An explosion that blew a cooker hob off its mountings in a Birkirkara home five years ago was not caused by an overfilled gas cylinder but a faulty regulator, a magistrate has ruled.

Magistrate Consuelo Scerri Herrera was informed that investigations carried out by court-appointed experts determined that it was the faulty regulator that caused the blast at the residence of George and Marcelle Montanaro on July 1, 2010.

The Montanaros filed a court case against Enemalta and Liquigas Malta demanding compensation for the damage sustained to their hob when it exploded early in the morning as Ms Montanaro was about to start preparing her children’s breakfast.

Mr Montanaro told the court that, when Liquigas technicians went to his house, they found that the gas pressure in the cylinder was six bar, twice what it should have been, indicating that it was this that had caused the hob to explode.

Mr Montanaro said the technicians had admitted this was not the first time such a thing had happened.

However, Liquigas technician Brian Schembri testified that a six bar pressure was “normal” for a cylinder and that, although he had noted in writing that the cylinder in question had been overfilled, this was not the case. Moreover, he also admitted having failed to take into consideration the environment where the cylinder was held: outside, in the sun.

Gas cylinders are designed to withstand pressure of up to 65 bar.

He had based his findings on experience and beliefs rather than on scientific evidence

The court heard that Mr Schembri was “inexperienced” and had not carried out the proper tests to determine the cause of the explosion.

An investigation by court-appointed experts showed that the regulator used by the Montanaros was seriously damaged. Regulators normally need replacement after between five and 10 years.

In this case, the regulator was 12 years old, reducing its potential to withstand pressure.

The experts testified that, when tested, the release was always in vapour form, clearly indicating that the cylinder was not overfilled. Had the cylinder been overfilled, liquefied petroleum gas would have been released in liquid form.

The regulator used by Mr Montanaro was leaking. This leakage occurred on the roof before he changed the regulator for another one he had in the garage. In her consideration, Magistrate Scerri Herrera noted that the regulator in question was manufactured in 1997.

Court-appointed expert Victor Bonello said it was the excess pressure that ruined the regulator but his conclusions were shot down by other experts also appointed by the court. Engineers Ryan Fava, Raymond Vassallo and Fabio Stivala concluded gas had accumulated under the hob, causing it to explode because of a faulty regulator.

The magistrate said that Mr Bonello had based his findings on “experience and beliefs” rather than on scientific evidence.

As a result, she said the report could not be given weight. Based on the conclusions of the other experts, she dismissed the case, saying no compensation was due to the Montanaros.