscous adhesive while permitting flow of less viscous fluids such as compressed air, or other fluids used for testing the integrity of the interstice. In another embodiment, a temporary foam spacer is used to temporarily prevent adhesive from blocking the interstitial ports during assembly. Such a temporary foam spacer may be made of a material that may be dissolved with a suitable solvent after assembly.
The embodiments of the invention described above have generally been directed to fiberglass fittings. Such fittings are generally made of compression molded fiberglass and are useful for connection to fiberglass sumps, and for use with systems using fiberglass pipe because the same adhesives commonly used to connect such fiberglass piping may be used in bonding the penetration fitting to the sump wall. However, in some instances, other materials may be desired. Therefore, the fittings of the present invention are not limited to fiberglass, but may be made of other materials, and in particular, may be made of polymers. Suitable polymers include polyolefins, and in particular, polyethylene and polyvinylidene fluoride.
When using materials other than fiberglass, it is important that compatible glues or adhesives be used, or that other compatible connection techniques be employed. For example, if a polymeric material such as polyolefin is used, the connections may be made using heat welding or solvent welding procedures rather than using externally applied adhesives. Furthermore, while the tolerances of the joints in the embodiments shown are generally illustrated for use with a gap-filling adhesive such as is commonly used with fiberglass fittings, tighter tolerances may be desired for fittings using solvent or heat welding assembly techniques.
It is also generally known that adhering dissimilar materials may be difficult in a field installation. For example, adhering fiberglass to polyethylene while maintaining a good, pressure-tight seal has proven difficult in the field. Therefore, still further embodiments of the present invention are contemplated as set forth below.
Turning to
Still another embodiment for use in a system with a fiberglass sump and polyethylene piping is illustrated in
Turning to
Referring to
While certain embodiments of the invention have been described, each having certain useful features, many modifications and different combinations would be apparent to one of ordinary skill in the art upon reviewing the present specification. Therefore, the invention is not to be limited to the specific embodiments illustrated, but rather, is limited only by the spirit and scope of the following claims.
This application claims the benefit of U.S. Provisional Application No. 60/747,904 filed on May 22, 2006, the entire disclosure of which is incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60747904 | May 2006 | US |
