Section 279(2) in The West Bengal Motor Vehicles Rules, 1989
(2)No generator and no pipe between the generator and the gas filters shall be so placed that any part of the generator of such pipe is within a distance of less than -(a)61 centimetres from any part of the petrol tank;(b)122 centimetres from the filling point or office or of the petrol tank :Provided that in the case of a transport vehicle other than a public service vehicle, the generator may be at a distance of less than 61 centimetres from any part of the petrol tank, but there shall be a distance of less than 20 centimetres between any part of the generator or of any pipe connecting the generator or the gas filter and any part of the petrol tank :Provided further that when any part of the generator or pipe as aforesaid is at a distance of less than 61 centimetres from any part of the petrol tank, that part of the generator and pipe shall be inserted lated from that part of the petrol tank by the interposition of the insulating material and the clearance specified in rule 278 of these rules.