Evaluating the Performance of the Zap-Lok Connection System

The Zap-Lok connection system involves a bell, or expanded area, formed on one end of a joint of pipe, and a groove is formed on the opposite end. Both end-forming operations are accomplished with a hydraulic belling unit and a hydraulic groover, respectively, operated by hydraulic power units. These end preparations are automatically controlled to specifications required for the Zap-Lok joint. In the field, or on the right-of-way, the belled end of one length of pipe and grooved end of another are forced together by the Zap-Lok joining press, with a thin coating of epoxy serving as a lubricant. The Zap-Lok joint is made cold and formed from the pipe itself. This process takes about 10 seconds, and it is normal to average 90 seconds per connection, including driving to the next joint. In the drive to lower costs for oil and gas operators, Zap-Lok is seen as a way to reduce costs of pipeline construction by 25% to 30% on land and by 45% to 60% offshore. Over the past several years an extensive testing program has been undertaken by Zap-Lok to evaluate the performance of their system, especially in relatively shallow water applications. This paper provides details on specific phases of the research program and the insights that were gained in the evaluation effort.