Internet Version for Reference Only
BRADFORD WHITE
Page 14
Copper Brute B4 Volume Water Heaters Page 15
2.6.10 Thermal Circulation of Hot Water
in Cold Water Supply Lines
Under certain circumstances, thermal circulation
will occur in the cold water pipe supplying the water
to the heating system. This happens in a multi-story
building when the cold water pipe rises from its
connection to the system. To correct the problem, a
check valve in the cold water line supplying the heater
will prevent thermal circulation, and a small expansion
tank will permit heated water to expand without
popping off the relief valve.
2.7 Gas Supply and Piping
2.7.1 General Instructions
Review the following instructions before
continuing the installation.
1. Gas piping installation must be in accordance
with the latest edition of ANSI Z223.1. In
Canada, the installation must be in accordance
with CAN1-B149.1 or .2 and all local codes that
apply.
2. Check the rating plate to make sure the heater
is tted for the type of gas being used. Bradford
White heaters are normally equipped to operate
below a 2000 foot (609 m) altitude. Heaters
equipped to operate at higher altitudes have
appropriate stickers or tags attached.
3. If a gas pressure regulator is required, the
installation must be in accordance with the latest
edition of ANSI Z223. In Canada, the installation
must be in accordance with CAN1-B149.1 or .2
and all local codes that apply.
4. The gures in Table 5 should be used to size the
gas piping from the gas meter to the heater.
5. Install a sediment trap (drip leg) ahead of the
gas controls (see Figure 24 ). Fit the trap with a
threaded cap which can be removed for cleaning.
6. Install a manual gas shutoff valve for service and
safety. Check the local codes.
7. Disconnect the heater and its individual shutoff
valve from the supply gas system during pressure
test of the system at pressures higher than 1/2 psi
(3.4 kPa).
8. Gas supply pressures to the heater are listed in
Table 6.
NOTE: The heater and all other gas appliances
sharing the heater gas supply line must be ring at
maximum capacity to properly measure the inlet
supply pressure. Low gas pressure could indicate
an under-sized gas meter and/or obstructed gas
supply line.
Figure 24. T-Fitting and sediment trap.
9. Do not exceed the maximum inlet gas pressures
specied. Excessive pressure will result in
damage to the heater's gas controls. The
minimum pressures specied is for gas input
adjustment.
10. The correct burner manifold gas pressure is
stamped on the rating plate. The regulator on the
gas valve is preset at the factory, and does not
normally need adjustment.
Distance from Gas Meter or Last Stage Regulator
0-100 feet 100-200 feet 200-300 feet
0-30 m 30-60 m 60-90 m
Boiler Nat. Nat. Nat.
Size in. mm in. mm in. mm
175 1 25 1 32 1 32
250 1 32 1 32 1 38
325 1 32 1 38 1 38
400 1 32 1 38 2 51
Notes:
1. These numbers are for natural gas (0.65 Sp. Gr.) and
are based on inch (13mm) water column pressure
drop. Check supply pressure with a manometer, and
local code requirements for variations. For liqueed
petroleum gas, reduce pipe diameter one size, but
maintain a inch (13mm) minimum diameter.
2. Check supply pressure and local code requirements
before preceding with work.
3. Pipe ttings must be considered when determining gas
pipe sizing.
4. For propane gas: Reduce pipe diameter one size, but
maintain a inch (19mm) minimum diameter.
Table 5. Natural Gas and Propane,
Pipe Size Requirements.
Supply Pressure Natural Gas Propane Gas
Water Column in. mm in. mm
Minimum 6.5 165 11 279
See Rating Plate
Maximum 9 229 14 356
Table 6. Gas Supply Pressure Requirements.
MANUALSHUT-OFF
VALVE
GAS
SUPPLY
INLET T-FITTING
3"(76 mm)
MIN.
UNION
NIPPLE
CAP
TO
BOILER
INLET