Ermeto tube to weld nipple, types AS and WAS can be assembled in any Ermeto tube fitting. Ermeto tube to weld fittings are available in steel, stainless steel and all sizes from 6 - 38/42 in the light and heavy series. The Ermeto tube to weld nipple is welded to the tube end without the O-ring. Assembling beforehand a retaining nut with the right size and orientation should not be forgotten. Special guidelines and regulations may apply to the pre-handling of the tube-end, the welding procedure, welding personnel qualifications, post-processing and testing and documentation of the weld connection.