Weld Nipple Coupling Set

The weld nipple coupling set consists of a body with a 24° cone, a nut, and an O-ring weld nipple that is butt-welded to the tube end. The tube is welded to the weld nipple, the weld nipple seats in the cone of the body, and the O-ring seals when the nut is tightened. This creates a connection point in an otherwise fully welded line that can be opened when needed without cutting a weld.

It is used on large-diameter and heavy-wall tubes, on lines where bite-type ferrule fittings are not suitable, in ship hydraulic piping built at shipyards, in rolling mill and press hydraulics, on fixed lines on offshore platforms, and on pressurized auxiliary lines at chemical plants.

• The bore and weld bevel of the weld nipple must match the tube OD and wall thickness.
• The O-ring must always be removed before welding and refitted once the part has cooled; welding heat damages the elastomer.
• Choosing 316L for welded connections reduces the risk of intergranular corrosion in the weld zone.

Installation note: After welding, remove the oxide layer (heat tint) formed on the inner and outer surfaces, and flush the line to clear weld residue before putting it into service.