Fuel Piping; Gas Piping; Fuel Oil Piping - Weil-McLain 4 Series Manual

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Fuel Piping

1

Gas Piping

1 Consider these factors when sizing the gas piping:
• Diameter and length of the gas supply piping
• Number of fittings.
• Maximum gas consumption (including any
2
possible future expansion)
• Allowable loss in gas pressure from the gas
meter outlet to the boiler
• Apply recognized engineering practices to size
the piping
2 See the burner manual and material list for the
3
minimum inlet natural gas pressure required at
the manual main shut-off valve
3 Pipe dope must be resistant to corrosion by
liquefied petroleum gases Apply pipe dope
sparingly and only to the male threads of pipe joints
4 A ground joint union must be installed in the
4
piping to provide for servicing The supply
piping must include a manual shut-off valve and
sediment trap See Figure 42
5 Piping must be supported by hangers, not by the
burner or its accessories
6 Purge all air from the supply piping
7 All gas piping must be tested for leaks after
5
installation; use soap suds mixture only

Fuel Oil Piping

DANGER
!
Fire Hazard – DO NOT use soldered fittings when
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installing fuel oil piping: No safe repair can be made.
WARNING
!
Oil flow must be prevented in case of oil line
breakage. Failure to comply can cause fuel
leakage or fire, which can result in severe personal
injury, death, or substantial property damage.
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CAUTION
!
Do not install an oil filter outside or close to an
outside wall.
1 Prevent oil flow in case of oil line breakage.
8
a Use an anti-siphon device when any part of the
oil tank is above burner level
b Use a check valve in the suction line on the
burner side of the manual shut-off valve
50
sTeam series
94
Figure 42 Gas supply piping
nearest the tank when the top of the fuel oil
tank is below burner level
2 A two-pipe fuel oil piping system is required for all
installations
3 Supply and return lines must enter the tank from the
top, extending within 4"-6" from the tank bottom
4 Install the oil filter. Use an oil filter sized for the
fuel pump suction gear capacity
5 Use continuous copper tubing to reduce possible
piping leaks and ensure a reliable seal when oil
piping is buried
6 Use flare fittings, not compression fittings.
7 Pipe dope must be resistant to corrosion of fuel
oil Apply pipe dope sparingly and only to the
male threads of pipe joints
8 Supply and return piping should be sized to
design conditions, but not less than 50" outer
diameter continuous copper tubing
9 An auxiliary fuel oil pump is recommended when
suction line lift exceeds 12 feet
10 Install swing joints so they will tighten as the
buried tank settles to prevent fuel line breakage
11 Where iron pipe is required by local codes, make
swing joints with nipples and elbows several
inches long on both suction and return lines;
locate close to the tank
12 Install a manual shut-off valve in the suction line
piping near the burner and where piping enters
the building from the outside tank
13 Pitch the suction line piping toward the fuel tank
14 Provide a tee and plug at the highest point in the
suction line to release air and aid in priming
boiler manual
4
Manual main shut off gas valve
(when required)
Ground joint union
(when required)
To burner gas train inlet
Nipple
Cap
220229
550-100-157/0523