CIP LINERS – HANDLING TOUGH SITUATIONS IN GAS OPERATIONS

摘要

Since GTI sponsored the introduction of cured-in-place (CIP) liners for gas in the early 90’s, utility managers have begun to recognize and utilize CIP liners to solve some of their toughest maintenance concerns. Finding, repairing and taking steps to prevent gas leaks consume a large portion of an operator’s time and money. This paper will discuss how curedin- place liners provided several gas utilities with an attractive alternative to solving more costly or risky pipe maintenance concerns. PSE&G was experiencing an increasing rate of leaks at joints along a 1600 foot segment of 16 inch cast iron main that crossed an elegantly landscaped golf course. Conventional construction alternatives, joint repair, open-trench installation, or boring would have been expensive, disruptive, and even risky to employ along this route. CIP lining on the other hand, involved minimum excavation on the golf course, sealed all existing leaks along the main, provided protection against future joint and corrosion leaks, was most acceptable to the residents and golf course operator, and provided PSE&G with a cost-effective solution to the maintenance concern. Several utilities were dealing with a common maintenance problem, leaks on gas lines that had been installed underneath the floor slab of the residence. This situation presented a number of construction challenges for the gas crew. The inconvenience to residents and necessary destruction of personal property to either relay the service or insert the new service line were important factors when seeking a solution. With lining, there was less digging and no additional house piping required. Additionally, the job that usually took several days to complete was finished in hours with a liner. As important, the residents were not subjected to noise, dust, and inconvenience of traditional renovation activities. When PGW was notified of a major renovation project that would parallel a large segment of their 20 inch cast iron main, they had an important decision to make. Despite the reliable performance of this older large diameter main, major construction work in close proximity to the pipe could create leaks along their pipe. Additionally, the substantial restoration work that would follow would raise the cost of subsequent leak repairs dramatically. Lining the structurally sound cast iron pipe was the utility’s choice. Lining would not only seal any existing leaks, but would also eliminate the risk of potential leaks developing as the result of construction activities and provide a cost effective solution for PGW’s Operations staff.