Flex-Lok Ball Joint Pipe

Flex-Lok Ball Joint Pipe

Flex-Lok Ball Joint Pipe

AMERICAN Flex-Lok® Pipe incorporates a very flexible ball-and-socket type joint for use in such installations as subaqueous pipeline construction. The provision for significant changes in alignment, with available joint deflections of 25° for sizes 4”-12” and 15° for sizes 14”-60” in any direction, and the rugged features of AMERICAN Flex-Lok Pipe make it especially adaptable to the most difficult installations. This rugged joint configuration has an excellent record of performance, and under some of the toughest installation conditions, it has provided long life and trouble-free service. Economy and dependability have been proven in many installations under widely varying conditions.

AMERICAN Flex-Lok Boltless Ball Joint Pipe — manufactured in 4”-60” 1 sizes2 — is a rugged, boltless, flexible joint pipe designed and manufactured to assure the greatest economy in installation with maximum performance and reliability. This ductile iron pipe meets all applicable requirements of AWWA C151 and is designed to withstand severe installation and service conditions encountered in river crossings, treated wastewater outfall lines, water supply intakes, swamps, floodlands and rugged terrain where significant joint deflection may be required.

AMERICAN Flex-Lok Boltless Ball Joint Pipe provides variable deflection up to at least 15°, and the joint may be deflected to metal binding position at maximum deflection without harm to the pipe or joint components. This is a result of the unique design and functionality of the pipe and joint components. In sizes 4”-12”, the configuration incorporates the additional flexible restraint provided by AMERICAN’s Flex-Ring joint, which cumulatively results in greater joint deflection capabilities, up to 25°.

Spherical Socket

The spherical socket of the AMERICAN Flex-Lok joint is cast of ductile iron and is accurately machined to accommodate the ball of the adjoining pipe. The thick wall and bell section provides superior strength to minimize the stresses resulting from installation and service conditions.

The Flex-Lok joint gasket recess in the socket is designed and manufactured to provide easy insertion and positive seating of the gasket to avoid displacement during assembly and for constant compression of the gasket through the entire range of deflection of the assembled joint.

Spherical Ball

The ball end of the AMERICAN Flex-Lok joint is accurately machined to fit into the adjoining pipe socket and to provide constant compression of the gasket through the entire range of deflection of the assembled joint.

The inside surface of the ball is shaped so that the waterway will not be significantly obstructed at any angle of joint deflection.

Flex-Lok Gasket

The AMERICAN Flex-Lok joint uses the basic dual hardness gasket design of the AMERICAN Fastite joint that has been proven with millions of joints over approximately 55 years. Designed to provide maximum sealability, the Flex-Lok gasket is manufactured to AMERICAN’s rigid specification to assure controlled dimensional and material properties.

The snug fit of the gasket in the socket cavity, the design of the socket buttress and the hard section of the gasket act to restrain the gasket from dislodging during assembly.

Locking Systems

Two types of locking systems are used to prevent longitudinal joint separation of the AMERICAN Flex-Lok joint, depending on pipe size. In the 4”-24” sizes, the locking system employs a substantial external locking ductile iron gland and sizes 4”-12” also use the proven positive joint restraint system of the Flex-Ring joint. Both the spherical socket component and spherical ball component of the Flex-Lok joint in this size range have a Flex-Ring joint that is preassembled at AMERICAN. For 30”- 60” sizes, the joint is restrained with a ductile iron retainer ring fitted into a mating groove inside the heavy-section bell.

4"-24" Flex-Lok Pipe Joint

The locking gland of the 4”-24” AMERICAN Flex-Lok joint is cast of ductile iron. The gland has internal lugs that interlock with external lugs on the bell.

The lugs on the gland are passed between and beyond the lugs on the bell periphery, and the gland is then rotated to lock the joint and prevent separation.

All 4”-24” AMERICAN Flex-Lok Ball Joint Pipe is prepared for shipment to the job site with the locking gland strapped to the ball. These straps must be removed to free the gland for assembly. The 4”-12” configuration has a preassembled Flex-Ring joint both directly adjacent to the spherical socket and spherical ball. The locking gland is also shipped strapped to the ball.

A steel wedge with a welded-on threaded stud is provided for each 4”-24” AMERICAN Flex-Lok joint. One wedge is placed into the space between two lugs and bolted into position. This wedge provides a positive lock to prevent gland rotation after assembly.

30"-60" Flex-Lok Pipe Joint

A split retainer ring manufactured of ductile iron is fitted into a mating groove inside the heavy bell section, providing restraint against longitudinal joint separation in the 30”-60” sizes. This ring is shipped strapped to the ball. These straps must be removed to free the ring for assembly. After the ring is fitted into the groove inside the bell, a locking clip, held in place by a stainless steel spring, is inserted into the space between the ends of the ring to securely lock it into the groove.

Joint Lubricant

Special AMERICAN Joint Lubricant for underwater installation is furnished with each order to provide ample lubrication for assembly and joint flexing. This special lubricant is different from regular Fastite lubricant and is insoluble, non-toxic, will impart no taste or odor to the conveyed liquid and will not have a deleterious effect on the rubber gasket.

AMERICAN Flex-Lok Ball Joint Pipe is centrifugally cast in laying lengths shown under Standard Dimensions with the same standard outside diameters as AMERICAN Fastite or Mechanical Joint Pipe, thus simplifying tie-in connections by allowing the use of standard fittings.

AMERICAN Flex-Lok Ball Joint Pipe may be furnished with any of the coatings and linings described in Section 11. Unless otherwise specified, the pipe is normally furnished with an asphaltic coating on the exterior and with the interior cement lined per AWWA C104.

1.) Contact AMERICAN for 64" requirements.
2.) The spherical ball and socket ends of 54” and 60” Flex–Lok pipes are fastened to the barrels of the pipe with a Fastite gasket and locking ring arrangement instead of threads.


Introduction to Flex-Lok Ball Joint Pipe
4"–20" Flex-Lok Ball Joint Pipe Assembly
24"–54" Flex-Lok Ball Joint Pipe Assembly