"Flow lines — the small, low-pressure pipes blamed for a fatal home explosion in Colorado last month — have long been a weak point at oil and gas well sites.
They've been cited as the problem in more than 7,000 spills, leaks and other mishaps since the beginning of 2009, according to an E&E News analysis of state agencies' records. And that is likely an undercount because of the widely varying ways in which states report spills.
In most states, whether flow lines are involved must be deduced from inspectors' notes. In the three states that track the source of spills — Colorado, New Mexico and Texas — flow lines were cited more than any other source except tank batteries.
They're prone to corroding and leaks, lines freeze, and joints break. Rarely, they also get cut and crushed by heavy equipment."