Corrugated Stainless Steel Tubing Issue

We recently received this letter from Jim Murphy regarding the issue of using Corrugated Steel Tubing in the distribution of natural and propane gas. Please review Jim's overview and comments and feel free to 'Post a Comment' back to this newsletter with your thoughts. We would love to hear your feedback.

Letter from Jim:

Mr. Holt I don't know if you have covered this issue previously, but there is a lot of controversy in our area regarding the use of Corrugated Stainless Steel Tubing used for distribution of natural gas and propane gas in residential and other structures.

The issue is the opportunity for fire and explosion caused by lightning strikes. The manufacturer claims problems are caused by lack of proper bonding but it appears that bonding is not the issue. The stainless steel is often damaged by the lightning flashing over onto the tubing from other metal lightning conducting paths. A low impedance path to ground does not in any way save the CSST from damage.

The electrical inspectors in our area say the bonding in accordance with NEC is accomplished via the ground wire or bond run with the conductors to an air handler, water heater, etc. I understand the NEC does not address this specifically.

The CSST manufacturer calls for the tubing to have a separate #6 bond run to the gas distribution manifold.

The issue becomes one of damned if you do or damned if you don't. There have been lawsuits resulting from fires and explosions even in structures that have been bonded in accordance with the manufacturers instructions. The current position taken by some is if the gas pipe installer uses CSST, then it is his responsibility as the installer to provide for any additional bonding to satisfy the supposed safety requirement of the manufacturer.

It would appear that the use of CSST should be outlawed. I started in the trades years ago hand threading black iron pipe for gas service to residences. Over 40 years later, there is still no problem or complaint from lightning damage.

My company has advised our customers that this product is to be considered faulty and we will accept no responsibility for it's use. We point out the bonding block we install exterior to the house and adjacent to the service entrance as their destination if they want to supply further bonding for the CSST.

We look forward to seeing your comments on this matter.

James Murphy
Murphy Electric, Inc.
Murphelec@aol.com
(302) 644-0404

Click here for our follow up story: Corrugated Stainless Steel Tubing for Fuel Gas Distribution in Buildings and Concerns Over Lightning Strikes (our October 31, 2012 newsletter)