Current through Register Vol. 54, No. 45, November 9, 2024
Section 171.21 - Exhaust system(a)General rule. The exhaust pipe, muffler and tailpipe shall be outside the body compartment and securely attached to the chassis with clamps and hangers of a type and installed as recommended by the chassis manufacturer.(b)Tailpipe. The tailpipe shall be constructed of a corrosion-resistant tubing material at least equal in strength and durability to 16 gauge steel tubing.(c)Tailpipe extension. The exhaust system of a school bus powered by a gasoline engine shall discharge to the atmosphere at or within 6 inches forward of the rearmost part of the school bus.(d)Tailpipe extension for school buses using fuels other than gasoline. The exhaust system for a school bus using fuels other than gasoline shall discharge to the atmosphere either at or within 15 inches forward of the rearmost part of the vehicle; or to the rear of all doors or windows designed to be opened, except windows designed to be opened solely as emergency exits.(e)Insulation. The exhaust system on a gasoline powered chassis shall be properly insulated from fuel tank connections by a securely attached metal shield at any point where it is 12 inches or less from the tank or tank connections.(f)Muffler. The muffler shall be constructed of corrosion resistant material.(g)Discharge lines and outlets. The discharge lines and outlets on school buses equipped with compressed or liquefied gas fuel systems shall be installed in accordance with Chapter 175 (relating to vehicle equipment and inspection).(h)Exhaust system hangers. Exhaust systems may be equipped with hangers that permit required movement due to expansion and contraction caused by heat of the exhaust and relative motion between the engine and chassis of a vehicle.(i)Exhaust system and discharge location. Exhaust systems are not permitted to discharge to the atmosphere at a location immediately below the fuel tank or the fuel tank filler pipe. Exhaust systems shall also extend and discharge completely to the outside edge of the vehicle body.(j)Exception. This section does not apply to auxiliary fuel-fired heating systems.The provisions of this §171.21 adopted August 4, 1978, effective 7/1/1979, 8 Pa.B. 2194; amended August 31, 1979, effective 9/1/1979, 9 Pa.B. 2954; amended August 19, 1983, effective 8/20/1983, 13 Pa.B. 2561; readopted December 4, 1987, effective 12/5/1987, 17 Pa.B. 5052; amended September 13, 1996, effective 9/14/1996, 26 Pa.B. 4411; amended November 26, 2003, effictive November 29, 2003, 33 Pa.B. 5817; amended May 20, 2005, effective 5/21/2005, 35 Pa.B. 3039.The provisions of this §171.21 amended under the Vehicle Code, 75 Pa.C.S. §§ 4103, 4551-4553 and 6103.