Red and Blue Coloured Welding Hose Pipe is used for other non-combustible gases. The Hose Pipe has the feature that the red is used for acetylene application while blue hose is used for oxygen and other non-combustible gases. The Red and Blue Coloured Welding Hose Pipe is offered in sizes from 6 to 10 mm and wall thickness from 3 to 3.5 mm.