Speed Freeze Technology Singapore at Block 5045 Ang Mo Kio Park 2, #01-577 fabricates pressure vessels to be used for refrigerating system. An accident happened at about 8.30am on 22 May 2002 at the factory when a refrigerant receiver was being pressure tested. To conduct the test, the worker (deceased) was filling the refrigerant receiver with nitrogen in order to build up the pressure inside the receiver. In the process the receiver ruptured. The worker was killed instantly. The blast generated by the rupture damaged part of the false ceiling and punctured a hole of adjoining wall with a neighbouring factory.

The deceased person was a 30-year-old male Malaysian worker.

The accident probably happened when the receiver could not take the built-up in pressure of the nitrogen introduced into it and ruptured. This could be due to one or a combination of the following factors:

• The receiver was not properly designed;
• The receiver was not properly fabricated;
• Welding on the receiver was poor standard;
• The receiver was overpressurised during testing;

Investigation into the accident is continuing.

The refrigerant receiver involved in the accident is a pressure vessel as defined under the Factories Act that requires its owner to obtain prior approval from the Chief Inspector of Factories, Occupational Safety Department before it can be put into use. Other types of other pressure vessels include air receivers, steam receivers and steam boilers. The Act also requires that such pressure vessels be of sound construction, properly maintained and periodically tested by an authorised boiler inspector.

The Ministry would like to remind owners of such pressure vessels to obtain approval before they are put into use. Approval should also be sought if a pressure vessel is to be fabricated locally. The Ministry would also like to remind owners of pressure vessels not to use gas for pressure testing. Low compression substances (such as water) should be used for such tests.