Stone Kinesis Pipe

The Stone Conductive Pipe transports BuildCraft energy (MJ) after it has been extracted by a Wooden Conductive Pipe from an engine. In v.3.70+, they simply have a maximum energy input and any more will make the energy "wire" inside the pipe to turn red indicating a bottleneck which will only allow the amount of energy the pipe can handle. The Stone Conductive Pipe loses 5% MJ per pipe, making it highly inefficient compared to Gold Conductive Pipes 0.5% energy loss.

Older Versions
Max MJ Traversing on Conductive Pipes was technically 9,999 MJ/t, because upon reaching 10,000 MJ stored, the pipes would explode. It was very hard to reach this limit, though. Stone Transport Pipes do not explode in v.3.70+. They simply turn red, and form a bottleneck.