Restrained Joint Pipe Assembly Extension Procedure

In some installations of restrained joint pipe, it is desirable to pull-extend (or take the "slack" or movement out of) installed restrained joints. In traditional backhoe or bulldozer push-on pipe assembly, it is most common for the installer to push-assemble the latest installed pipe into the line. In applications where restrained joints are to be extended, however, and particularly in some exposed lines, the pushing operation can unnecessarily disturb previously extended joints. In such cases, some very simply designed rigging (using the same heavy equipment) can ensure that only pulling loads are applied to previously extended joints as new joints are assembled. One such rigging method, utilizing a snatch block (with pulley and hook), a wire rope pulling cable, and a pipe end hook is illustrated in the photograph at left. Of course, a simple wire rope "choker cable" can be substituted for the chain around the pipe bell shown in the same photograph.