Friction drilled spray header

A method of making a spray header, the method comprising the steps of:

• supporting a header pipe in a fixture;
• friction drilling a plurality of mounting openings in an external surface of the header pipe by feeding a friction drilling tool into a side wall of the header pipe, each friction drilled mounting opening being at a desired location of a spray nozzle port, the friction drilling forming an annular extension at each mounting opening that extends seamlessly and radially inwardly from an inner wall of the header pipe with each annular extension being formed unitarily with the header pipe;
• removing excess material from an internal circumferential wall of each mounting opening including in the respective annular extension;
• and
• cold forming internal threads in the internal circumferential wall of each of the mounting openings including in the respective annular extension.

A spray header assembly for discharging a fluid onto a spray target, the spray header comprising:

• a spray header pipe with an elongated tubular side wall with a hollow interior that defines an internal fluid passageway, the header pipe being made of a material;
• the spray header pipe including a plurality of spray nozzle ports, each spray nozzle port including a respective mounting opening that extends through the side wall of the spray header pipe and communicates with the internal fluid passageway;
• each spray nozzle port including a respective annular extension that extends radially inwardly from an inner surface of the side wall into the internal fluid passageway such that each mounting opening extends from an external surface of the side wall through the side wall and through the annular extension to reach the internal fluid passageway, each mounting opening including the corresponding annular extension being internally threaded;
• wherein each annular extension extends seamlessly from the header pipe and is formed unitarily from the material of the header pipe.