Variation of NGK GLow Plugs:
NGK Glow Plug Types
There are many types of glow plugs available to cater for the wide variation of engine types and their control systems. NGK glow plugs can be broadly classified into two groups; the metal glow plug in which the coil is enclosed in a tube made of heat resistant metal and the ceramic glow plug which has its heating coil enclosed in a ceramic material.- NGK Glow Plug Features
Metal Glow Plug features(Sheathed type)
The heating coil and regulating coil(where applicable) are enclosed in a tube made from heat resistant alloy and magnesium oxide power is packed between the coil and tube. The coil is therefore not directly exposed to the combustion process and the shock waves produced by the rapid expansion of the gases. Because of the protection afforded by hte tube, carbon produced by the combustion process cannot build up on the heating coil and cause a short-circuit.
