Oil supply connections at manufactured home sites, where provided from a centralized oil distribution system, shall be located and arranged to permit attachment to a manufactured home utilizing the stand. [NFPA 501A:18.104.22.168] The installation of such facilities shall comply with the following requirements:
- The main distribution pipeline shall be permitted to be connected to a tank or tanks having an aggregate capacity not exceeding 20000 gallons (75708 L) at a point below the liquid level.
- Where this piping is so connected, a readily accessible internal or external shutoff valve shall be installed in the piping as close as practicable to the tank.
- If external and aboveground, the shutoff valve and its tank connections shall be made of steel.
- Connections between the tank(s) and the main pipeline shall be made with double swing joints or flexible connectors, or shall otherwise be arranged to permit the tank(s) to settle without damaging the system.
- If located aboveground, the connections specified in Section E403.13(4) shall be located within the diked area.
- A readily accessible and identified manual shutoff valve shall be installed either inside or outside of the structure in each branch supply pipeline that enters a building, mobile home, travel trailer, or other structure. If outside, the valve shall be protected from weather and damage. If inside, the valve shall be located directly adjacent to the point at which the supply line enters the structure.
- A device shall be provided in the supply line at or ahead of the point where it enters the interior of the structure that will automatically shut off the oil supply, if the supply line between this device and the appliance is broken. This device shall be located on the appliance side of the manual shutoff valve required in Section E403.13(6) and shall be solidly supported and protected from damage.
- Means shall be provided to limit the oil pressure at the appliance inlet to a maximum gauge pressure of 3 pounds-force per square inch gauge (psig) (21 kPa). If a pressure-reducing valve is used, it shall be a type approved for the service.
A device shall be provided that will automatically shut
off the oil supply to the appliance if the oil pressure at
the appliance inlet exceeds a gauge pressure of 8 psig (55
kPa). This device shall not be required under either of the following conditions:
- Where the distribution system is supplied from a gravity tank and the maximum hydrostatic head of oil in the tank is such that the oil pressure at the appliance inlet will not exceed a gauge pressure of 8 psig (55 kPa).
- Where a means is provided to automatically shut off the oil supply if the pressure-regulating device provided in accordance with Section E403.13(8) fails to regulate the pressure as required.
- Only appliances equipped with primary safety controls specifically listed for the appliance shall be connected to a centralized oil distribution system. [NFPA 31:9.2.10 - 9.2.15]