External excess flow check valves should be replaced with internal ones
Chief Controller of Explosives of the Petroleum and Explosives Safety Organisation, Government of India, T.R. Thomas, has issued an order (dated April 16, 2013) instructing owners of vehicles transporting bulk LPG and other flammable, toxic or corrosive compressed gases on roads to replace the existing external excess flow check valves in their trucks with internal excess flow check valves.
The recommendation was made after studying the cause of accidents in which the existing external valve was damaged, resulting in leakage of tonnes of LPG before an explosion.
The order was issued to avoid accidents involving bullet LPG tankers that resulted in heavy loss of life and property in Kollam (August 2009) and Kannur (August 2012) in Kerala and Mangalore in Karnataka (April 2013).
The order also cited that in some cases the thread in the external valve was damaged when repair and maintenance works were carried out, which resulted in leakage. It made the replacement mandatory for bulk LPG tankers for their annual explosive licence to be renewed, with immediate effect.
Secretary of Southern Region Bulk LPG Transport Operators Association N.R. Karthik told The Hindu that the Association that operated all the bulk LPG tankers in South India welcomed the order.
He said that the excess flow check valves in trucks were fitted below the tanks loaded with 18 tonnes of LPG and above the valves through which LPG was unloaded at the bottling plants.
“These valves operate with a spring stop leakage of LPG when the vehicle is involved in an accident. In some cases (including the recent incidents), the valves are sheered away due to which the LPG leaked uncontrollably. LPG, which is highly inflammable, spreads very fast on the ground as it is heavier than air. A small friction or spark results in mass destruction,” he added.
He said that the replacement could prevent leakage even if the external value was destroyed in an accident. According to him, the replacement would cost around Rs. 50,000 to Rs. 60,000 for a truck.
The Association requested the oil companies, Indian Oil, Bharat Petroleum Corporation and Hindustan Petroleum Corporation, for which they are operating trucks on contract basis to compensate the expense incurred for the replacement. “We want to implement safety norms for the benefit of the public and our members, but cannot meet such expenses from our pockets as we are operating at a very nominal tariff,” Mr. Karthik added.
Bulk LPG operator S. Subramanian said that there were a host of other factors that resulted in accidents involving LPG tankers, which included poor road engineering.
“All safety aspects must be taken into consideration and should be given equal importance as replacing valves alone cannot put an end to such disastrous accidents,” he said.