Installation Guide

HOME-FLEX CSST 39
Electrical Bonding
Bonding Guidelines
Direct bonding is required for gas piping systems incorporating standard (yellow) CSST
whether or not the connected gas equipment is electrically powered. This requirement is for
single-family and multi-family buildings and required by the 2009 and later editions of the
National Fuel Gas Code, the International Fuel Gas Code and the Uniform Plumbing Code. A
person knowledgeable in electrical system design, the local electrical code and these require-
ments should specify the bonding for commercial applications.
CSST installed inside or attached to a building or structure shall be electrically continuous
and direct-bonded to the electrical ground system of the premises in which it is installed.
The gas piping system shall be considered to be direct-bonded when installed in accordance
with the following:
The bonding conductor is permanently and directly connected to the electrical service
equipment enclosure, the grounded conductor at the electrical service, the grounding elec-
trode conductor, or to one or more of the grounding electrodes used. When an additional
grounding electrode(s) is used for the gas service, it shall be bonded to the electrical service
grounding electrode system or, where provided, the lightning protection grounding system.
For single and multi-family structures a single bond connection shall be made on an acces-
sible rigid piping component or CSST tting located downstream of the utility gas meter or
second-stage LP regulator. The bonding clamp attachment point may be at any location with-
in the gas piping system. However, the shortest practical bonding wire length will improve
the eectiveness of the direct-bond. The corrugated stainless steel tubing portion of the gas
piping system shall not be used as the point of attachment of the bonding clamp under any
circumstances. (Figure 4.30 and Figure 4.31)
The bonding conductor shall be no smaller than a 6 AWG copper wire or equivalent. The
bonding conductor shall be installed and protected in accordance with the National Electri-
cal Code, NFPA 70, (NEC) and Canadian Electrical Code CSA-C22.1 (CEC). Bonding/grounding
clamps shall be installed in accordance with its listing per UL 467 and shall make metal-to-met-
al contact with a rigid pipe component or CSST tting. This direct-bond is in addition to any
other bonding requirements as specied by local codes for ground fault protection.
The 2018 edition of the National Fuel Gas Code, International Fuel Gas Code, and Uniform
Plumbing Code limits the length of the bonding conductor to 75-ft. When there are no local
code requirements for the length of this conductor refer to the NEC / CEC for guidance
regarding the permissible length of the bonding conductor.
Black Iron Tee
Bonding Clamp (UL 467)
Heavy Gauge Bonding Wire to Electrical Grounding System
(minimum 6 AWG, maximum length of 75')
Note: Remove any paint on pipe
surface under bonding clamp
Figure 4.30 Bonding Connection to Brass Fitting
Brass HOME-FLEX® Fitting
Figure 4.31 Bonding Connection to Rigid Black Iron Pipe
Black Iron Pipe Component
Heavy Gauge Bonding Wire to
Electrical Grounding System
(minimum 6 AWG, maximum
length of 75')
Note: Remove any paint on pipe surface under bonding clamp
Bonding Clamp (UL 467)