It is made up of a battery of filling connections, which is employed to connect the gas cylinders. Also, non-return valves are employed to adjoin various sections of the pipeline to the filling manifold. It makes working of the plant safe. The non-return valves are extremely important for the safe operation of the plant and should be periodically examined. The acetylene manifold should be cleaned from time to time to remove rust and scales, (iron rust rushing though the pipeline at high speed could generate a spark and cause fire). The cylinder filling pig tails (flexible hose pipes) must also be cleaned to ensure that they do not burst open during filling operation.