|
|
|
|
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
Law Offices of
George H. Lyons
(602) 912-3888(phone)
(866) 912-3888(toll-free)
(602) 912-3898(fax)
|
|
|
|
|
|
|
|
|
ABS
Phoenix was home of one of the gas utility innovators in adapting ABS (acrylonitrile-butadiene-styrene) in various diameters for use both as gas pipe feeder mains and gas service lines to gas meters. ABS is generally black in color and today is primarily used as sewer piping material throughout the United States. ABS gas piping in the two inch diameter size was generally used as multiple installation feeder main piping during the late 1960s and into the early 1970s. ABS in smaller diameter sizes (usually ˝ inch) was extensively used as gas service line material (service lines are generally viewed as the line that takes gas from the feeder main to the meter). ABS’ rigid form and unique chemistry requires the use of “novel” joining procedures for adaptation of ABS plastic as a gas piping material.
In the Phoenix area, ABS gas mains (normally long pieces of pipe in two inch diameter settings) were frequently connected to each other or “joined” by use of mechanical pressure fittings. Arguments are available that these mechanical pressure fittings were never intended to be used as part of a gas distribution system, but rather were intended for far less stressful environments. Over the years, many of these “mechanical” pressure fittings failed. While there are various failure mechanisms, one of the failures frequently encountered was the result of the mechanical coupler’s slippage when placed in an unfavorable level of stress.
ABS service lines were installed in a wide range of areas in the Phoenix area. Like the ABS feeder mains, the ABS service lines were rigid; however the normal method for connecting the service lines was through use of solvent fusing of material. Because of the locations of many gas meters in reference to the gas main feeder pipes, the service lines frequently had to take paths involving changes in direction resulting in sharp angles of installed piping. These angles were natural stress riser points.
During the period when ABS was being extensively used for gas piping, the industry became aware that this type of pipe had sensitivity to certain chemicals. The pipe, once exposed to specific chemicals, would gradually lose its rigidity and utility. Some chemicals were actually thought to dissolve the ABS material over time.
Because of the number and severity of gas explosions that occurred with the ABS material starting in the mid-1980s, a program was adopted to remove the ABS material. However, there are no assurances that all of the ABS was found and removed. ABS is no longer used as new gas piping material in this area. An interesting analysis of one of the problems associated with the use of ABS as a gas piping material can be reviewed by reference to the NTSB report dealing with one of the explosions Mr. Lyons was responsible for investigating.
Mr. Lyons has been involved in most of the large gas explosion litigation related to ABS pipe failures in the Arizona system. Most of these cases have involved extensive pipe failure analysis. Several of these cases have resulted in settlements or verdicts in excess of multiple millions of dollars.
|
|
ABS
PVC
Polyethylene
Joint Utilities Trench Explosions
Odor/Odorless Gas
Propane Gas v. Natural Gas
|
|
|
|
|
|
|
