Oklahoma Court Sends CSST Case to Jury

Since its development in Japan in the 1980s to mitigate earthquake hazards, and its subsequent introduction to the U.S. market in the 1990s, corrugated stainless steel tubing (CSST) has consistently spawned litigation.

In the latest court decision involving CSST, an Oklahoma federal court denied a defense motion for summary judgment, ruling in March that a property loss claim against a CSST manufacturer could be heard by a jury because there was sufficient evidence to support a product defect claim. The case is Oklahoma Farm Bureau Mutual Insurance v. Omega Flex Inc.

Advantage & Vulnerability

CSST is used instead of rigid black iron pipe for gas piping inside a structure. Its advantage is flexibility, which makes it much easier and quicker to install as indoor piping. But this advantage is also the source of a potentially serious vulnerability. CSST’s walls are much thinner than those of traditional rigid piping.

So, if a structure is impacted by a lightning strike and CSST inside the structure is close to an ungrounded conductor, electrical arcing can burn a hole in the CSST. The resulting gas leak can be ignited (often by the heat of the arc), and if there are combustibles nearby, a serious structure fire can ensue. (These kinds of CSST failures rarely result in an explosion because the leaking gas usually ignites before a large volume of gas accumulates.)

The typical CSST lawsuit is brought by a property insurance carrier seeking to be reimbursed for money paid to a homeowner due to a structure fire. In a legal process known as “subrogation,” the insurance company stands in the shoes of the insured homeowner and may sue any party that has caused the loss in order to recover the amounts paid to the homeowner. In the case of CSST, these insurance carriers generally target the CSST manufacturer, contending that the product is defective because of its vulnerability to lightning strikes.

Bonding & Grounding

Bonding of the CSST to a structure’s electrical service grounding electrode system will certainly help protect the CSST against lightning strikes, although there is some question whether it helps when there is a direct strike on the structure. Bonding and grounding requirements are included in the standard manufacturer’s installation instructions and have for years been incorporated into NFPA 54 and other industry codes.

The Oklahoma case involved a fire allegedly caused by a lightning strike that impacted CSST that was not properly bonded and grounded as required by NFPA 54 and the manufacturer’s instructions. On July 11, 2020, lightning struck the home of Michael and Sondra Diel in Enid, Oklahoma. The lightning struck the drip edge at the northern peak of the Diel home, which had visible evidence of damage. After the strike, a fire started in the Diels’ attic above the kitchen and below a utilities bundle, consisting of coaxial cable, household electrical conductors and Omega Flex-manufactured TracPipe CSST. The CSST in the Diel home was not bonded and grounded properly.

Subrogation Lawsuit

After the fire, the Diels filed an insurance claim, and their insurance company, Farm Bureau, covered the loss and paid for the Diels to build a new home. Subsequently, investigation revealed a hole in the CSST in the area of ignition of the fire, and Farm Bureau filed a subrogation lawsuit against Omega Flex to recover the money that it had paid to the Diels. In the lawsuit, Farm Bureau claimed that Omega Flex’s CSST was defectively designed, and that it caused the attic fire in the Diels’ home.

Omega Flex responded with a motion for summary judgment. It argued that Farm Bureau could not show that the CSST was defective, and that in any event the CSST did not cause the fire at the Diel home. The hole found in the CSST after the incident, it argued, was not caused by lightning.

Moreover, it argued the hole did not cause the fire, and the CSST was not properly bonded and grounded in accordance with code and the Omega Flex instructions. It contended that if the CSST had been properly bonded and grounded, the lightning strike could not have caused a hole to form in the CSST.

‘Battle of Experts’

Omega Flex also filed motions to disqualify the Farm Bureau experts who offered opposing opinions. In a separate ruling the court found the experts to be qualified to offer their opinions and that these opinions were sufficiently reliable to be admitted in evidence at trial. In the end, this ruling proved fatal to the motion for summary judgment.

The court first addressed the claim that the hole in the CSST was caused by lightning. It noted its ruling on the experts and stated:

“The parties’ experts disagree as to whether the hole found in the CSST was caused by lightning. Therefore, in this battle-of-the-experts scenario, the jury will be given the opportunity to evaluate what weight and credibility each expert opinion deserves.”

Case-Specific Testing

The court took the same approach with the claim that the hole in the CSST did not cause the fire. Omega Flex argued that Farm Bureau did not offer competent evidence that the arcing event that caused the hole could have caused sustained ignition of the escaping propane, which would have been necessary to ignite a larger attic fire. It also said that Farm Bureau’s experts did not conduct “case-specific testing” and did not conclusively rebut Omega Flex’s expert’s conclusions as to whether the hole caused the fire. The court again ruled that the “battle of experts” was for the jury to resolve.

Omega Flex had also argued that the CSST in the Diels’ attic was not properly bonded, and the “fact that the installer failed to follow Omega Flex’s installation instructions destroys the causal nexus between the alleged defect and the fire.” Omega Flex again pointed to the lack of “case-specific testing” conducted by Farm Bureau’s expert. But the court again ruled that the “battle of experts” on this point was for the jury:

“Omega Flex is free to point out the purported weaknesses in the Farm Bureau experts’ opinions on cross-examination, and Farm Bureau is free to do the same while cross-examining Omega Flex’s expert.”

Genuine Dispute

Finally, it should come as no surprise at this point that the court held that it was for the jury to resolve the conflicting expert claims on the alleged defectiveness of CSST:

“Upon consideration, the Court finds that Farm Bureau, through its retained experts’ reports, presents minimally sufficient evidence to create a genuine dispute of material fact as to whether the CSST was defective. Here, as with Omega Flex’s causation-based arguments, the Court is not in a position to weigh the parties’ competing expert testimony.”

After issuing this ruling, the court ordered the parties to meet in a settlement conference to try to resolve the matter. This conference was scheduled for July 19. The case has now been closed, so the parties presumably reached an amicable settlement.