ONE-LOK™ SERIES SLD FOR DUCTILE IRON PIPE

SIGMA ONE-LOK is a mechanical joint, wedge-action restraining gland that implements a series of individually activated wedges that locate around the circumference of ductile iron pipe. When the wedge-stem assembly is tightened down onto the pipe, the teeth (edges) on the bottom of each wedge lock onto the pipe wall. Pipe thrust causes the primary contact edge to "grab" and restrain the pipe surface. Our unique "cam action" design allows the ONE-LOK restraining wedges to rotate (and lock) into position. This positive locking feature allows the ONE-LOK to maintaing a fully restrained joint, even under variable line pressures. Under both normal operating circumstances and high-pressure surges, ONE-LOK restrainers provide full deflection of the mechanical joint within the requirements of AWWA C600.

ONE-LOK’s contoured wedges provide maximum contact with the circumference of the carrier pipe (sizes 3" through 48"). The wedges provide a wide arc or contour that evenly matches the curvature of each nominal size in ductile iron pipe. In addition to providing a more secure grip, ONE-LOK eliminates the concern of pipe wall damage or harm to the integrity of the internal lining – even on the thinnest classifications of ductile iron pipe.

ONE-LOK offers a break-off wedge stem assembly that provides the installer a “visual torque indicator,” eliminating guesswork in the trench with bolted assemblies. The twist-off top is sized exactly to the standard T-bolt and nut assembly in the mechanical joint, so there are no additional tools needed for installation. After twist-off, the ONE-LOK stem provides a residual hex shank for easy removal of ONE-LOK in service and maintenance areas. Residual shank provides visual confirmation of bolt having activated the wedge on the pipe surface. SIGMA uses a proprietary quality control process that checks every bolt’s fracture consistency before the gland is assembled and shipped to the field.

ONE-LOK’s "ball and socket" connection between the wedge and bolt and the cam action of the wedge smoothly accommodates deflection of the joint during installation, and also allows for subsidence, seismic or other forces after installation, up to the maximum allowed deflection.

ONE-LOK’s unique cam action allows the restraining wedges to “rock,” gripping the pipe wall more securely as thrust force increases.