Bradford White TW4-75S-76B-3N - Manual (Page 26)

26
Gas Connections
The gas supply lines must meet all requirements of the National Fuel Gas Code
(ANSI Z223.1-Latest Edition), or in Canada CAN/CGA B149.1 Natural Gas
Installation Code (Latest Edition) or CAN/CGA B149.2 Propane Installation
Code (Latest Edition).
The minimum permissible gas supply pressure for the purpose of input
adjustment is 1 inch (0.25 kPa) water column above the operating manifold
pressure. See the rating plate and gas valve for the manifold pressure and gas
type. The maximum permissible gas supply pressure is 14 inches (3.5 kPa)
water column for natural gas and liquefied petroleum gases/propane gas.
1. Connect this water heater only to the type of gas (Natural or Propane gas)
as shown on the rating plate. Use clean black iron pipe or equivalent
material approved by local codes and ordinances. (Dirt and scale from the
pipe can enter the gas valve and cause it to malfunction). The inlet gas
line must have a minimum length of 3 inches (7.6 cm) drip leg (sediment
trap) installed as close to the water heater’s gas valve as possible. A
ground joint union must be installed as close to the water heater as
possible in the gas supply line feeding the water heater to permit servicing
of the water heater. Compounds used on the threaded joints of the gas
piping must be resistant to the action of liquefied petroleum gases/propane
gas. DO NOT apply pipe dope to the gas valve inlet and make certain that
no pipe dope has become lodged in the inlet screen of the gas valve.
Extreme care must be taken to ensure no pipe dope enters the gas valve.
Avoid excessive torque when tightening the gas supply line to the gas
valve. Excessive torque may result in cracking of the gas valve housing
and could create a gas leak. The suggested maximum torque is 31.5 ft.
lbs. (4.4 kg-m).
2. This water heater and its gas connection must be leak tested before
placing the water heater in operation. Check for gas leaks with a soap and
water solution and a brush or a commercial leak detector fluid. NEVER
USE A MATCH OR OPEN FLAME FOR TESTING!
WARNING
The manufacturer of this water heater will not be liable for any damage or
injury caused as a result of a cracked gas inlet as a result of excessive
torque.
CAUTION
The water heater and individual shutoff valve must be disconnected from the
gas supply piping system during any pressure testing of the system at test
pressures in excess of 1/2 psi (3.5 kPa). The water heater must be isolated
from the gas supply piping system by closing its manual shutoff valve during
any pressure testing of the gas supply system at test pressures equal to or
less than 1/2 psi (3.5 kPa). The supply line must be capped when not
connected to the water heater.