AT CNG FILLING STATION
When CNG buses are filled at filling stations, normal precautionary measures are implemented according to Indian and also international standards. But there is scope for improving the layout of the existing gas filling stations to ensure better approachability and safety.
As of now, type approval certificate has been given to CNG vehicles fitted only with nozzles meeting Indian Standards. These are prone to frequent o-ring failures - an item in nozzles. We are informed that they occur on an average about once every 20 fills. This failure not only interrupts fueling and requires replacement of the o-ring; it also creates a fire hazard due to the release of a significant amount of high-pressure gas. Standardizing of all vehicle-refueling receptacles on the standard would reduce fuelling time requirements and queues, and make possible more efficient use of existing compression capacity.
NOZZELS & SAFETY
As of today, the cylinders meet the common standards set for all high pressure gas cylinders from oxygen to hydrogen by the Bureau of Indian Standards and approved by the Chief of Comptroller of Explosives. But these standards do not take into account on-board high- pressure gas cylinders mounted on moving vehicles. International standards have been specially set for on-board cylinders. There is a need for enforcement of these safety regulations as well.