csst and lightning - InspectionNews

Victor DaGraca · #1 (**permalink**) 10-15-2007, 12:17 PM

I don't know if this is the proper area to post this, but, here ya go...

This morning, GMA ran a story about a potentially deadly problem covering about 2 million homes in The US.
The problem stems from the usage of a "new" type of gas line being used called Corrugated Stainless Steel Tubing, or CSST, which is used to bring Propane into the home for use in Fireplaces, water heaters, stoves, dryers , furnaces and any other appliance that uses propane gas.
The problem as reported is the thin wall construction and improper grounding of the pipe. The energy released by an indirect lightning strike can easily rupture the pipe, creating a leak, and an explosive situation.
This Newspaper article gives you some of the story.

A class action lawsuit has been settled without the manufacturer admitting culpability.However, more lawsuits are sure to follow.
The gas pipe in question can be identified by its yellow plastic covering and the manufacturers name (WardFlex)imprinted on it,

Bruce King · #2 (**permalink**) 10-15-2007, 01:18 PM

This issue has been up in the air for some time now.

Charlotte (mecklenburg county) now requires an electrical permit and inspection for proper bonding of CSST. CSST Bonding

Just found this link...

http://www.toolbase.org/pdf/techinv/...ngconcerns.pdf

Gastite is one co. and they require a clamp at the entry point onto the black iron pipe and do not allow and clamping to the actual csst flex.

We need to check each manuf's requirements for exact instructions.

Victor DaGraca · #3 (**permalink**) 10-15-2007, 01:46 PM

"CSST manufacturers have always required that CSST systems be bonded to the electrical system in accordance with the NFGC and the NEC. However, the bonding methods prescribed within these documents are minimum requirements and are designed to protect the consumer against ground-faults from the premise wiring system. Neither code requires protection against lightning strikes "

"
Although the bonding instructions of the six CSST manufacturers currently appear to be different, they all result in the same final installation. Efforts are underway to develop a universal set of installation instructions that will be adopted by all CSST manufacturers. "

"Recently updated CSST manufacturer’s installation instructions now include the requirement to directly bond the CSST system to the electrical system grounding system. The bonding attachment must be near the service entrance to the building and the connection must be made with a 6 AWG copper wire "

Sounds like 6 AWG bonded to grounding conductors is the way to go.
And, the manufacturers have recently upgraded the installation standards.
However, that leaves a lot of installations out there that might fail.

regardless... another item to call out.

Steve D'Gerolamo · #4 (**permalink**) 10-26-2007, 12:55 PM

Is copper distribution of gas required to be grounded like CSST?

wayne soper · #5 (**permalink**) 10-26-2007, 01:35 PM

Victor, I think adding EFV's to the system( excess flow valves) is as, or more important than bonding or grounding because these valves will stop the flow of gas. The two systems instaklled togeather is a good start. ALso the settlement period is over.

Jim Luttrall · #6 (**permalink**) 10-26-2007, 01:55 PM

Steve, ALL metal piping systems are required to be bonded.