The best fuel choice for a truck depends on the duty cycle of the vehicle. Trucks that do lower mileages or that return to a base frequently will often be suited for CNG, while heavy duty trucks that do higher mileages might be more suited for LNG.
The six main component parts fitted to the vehicle are:
a) The filler connection which incorporates a non return valve.
b) The NGV storage cylinder together with a cylinder valve which incorporates a fusible plug.
c) A first stage regulator to reduce the pressure from 20MPa to approximately 0.7MPa.
d) A vacuum operated NGV fuel lock-off valve which prevents the flow of NGV fuel when the engine stops.
e) A second stage regulator which further reduces the pressure.
f) An air/gas mixer that measures air flow and meters the flow of gas into the engine.
NGV fuel cylinders
The NGV fuel cylinder is a tested pressure vessel which is designed and constructed in accordance with strict Malaysian Standards. During manufacture it is subjected to controlled heat treatment. Therefore it is imperative that no welding, soldering, brazing or heating of the cylinder takes place after the manufacture of the vessel.
All cylinders must be securely and permanently affixed and must be capable of being filled in that position.
Some NGV fuel cylinders are constructed using fibreglass reinforced plastic (FRP) wrapped around the outside of the steel cylinder. This type of construction allows for a lighter NGV cylinder but it is important that the FRP layer is not damaged as this provides part of the cylinder’s strength.
All-steel cylinders and FRP reinforced steel cylinders must be inspected periodically. All-steel cylinders may continue to be used for as long as these inspections show that the cylinder remains sound, however FRP wrapped steel cylinders must be replaced after 15 years of use.
