220.127.116.11 Vapor discharge outlet. Provision shall be made for discharging to atmosphere
vapors from the vapor recovery system when vapor collection facilities are not available. The
location of the outlet shall be on the top of the tank, remote from the driver's loading area, and
isolated from the engine exhaust.
3.5.13 Bottom loading system. The tank shall be capable of being bottom loaded at a
rate of not less than 600 gpm. To provide bottom loading capability, the tank shall be furnished
with an automatic vent valve (see 18.104.22.168), a level-sensor controlled automatic flow control
valve, and a bottom loading adapter with check valve. The system, including the automatic vent,
shall be designed failsafe to prevent damage to the truck or any of its components if the bottom
loading system malfunctions or is operated incorrectly. The system shall comply with
paragraph 4-14.3 of NFPA No. 407.
22.214.171.124 Inlet manifold. The bottom loading inlet manifold shall extend from the bottom
loading adapter to the automatic flow control valve in the bottom of the tank. The complete inlet
manifold system shall be sized to meet the required system filling rates and pressures.
126.96.36.199 Automatic flow control valve. An automatic flow control valve which serves as
a combination bottom loading and emergency valve shall control the flow of fuel into the tank
during bottom loading. The control valve shall be level-sensor controlled to shut off intake flow
when the tank has reached its rated fluid capacity. A remotely operated manual control shall also
be provided to open or close the valve. The automatic flow control valve operation shall be in
simultaneous actuation with the automatic vent (see 188.8.131.52). The design of the control valve
shall be in accordance with the emergency flow control type valve described in 49 CFR,
section 178.341-5 of MC-306, for assurance against accidental escape of contents. A deflector,
in accordance with paragraph 4-14.3.8 of NFPA No. 407, shall be mounted in the tank over the
flow control valve in order to prevent the fuel from spraying unrestrictedly into the tank.
184.108.40.206.1 Tank level-sensor control. The level control shall automatically shut off the
automatic flow control valve when the tank is filled to its rated capacity. The level control unit
shall be a hydraulic jet type sensing device utilizing line fuel pressure with a jet stream directed
to a receiver. The level control shall have no moving parts but shall be adjustable to various
heights from the manhole(s). A means shall be provided to precheck the level control system to
determine if it is functioning properly. The level-sensing device shall be failsafe in case of line
breakage or leakage. The level control system shall operate properly within the designed system
pressure range and shall operate with the type of fuel specified without causing undue corrosion
or deterioration of the equipment. The level sensor and any associated valves shall be free of all
liquids with a freezing point above minus 50 °F.