Download Standard Bus Procurement Guidelines

Standard Bus Procurement Guidelines
Flexible fuel and oil lines shall be kept at a minimum and shall be as short as practicable.
Flexible lines shall be routed or shielded so that failure of a line shall not allow fuel or oil to
spray or drain onto any component operable above the autoignition temperature of the fluid.
Flexible lines shall be Teflon hoses with braided stainless steel jackets except in applications
where premium hoses are required and shall have standard SAE or JIC brass or steel, factory
crimped, swivel, end fittings. Flexible hoses and fluid lines shall not touch one another, or any
part of the bus.
Hydraulic lines of the same size and with the same fittings as those on other piping systems of
the bus, but not interchangeable, shall be tagged or marked for use on the hydraulic system only.
The fuel lines forward of the engine bulkhead shall be in conformance to SAE Standard J1149
Type 1 for copper tubing, SAE Standard J526 for welded steel tubing, or SAE Standard J844 for
nylon tubing color coded orange.
Charge air pipework and fittings shall be designed to minimize air restrictions and leaks.
Pipework shall be as short as possible and the number of bends minimized. The bend radii
should be maximized to meet the pressure drop and temperature rise requirements of the engine
manufacturers. The cross section of all charge air pipework shall not be less than the cross
section of the intake manifold inlet. Any changes in pipework diameter shall be gradual to
ensure a smooth passage of air and to minimize restrictions. Pipework shall be routed away
from exhaust manifolds and other heat sources, and insulated or shielded as required to meet the
pressure drop and temperature rise requirements of the engine, transmission or other component
manufacturer.
Charge air pipework shall be seamless, constructed of either stainless steel or anodized
aluminum. Pipework between the air filter and turbocharger inlet may be constructed of
fiberglass. Connections between all charge air pipework sections shall be sealed with a short
section of reinforced hose and stainless steel, constant tension clamps that provide a complete
360 seal.
5.2.2.3
5.2.2.3.1
FUEL SYSTEM
Fuel Tank(s)
The fuel tank(s) shall be securely mounted to the bus to prevent movement during bus
maneuvers, but shall be capable of being removed and reinstalled by a 2M mechanic for
cleaning or replacement in 2.5 hours or less. The capacity of the fuel tank(s) shall be a minimum
of 125 gallons. The fuel tank(s) shall be equipped with an external, hex head, brass drain plug.
It shall be at least a 3/8-inch size and shall be located at the lowest point of the tank(s). The fuel
tank(s) shall have an inspection plate or easily removable filler neck to permit cleaning and
inspection of the tank(s) without removal from the bus. The tank(s) shall be baffled internally to
prevent fuel sloshing noise regardless of fill level. The baffles or fuel pickup location shall
assure continuous full power operation on a 6 percent upgrade for 15 minutes starting with no
Technical Specifications
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1/22/08