On August 21, 2004, about 8:54 a.m., a natural gas explosion destroyed a residence located at 48 Woodland Lane in DuBois, Pennsylvania. The two residents were killed in this accident.
We determined that the probable cause of the leak, explosion, and fire in DuBois, Pennsylvania, on August 21, 2004, was the fracture of a defective butt-fusion joint and the failure of the National Fuel Gas Distribution Corporation to have an adequate program to inspect butt-fusion joints and replace those joints not meeting its inspection criteria.
As a result of this investigation, we made the following new safety recommendations.
To the Pennsylvania Public Utility Commission: Require an analysis of the integrity of butt-fusion joints in National Fuel Gas Distribution Corporation’s gas distribution system and replacement of those joints that are determined to have unacceptable characteristics. (P-06-1)
To National Fuel Gas Distribution Corporation:
- Revise your butt-fusion procedures for plastic pipe to include a requirement for determining drag force in the field for each butt-fusion joint. (P-06-2)
- Revise your initial qualification and requalification procedures for plastic gas pipe to ensure fusers produce test joints made from coiled pipe with characteristics similar to those experienced in the field. (P-06-3)
To USPoly Company: Revise your butt-fusion procedures to include a requirement for the avoidance of mitering in plastic gas pipe joints. (P-06-4)
To the Plastics Pipe Institute: Revise your butt-fusion joining procedure for plastic gas pipe to (1) stress the importance of inspecting the finished joint, (2) include guidance on the joining of
coiled pipe, and (3) include a requirement for the avoidance of mitering. (P-06-5)
