Section 1090.1565 - Requirements related to dispensing liquefied petroleum gas(a) Except for pumps dedicated to heavy-duty vehicles, any pump installation used for dispensing liquefied petroleum gas into motor vehicles must have a nozzle that has no greater than 2.0 cm3 dead space from which liquefied petroleum gas will be released when the nozzle disconnects from the vehicle.(b) Determine the volume of the nozzle cavity using calculations based on the geometric shape of the nozzle, with an assumed flat surface where the nozzle face seals against the vehicle.