In using the term “gas train”, it is not in reference to the large LNG plants which produce liquefied natural gas (LNG) for export and shipment.
For the purposes of this narrative, the term “gas train” refers to the intake assembly on stationary gas turbines and gas ignition, internal combustion engines. The “gas train” controls the supply of gas to the turbine or engine. Gas trains are also found on burners, boilers, ovens and similar equipment.
What is a gas train? The gas train typically comprises a combination of isolation valve, filter, let-down regulator, over-pressure relief, vents, and shut-off valves. The function of the gas train is to automatically regulate the flow of gas to the turbine or engine and to safely shut off the gas.
In Australia, there are special safety requirements required for stationary, gas fuelled, turbines and engines, which are referred to as “Type B Appliances”. The gas train must meet the requirements for type B approval.
For larger type B appliances, part of the approval process covers the identification and classification of hazardous areas associated with the gas train.
Typical hazardous areas are:
The hazardous areas are assessed and classified in accordance with Australian Standards. Information which needs to be collected for the assessment includes ventilation, properties of the gas, the gas train P&ID, the gas train assembly details and Ex certificates for devices.
Layout and general arrangement drawings are produced which show the proposed location of the gas train in relation to the gas turbine or engine. This allows identification of the electrical equipment which may be within the hazardous area.
The electrical components and installation are designed according to the hazardous area classification.
The completed design forms the basis of the documentation required for approval of the type B appliance by the gas assessor.
BESST has the necessary competency to provide hazardous area assessment and electrical design services, including the assessment of gas trains.