Methods of Installation

Time and time again, AMERICAN Ball Joint Pipelines have been installed where the conditions of the job site have challenged the ingenuity of the design engineer and installation contractor. The design features of Flex-Lok Pipe make it readily adaptable to extremely difficult situations. It has been installed by a variety of methods - both unique and conventional - with an unexcelled record of success. Many installations have been made utilizing floating equipment, thus eliminating all underwater work. Unnavigable and navigable waters have been crossed with all jointing and installation work being performed on the opposite banks, with appropriate design and construction planning. The majority of installations involve one or more of the installation procedures described as follows:

Installation from Bank (Line Pulling)...

In many instances it is possible to plan installation methods for waterway crossings so that work will be confined to firm ground with offshore operations minimized or eliminated. The Flexible Joint pipe may be assembled on an inclined ramp, or on launching ways, and pulled to the opposite shore by cable. The entire line may be moved as a unit or in sections. The line may be floated or pulled directly into an excavated trench depending on existing conditions.

AMERICAN Flex-Lok Joint Pipe is positively locked against separation and the allowable end pull permits the assembled pipe to be pulled as a line into otherwise inaccessible areas such as rivers, swamps and quicksand. The joints are designed so that the joint sealing is not affected by the tension of pulling, and after the line is in final position, no further joint work is necessary. Many installations have been made by this method, and on several occasions two or more parallel lines have been pulled simultaneously.

In the construction of a ramp, the most readily available materials can be utilized, such as timbers, rails or steel beams. Pipe may be assembled so that the heavy flanges are in contact with the ramp or the pipe may be cradled on cross supports equipped with guide cleats. The design of the ramp and the materials used dictate how the pipe should be supported. The deflection of individual joints provides line flexibility, enabling movement through moderate bends into various elevations and locations. The grade and long radius bend of the ramp are planned for gradual line deflection and maximum control of line movement.

In line pulling, analysis of bottom conditions should be made by thorough soundings to determine possible obstructions and resistance to be encountered by the pipe, as well as support for the pipeline in contact with the bottom.

Closure pieces with cable eyes and test taps can be furnished with the pipe on a rental basis.

An advantage is sometimes obtained by fastening an improvised deflector or sled in front of the lead socket flange.

Line Flotation...

AMERICAN Flex-Lok Joint Pipe can be installed by various methods of line flotation. Some sizes of unfilled pipe are lighter than the water they displace and will float. See Table Nos. 10-1 and 10-2. If the unfilled pipe is heavier than the water it displaces, then pontoons must be secured to the line to provide the buoyancy if flotation is desired.

Unless bottom conditions or other circumstances dictate that the line be floated into position, it is usually better to pull the line submerged along the bottom with slight negative buoyancy. When necessary, pontoons may be used to lighten the weight of a long line pulled along the bottom.

Unless water depth is relatively shallow, approximately 10' or less, a line floated into position should be supported as it is lowered to the bottom. This precaution is necessary to avoid placing excessive deflection and beam stresses on the joints.

Used commercial steel drums are generally available and often can be economically used as pontoons during installation. In designing flotation gear, consideration should be given to the depth at which the drums used will collapse due to external pressure.

Installation from a Barge...

Designed especially for submarine installations, AMERICAN Flex-Lok Joint Pipe is adaptable for installation from practically any barge or other type of floating equipment which can be utilized for laying pipe from the water's surface. The ruggedness and flexibility of the Flex-Lok Joint permits the suspension of the end of the pipeline above water for the addition of pipe, while the balance of the line is suspended on a launching ramp, or rests on the bottom.

Normally, a ramp is employed in conjunction with the barge for the best control of movement, prevention of undesirable bending loads on joints, and for ease of operation. The ramp is designed to reach from the barge to the bottom and to rise and fall with the changing bottom elevations. As pipe is added onto the suspended end of the line, the barge is moved forward, pulling the ramp from under the suspended section, allowing it to progressively descend to the bottom. Care should be taken to prevent any barge movement that could cause damaging overdeflection and bending moments to occur in the pipe joints.

Recommendations

Installation
The outstanding construction advantages afforded by AMERICAN Flex-Lok Pipe should be fully considered and utilized for long, trouble-free service.
For example, where river bottoms are of unstable soils, the flexibility of Flex-Lok Pipe will allow substantial line movement or settlement, and remain leak-free. Movement of the installed line, however, should be minimized as far as practical and confined to the underwater section of the line. It is suggested that the river bottom be trenched or dragged to stable soils where practical. Also, the ends of the lines extending above the water should be stabilized for connection to other lines. It is generally suggested that the ends of the crossings be installed in firm earth, above the high-water mark, to provide firm anchorage. Where the connecting ends of the crossings cannot be located in firm soils, other suitable means of anchoring should be provided.
After a river crossing is installed, it is normally suggested that the line be back-filled and allowed to settle for a reasonable period before end connections are made. This is due to uncertain bedding conditions that may be present in many installations. Submerged lines should be filled with water to aid their settlement.
The liberal deflection provided by AMERICAN Ball Joints practically eliminates the need for line fittings; however, where steep approaches or horizontal bends are encountered requiring greater than normal line deflection, the use of short AMERICAN Ball Joint Connecting Pieces will provide additional deflection within a short distance.

Testing
Upon completion of a river crossing, the ends of the line may be closed for testing by the use of closure pieces which are available on loan from AMERICAN.

Connections
When connecting Ball Joint river crossing lines to land lines, the river crossing pipe should normally be installed first.
Sleeves are often used for connecting Ball Joint pipe to other pipelines. Such connections facilitate the joining of a field-cut piece, allow moderate movement of the river crossing ends, reduce stresses, and provide for easy line maintenance.
Long pattern mechanical joint sleeves are recommended for making connection to mechanical joint or Fastite joint ductile iron pipe, both of which have the same outside diameters as Ball Joint pipe. Connections to pipe of other diameters require special connecting pieces, designed to fit specific installation requirements.
The judicious use of ball joints with or without special restrained expansion sleeves may be advantageous in seismic environments.

AMERICAN will assist in any river crossing project by making a detailed layout and by giving suggestions for installation procedures to accomplish the crossing.