Crown Boiler FWZ Series, Руководство по установке

Страница: 26 / 56

24
IX Fuel Line Piping
WARNING
• Under no circumstances can copper with sweat style connectors be used.
• Do not use compression fittings.
• Oil piping must be absolutely airtight or leaks or loss of prime may result.
• Some jurisdictions require the use of a fusible shutoff valve at the tank and/or the burner.
In addition, some jurisdictions require the use of a fusible electrical interlock with the
burner circuit. Check your local codes for special requirements.
Fuel line piping design, materials and construction must be in accordance with local building codes, requirements of the local
authority having jurisdiction, and, the latest edition of the Standard for the Installation of Oil-Burning Equipment (ANSI/NFPA
31) in the United States and CSA B139-04 for installation in Canada. Refer also to the instruction manuals provided with the
burner and oil pump.
Depending on the location of the fuel oil storage tank in relation to an oil burner, there are four types of oil piping systems that
may be encountered:
a) ONE-PIPE GRAVITY SYSTEM - Used when a fuel oil storage tank is positioned above an oil burner fuel pump. See
Figure 9.0. A vertical distance from top of the tank to center line of the pump (Dimension ‘H’) over 8 feet will result in a
pump inlet pressure in excess of the 3-psi limit in NFPA-31.
b) ONE-PIPE LIFT SYSTEM (not recommended) - Used when a fuel oil storage tank is located below an oil burner fuel
pump. See Figure 9.1. The vertical distance from bottom of the tank to center line of the pump (Dimension ‘H’) must not
exceed that shown in the pump manufacturer’s instructions. Although all oil piping systems must be airtight, one-pipe lift
systems are particularly susceptible to nuisance lockout problems if the suction line is not completely airtight. A two-pipe
lift system is therefore preferred to a one-pipe lift system.
c) TWO-PIPE GRAVITY SYSTEM (not recommended) - A vertical distance from top of the tank to center line of the pump
(Dimension ‘H’) over 8 feet will result in a pump inlet pressure in excess of the 3-psi limit in NFPA-31. This type of
system should be converted to a one-pipe gravity system, as doing so will result in lower inlet line flow and longer filter
life.
d) TWO-PIPE LIFT SYSTEM - Used when a fuel oil storage tank is located below an oil burner fuel pump suction port.
See Figure 9.3. The vertical distance from bottom of the tank to center line of the pump (Dimension ‘H’) must not
exceed that shown in the pump manufacturer’s instructions. The maximum permissible distance ‘H’ allowed is reduced
by the number of fittings, filters and valves installed in the line.
Once the type of system has been selected, observe the following:
1) Fuel line piping must be airtight. Do not use compression type fittings for tubing connections in fuel line piping. Use only
listed flare type fittings. Cast iron threaded fittings shall not be used.
2) Piping shall be substantially supported and protected against physical damage and corrosion.
3) Refer to supplied oil pump instruction manual for proper connections. On one-pipe systems, ensure that the fuel pump return
port plug is tightened securely.
4) Some fuel pumps, such as the Suntec A and B series, are supplied with a loose bypass plug which must be installed on two-
pipe systems. If such a plug is supplied, install it as shown in the pump manufacturer’s instructions. Do not install this bypass
plug on one-pipe systems as pump seal damage will result.
5) Do not use check valves, especially on gravity feed systems.
6) Do not use Teflon tape for threaded connections. Use a non-hardening thread sealant listed for use with #2 fuel oil .