MOTORISTS and mechanics who exchange or replace parts of engines fuelled by compressed natural gas (CNG) could be playing with fire, the government has warned.

The warning follows gas explosions reportedly involving CNG-powered vehicles that the Ministry of Energy says were caused by faulty maintenance.

“Equipment installed in CNG vehicles shouldn’t be removed, repaired or replaced without proper safeguards. This is illegal and could be dangerous,” a ministry spokesperson told participants in an information briefing held by the Yangon Traffic Rules Enforcement Supervisory Committee at the International Business Centre last month.

But according to the ministry presentation, CNG cylinders offer reduced risk of a leak, and can last from 15 to 30 years.

“The ministry allows the use of a CNG cylinder at a working pressure of 3000 PSI but forbids the installation of liquefied petroleum gas cylinders for propane, butane, nitrogen and argon,” he said, adding that the recent blasts were not caused by faulty CNG cylinders, but by faulty installation of extra cylinders.

“Owners who suspect a problem of this kind should check with CNG mechanical experts,” he said, and should comply with instructions for use issued by the ministry.

All vehicles converted to CNG should be checked at least annually to ensure the cylinder and other parts are in good working order, he said.

CNG is considered less dangerous than liquid fuels because it diffuses rapidly in the air. Cylinders are fitted with safety valves in the event of overfilling, and any leak is signalled by an automated voice warning. All equipment used in converting petrol- and diesel-powered vehicles to CNG must be standard and recognised by the ministry, and conversion must be carried out by one of the 35 companies authorised by the ministry.

The Ministry of Energy has expanded the use of CNG since 2006 to cut down on air pollution, save fuel, make more effective use of locally produced gas, and speed the flow of passengers and commodities.

According to the Ministry of Energy, there are some 23,000 vehicles in Myanmar converted to use CNG. But the Yangon Traffic Rules Enforcement Supervisory Committee has suspended conversions for the last two months.

Daily CNG sales at the country’s 37 CNG filling stations has risen to more than 15 million cubic feet from 11 million last year, it said.