Series Premier VS-VH
Page 43
LT135 Dec 2019
Figure 38: Outside Combustion Air Detail
4. Gas Supply System
General Requirements
Supply Lines
The Gas Supply Meter and the Supply Service must be sufficiently large to supply gas to the total building gas load
including the heating equipment. Additionally, the gas distribution piping must be designed according to local and
national ordinances. Generally, systems designed with a maximum ½” W.C. total pressure drop (low pressure)
meet this requirement.
Gas supply pipe sizing must be in accordance with the National Fuel Gas Code, ANSI Z223.1 (NFPA 54) in the
USA and CSA B149.1 and B149.2 Installation Codes in Canada.
A 1/8” NPT plugged tap must be installed in the Gas Line connection immediately upstream of the Burner farthest
from the Gas Supply Meter to allow checking of system gas pressure.
A Gas Shut-off Valve must be installed parallel to EACH Burner Gas Inlet connection.
Before connecting Burners to the Gas Supply System, verify that high pressure testing of the Gas System
has been completed. Burners must be isolated from any pressure testing in excess of ½ psi (3.5 kPa).
Failure to comply may expose the Burner components to damage due to high pressure, requiring replacement of
key components.
