The present invention relates to installation of and supports for line pipe, and more particularly relates to supports for line pipe (such as underground pipe lines that extend for long distances) that can be produced at relatively low cost, that are easier and less expensive to install during construction than known systems, and that lead to an improved, more efficient, more robust, and safer installation of line pipe in the field.
Long runs of pipe are made up of multiple sections of pipe welded together (or otherwise secured together) to form a long continuous length, such as for transporting liquids and gases or other semi-liquid materials long distances. This pipe is commonly called “line pipe.” In the case of line pipe that is assembled for use below the ground, a trench is dug to house the pipe. The trench is made using various tools such as a backhoe or other excavation equipment to form a continuous long trench to set the pipe in. The pipe sections are extremely long, as much as 40′ (feet) per section, and since they are often constructed in difficult/remote locations, it is virtually impossible to make the floor of the trench perfectly flat and stable. Thus, when the pipe is set down on this floor, the construction engineers are not absolutely sure that the pipe is evenly supported. This can be a problem since uneven support can lead to stress and damage to the line pipe, including both immediate damage and also delayed damage that takes awhile before it results in leakage. Such leakages are extremely expensive and difficult to repair in the field. Another problem occurs if the line pipe contacts a hard object that causes damage to the pipe (potentially undetected damage), either during construction or due to movement of earth over time causing the buried object to move against the line pipe.
Often, line pipe is welded above the ground to form the continuous length of pipe, and then the welded product is lowered down into the trench and buried. These long sections of line pipe have some flexing ability for this lay-in procedure, but are intended to lay in a more or less straight line once laid into the trench. Thus, the potential problems noted above are still present. Further, there is a need to maintain this straight line alignment in both linear and horizontal directions. There are different methods currently used to do this.
One method uses a bag filled with fine grain sand, which is then placed in the bed of the trench. These bags must be located within the trench by semi-skilled workers in order to maintain the straight line alignment and levelness of the bags along the entire length of the trench. This method requires sand of a specified grit size, and further that the bags must be transported along the entire length of the trench and manually lowered into the trench. The workers must get into the trench and place the bags accordingly, which is a messy and potentially unsafe position for workers. Pipe lines are known to extend for hundreds of miles, so this is a costly operation that must be repeated along the entire length of the line. This method is manually intensive, and further transport of the sand and bags to the construction site is expensive due in part to their weight.
A second method uses a special truck containing foam-making equipment. The line pipe is lowered into the trench and an operator that is skilled in the application of foam will lay a bed of foam under and around the pipe to support the line pipe. Since there is a certain cure time for the foam, this is a time-consuming process that requires that the pipe be held in a specific location, both horizontally and laterally, for a length of time necessary to cure the foam sufficiently to support the line pipe. Several operators and an expensive truck equipped to carry and spray foam must travel parallel to the trench along the entire length of the line pipe. Any mechanical breakdown of either the foam-making equipment or the truck will slow down the process of laying the pipe. Further, the foaming chemicals, which are potential environmental pollutants, must be transported over difficult terrain.
The present invention provides for a solution to support line pipe in a much easier and concise manner than previously existed. Instead of filling sand bags or forming a pipe support on site by foaming in place, the present invention includes providing a profiled block of foam cut to form a support (also called a “foam block support” herein) that can be snapped onto the line pipe at any interval and then manipulated to a bottom-facing use position on the line pipe, such as one being at or near a longitudinal center of the pipe and others being along the line pipe at various spaced locations, such as at a distance of about 2 to 3 feet from the welded joints at ends of pipe sections. Since the design of the profile is consistent for each piece, the pipe will be inserted within the trench in a manner that allows the foam block to control the height of the pipe within the trench in a consistent manner Advantageously, the physical properties of EPS (expanded polystyrene) are such that the profile of the foam block can be made to include two opposing fingers that permit snap-on attachment to the pipe, but that are designed to allow an unskilled operator to place them over the pipe (such as onto a top of the pipe) and then adjust their longitudinal and/or rotational position to avoid incorrect placement or misalignment when the line pipe is placed in the trench. Gravity assists in assembling the supports onto the line pipe and also in rotating the supports to use positions under the line pipe to form a base parallel to the ground (or floor of a trench). Testing shows that the physical properties of EPS foam material are such that the present foam block supports readily support a weight of the line pipe, and are not adversely deformed by the weight.
In one aspect of the present invention, a support is provided for line pipe with known diameter, where the support includes a foam block cut to define a concavity shaped to receive the line pipe of known diameter.
In another aspect of the present invention, a method comprises steps of providing interconnected pipe sections forming a line pipe construction; placing pre-formed foam supports on the interconnected pipe sections; and resting the line pipe on the foam supports and the foam supports on a floor surface to thus support the line pipe.
An object of the present invention is to use the physical properties of EPS to provide a support designed to allow for a safe and effective and more efficient method of construction/installation, and further that allows a relatively easy delivery of material to the worksite due to its light weight and durability.
An object of the present invention is to utilize EPS material in a support for line pipe, taking advantage of the EPS material's very lightweight material, such as by making foam block supports out of densities of approximately 3 pounds per cubic foot, or even 2 pounds per cubic foot, or in many applications even 1 pound per cubic foot.
An object of the present invention is to construct a support that is made of a material that is environmentally safe and relatively inert, such that its use does not create an environmental hazard.
An object of the present invention is to make foam block supports that can be placed along the path of the pipe trench with very little physical effort on the part of an unskilled worker.
An object of the present invention is to construct a line pipe support that can be inserted onto the line pipe by an unskilled worker without ever having to enter the trench to arrange bags or use equipment to foam in place.
An object of the present invention is to provide foam block supports that provide flotational support of line pipe across soft land areas and swampy areas, even where there is a presence of water.
An object of the present invention is to allow pipe sections to be welded together in a pre-build of the line pipe above the ground, and then have a means to support the pipe across the surface of the water before intentionally submerging the pipe to its final resting position underwater.
An object of the present invention is to construct a support for line pipe that is lightweight but is capable of supporting up to about 70 pounds per cubic foot.
An object of the present invention is to construct a support for line pipe from a foam block that will allow the line pipe to float until such time that it is desired to sink the pipe to its final location below the water level.
An object of the present invention is to construct a foam block support from low density foam, such as less than 3 pounds per cubic foot—and in many applications as low as 2 pounds per cubic foot or even 1 (or less) pound per cubic foot.
An object of the present invention is to construct a support with opposing fingers having a profile that allows them to resiliently slide over a round surface without permanent deformation (i.e., the supports can be snapped onto the line pipe in a self-retaining position), where the fingers hold the entire mass of the block suspended on the line pipe yet permit fine adjustment on the supports on the line pipe.
An object of the present invention is to provide foam block supports shaped to support pipe diameter of 1 inch to 48 inches, yet where a total weight of the supports are less than about 50 pounds, and more typically less than about 10 pounds, and in many circumstances less than 5 pounds.
An object of the present invention is to provide foam block supports shaped to support line pipe, above or below ground, and through various and different ground compositions, including different levels of moisture content and even high water content.
These and other aspects, objects, and features of the present invention will be understood and appreciated by those skilled in the art upon studying the following specification, claims, and appended drawings.
A series of contoured pipe supports 20 (
The illustrated support 20 (
The present invention provides for a solution to support line pipe in a much easier and concise manner than previously existed. Instead of filling sand bags or foaming in place, the present invention includes providing a profiled block of foam cut to form a support that can be snapped in place over the line pipe at any interval. Most commonly foam supports are placed at or near the center of the pipe and at a distance of about 2 to 3 feet from the welded joints. Since the design of the profile is consistent for each piece, the pipe will be inserted within the trench in a manner that allows the foam block to control the height of the pipe within the trench in a consistent manner. Advantageously, the physical properties of EPS (expanded polystyrene) are such that the profile of the foam block can be made to include two opposing fingers that extend above the center of the line pipe. These fingers are designed to allow an unskilled operator to place them over the pipe (such as onto a top of the pipe) without fear of incorrect placement or alignment when the line pipe is placed in the trench. The foam supports can be adjusted along and/or around the line pipe after being placed on the line pipe. With the help of gravity, each foam block is rotated in place to a position under the line pipe to form a base parallel to the ground (or floor of a trench).
Testing has shown that the physical properties of EPS foam material are such that the weight of the pipe when exerting a load on the foam block supports will not adversely deform the foam block supports if appropriate densities of foam material are selected. Hence, a weight of the pipe will not affect the ability of the foam block supports to set substantially on the surface of the trench bed and allow for easy alignment and protection of the line pipe.
In addition to the physical properties of EPS, the design of this product allows for a safe and effective method of construction/installation, and further allows a relatively easy delivery of material to the worksite due to its light weight and durability. For example, EPS is a very lightweight material, and foam block supports can be made of densities of approximately 1 pound per cubic foot (or lower, especially with tolerances) to as much as 2 or 3 (or higher if required) pounds per cubic foot. Further, this material is easily transportable. Still further, the material is environmentally safe and relatively inert, such that its use does not create an environmental hazard. The foam block supports can be placed along the path of the pipe trench with very little physical effort on the part of an unskilled worker. The EPS material can be inserted on the line pipe by an unskilled worker without ever having to enter the trench to arrange bags or use equipment to foam in place. Further, there is no need for a worker to wait until a foam mixture has cured sufficiently to support the weight of the line pipe.
In addition to mechanical supports, these same blocks can be fashioned to permit the flotation of line pipe across soft land areas, even where there is a presence of water. In some cases, it is necessary to lay line pipe across bodies of water. In these instances, it is advantageous to build the pipe above the ground and then have a means to support the pipe across the surface of the water before intentionally submerging the pipe to its final resting position underwater. In this case, an EPS foam block support can be designed to substantially support the weight of the pipe as a flotation device. For example, EPS is capable of supporting up to about 70 pounds per cubic foot. By a simple calculation of the weight of the pipe, it is possible to design a foam block support that will allow the line pipe to float until such time that it is desired to sink the pipe to its final location below the water level. At that time, the line pipe can be sunk by known means, such as by using cement or other heavy material to weigh down the assembly.
Notably, the present foam block support includes various features that facilitate and optimize its function and use during construction. The illustrated foam support is preferably made from a low density foam, such as less than 3 pounds per cubic foot—and in many applications as low as 2 pounds per cubic foot or even 1 pound per cubic foot (+/−tolerances, thus often down to 0.8 pounds per cubic foot). The opposing fingers have a profile that allows them to slide over a round surface without permanent deformation (i.e., the supports can be snapped onto the line pipe in a self-retaining position). The profile fingers hold the entire mass of the block suspended on the line pipe. The profiled fingers deflect when a force is applied in the direction of the center of a round object such that they stay substantially about the center of the round object. When the force that causes the block support to relocate to the center of the round object is removed, the block support will remain substantially about the center of the round object. The foam block supports are useful as a flotation supporting system for line pipe. A wide base surface of the foam block supports allows the center of a supported pipe to locate close to the bottom of a body of water (e.g., a lake bottom). Despite the foam block support's durability and size, an entire block weight of a typical support for a pipe diameter of 8 inches to 48 inches is less than about 50 pounds, and more typically less than 10 pounds, and in many circumstances less than 5 pounds.
It is contemplated that a proportional increase of finger interference can be provided for successively larger diameters of the line pipe. It is contemplated that a single large block of foam can be cut to produce a plurality of foam supports for large diameter line pipe. It is further contemplated that a same large foam block or sheet can be used to cut a plurality of different supports for large and small supports, with the small support being cut from the scrap foam taken from the concavity of a larger support. It is also contemplated that a long log-like profile can be cut with a shape like that shown in
The present block support includes specific details of the profile that are intended to perform in like manner despite its increase in physical size. Since there are specific specifications for pipe (also called line pipe), the features that make up the predominate profile repeat themselves as the pipe sizes increase. The base material of the illustrated block support is lightweight foam, such as 3 pounds per cubic foot or more preferably 2 or even 1 pound per cubic foot. The results are low-weight, high-load-bearing capacity profiled block supports of 10 pound or less. The weight of the supports could be somewhat higher for large pipes up to 48 inches in diameter. These low-weight block supports can easily be moved and lifted to a position that allows easy installation around the pipes. The exterior surface of the blocks are non-finished lightweight foam as is caused by heating a wire and cutting the surface of a virgin raw block of foam with this heated wire. The shape is preferred to be flat on the bottom to allow the support to have good stable contact with a flat floor surface or a shaped trench produced by conventional machines for such purpose.
The blocks are each based on a conventional size to accommodate common pipe sizes. For example the illustrated block support (
The foam block preferably should be such that the lowermost section of the pipe profiled surface to the base allows sufficient distance from the lowermost section of the pipe to allow for variation in the trench without the line pipe contacting the trench floor along the length of the line pipe.
The load-carrying capability should preferably be such that the compressive resistance of low density foam at 1% deflection has a safety factor of about 100% relative to the load-carrying capability of foam based on a factor of 7.0 pounds per square inch. The flotation characteristic of the illustrated block support is about 70 pounds per cubic foot.
It is contemplated that the present foam block supports are also useful for supporting utility-carrying line pipe, which can be 1-2 inch diameter pipes, buried underground.
Modified supports are shown in
The illustrated support 20A is precast EPS foam block having a concavity 23A generally matching a diameter of a pipe section 22, and includes opposing fingers 24A, an angled surface 25A, and a flat bottom surface 26A adapted to stably engage the ground, similar to the support 20 noted above. Like support 20, the support 20A provides for a solution to support line pipe and for installation method that are much easier than in known prior practices. Further, support 20A minimizes material volume while maximizing material at strategic locations for optimal strength, durability, robustness, and ease of installation (including low weight).
Specifically, support 20A (
Notably, the supports can be made of multiple parts (i.e., two, three, or more pieces) where a size or other consideration makes it desirable from a manufacturing standpoint to make and assemble (either at a factory or at a job site) smaller sub-components. For example, a modified support 20B (
It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present invention, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise.
This application claims benefit under 35 U.S.C. §119(e) from provisional application Ser. No. 61/110,663, filed Nov. 3, 2008, entitled FOAM SUPPORT FOR LINE PIPE.
Number | Date | Country | |
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61110663 | Nov 2008 | US |