FIELD OF INVENTION

The invention relates generally to natural gas plumbing systems and in particular to a pre-assembled plumbing system.

BACKGROUND OF THE INVENTION

Plumbing systems often use pipes, valves, plumbing fixtures, tanks, and other apparatuses to convey fluids to an appliance. Examples of commonly used plumbing systems include heating and cooling (HVAC), waste removal, and potable water. Unlike above-grade plumbing installations, underground systems need to perform in harsh and corrosive environments.

Natural gas supply conduits for residential and industrial use are often buried several feet below the ground surface. One type of natural gas plumbing system uses black iron pipe. This piping encases a natural gas supply within a thick-walled metal pipe. As a result, accidental nail strikes don't easily puncture iron gas pipe, and it takes extreme force to bend or break the pipe.

Black iron piping is popular due to its low price. Additionally, there are a number of resources available to consumers about installing iron gas pipe or plumbers who work with iron gas pipe.

However, iron gas pipe installation is time-consuming. Plumbers must cut the rigid pipe to specific dimensions and manually or automatically thread the pipe's ends. Additionally, black iron pipe exposed to moisture can rust and corrode. In severe cases of rust, a hole can be created in the buried gas pipes such that gas escapes into the surrounding environment through the hole.

Another form of gas piping is corrugated stainless steel tubing (CSST). CSST is flexible piping that commonly runs between rigid gas supply lines and individual appliances. Although CSST's use is generally restricted to this type of application, some municipalities allow the use of CSST for entire supply systems. The pipe fittings attached to each end of a length of CSST connect to appliances or rigid pipe fittings.

Various plumbing and mechanical codes require that such installations of CSST be protected. Typically, protective conduit is placed in underground installations and the flexible piping is positioned in the protective conduit by pulling the flexible piping through the protective conduit. Pulling the flexible piping through the protective conduit on-site creates excess labor and increases the cost of installing flexible piping.

Additionally, gas lead-in assemblies are commonly employed at the location where the buried piping approaches the gas meter or other fitting mounted above grade. Traditional assembly methods include welding two or more components together. The welding operation often requires elevated temperatures, which can adversely affect any plastic or elastomeric component and increase the time and cost of installation.

To overcome some of the above disadvantages, professionals may use transitional risers to connect plastic piping with iron piping above grade. This process often includes developing a coordinated plan between a gas contractor and a builder, which may require multiple trips to the construction site, delay installation, and increase cost.

Accordingly, there is a need for a system and methods by which plumbing systems are preassembled using flexible gas piping and adjustable components for efficient installation. The present invention satisfies this need.

SUMMARY

The invention relates generally to natural gas plumbing systems and in particular to a pre-assembled plumbing system. More specifically, the present invention relates to a plumbing system that is preassembled to a large extent at a manufacturing site prior to shipping to the site of installation.

The pre-assembled plumbing system may be easily installed and may include a flexible gas pipe, a transition riser, and a lead-in assembly. The lead-in assembly may include a swivel joint configured to provide 360 degrees of multi-plane range of motion. The plumbing system may be coiled for storage and then transported to a site. Advantageously, the plumbing system is manufactured and sold as a single pre-assembled unit, thereby facilitating the ease and speed with which the plumbing system can be installed.

In one aspect, the pre-assembled plumbing system may include a transition gas riser coupled to a gas pipe. The transition gas riser may encompass a portion of the gas pipe below grade. Further, the system may include a lead-in assembly coupled to a riser head assembly of the transition gas riser. The lead-in assembly may include a swivel joint configured to rotatably couple a valve.

The gas pipe of the pre-assembled plumbing system may be a polyethylene gas pipe and/or another suitable material that is flexible material capable of being coiled prior to installation. In certain embodiments, various components of the system may be joined by heat fusion and/or mechanical type fittings.

The transition riser of the pre-assembled plumbing system may include an inner diameter that is greater than the outer diameter of the gas pipe. Further, transition gas riser may include a moisture seal configured to prevent groundwater and other contaminants from entering the radial space between the gas pipe and the transition riser. In certain embodiments, the transition gas riser may include an indicator, such as indicia for designating the position of the riser head assembly.

The riser head assembly of the pre-assembled plumbing system may include a swivel body, a stiffener, a compression ring, and a swivel nut. The compression ring may further include a spring-steel ferrule configured to form a seal.

The lead-in assembly of the preassembled plumbing system may be made of a stainless-steel material. A valve of the lead-in assembly may be a ball valve for controlling the flow of a liquid or gas. A key may be used to open and close the valve. The valve may be coupled to a burner pipe via an elbow for delivering natural gas to, for example, a fire pit.

The swivel joint of pre-assembled plumbing system may include a stationary member and a rotatable member. The rotatable member may be configured to provide 360 degrees of multi-plane range of motion. The stationary member and rotatable member may be substantially cylindrical and include a substantially elbow-shaped profile. A sealed bearing may be used to couple the stationary member to the rotatable member.

While the invention is susceptible to various modifications and alternative forms, specific exemplary embodiments thereof have been shown by way of example in the drawings and have herein been described in detail. It should be understood, however, that there is no intent to limit the invention to the particular embodiments disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims.

