Abstract: An improved apparatus for producing a flexible plastic corrugated tubing includes a pair of relatively short, slender rotating mandrels extending substantially parallel to one another and separated along a vertical plane and around which a continuous ribbon of molten plastic is spirally wrapped to form the tubing. In another embodiment, a plurality of elongated rollers spaced apart axially form a tunnel therebetween through which the tubing is directed from the mandrel at least one of the rollers being rotatably driven to drive the tubing through the tunnel.

Abstract: An assembly for diffusing gas in a humidifier comprises a base plate having a wall extending around its periphery, a diffuser sheet comprising a substantially gas impermeable membrane having a plurality of perforations and a member for directing gas to be humidified into a gas receiving chamber defined between the diffuser sheet and base plate. In a humidifier, the assembly is submerged in water and gas travels through the gas directing member, into the gas receiving chamber and outwardly through the perforations in the diffuser sheet into the water where it is humidified and exits from the humidifier.