I have a customer that has a generator on their roof. The has supply has been taken off existing black iron gas pipe and run with cast to the black iron drip leg connection on generator. What are the bonding requirements. Can I bond with grounding clamps and bonding wire from roof top piping to drip leg piping or do I have to bond from brass gas tight connection at generator all the way back to the electrical panel.? I have my gas tite cert but can't find the book. And to be honest hardly ever work with the stuff as I'm not a huge fan
I assume you meant this;
"...taken off existing black iron gas pipe and run with cast CSST to the black iron drip leg connection on generator..."?
You don't need to run a bond across the CSST, it is stainless and conductive. Generally the natural gas piping system only needs a single bond from a rigid pipe location to the electrical system ground. As this is a commercial application you might be best to consult with an electrical contractor as to any possible additional requirements.
Here is a link to Gastite Technical Bulletin #TB2014-01:
https://www.gastite.com/downloads/pdfs/Direct-bonding_TB2014-01.pdf