Abstract: In a piercing operation prior to the laser cutting of steel, etc., the development of a technology in which a piercing hole of the intended shape is obtained in a short time, even for a thick cut work. An oxygen gas coaxial to the laser beam applied towards the cut work and a low concentration gas with a low oxygen concentration and major components comprising nitrogen gas, air, or a mixture thereof discharged from an outer gas nozzle disposed so as to surround the outer side of the flow of this oxygen gas is supplied and disposed towards said cut work, and can realize shortening of the time, etc., of the piercing operation time by applying a laser beam to the cut work. In addition, a laser processing nozzle provided with an inner gas nozzle which discharges oxygen gas and an outer gas nozzle which discharges low concentration gas, and a laser cutting apparatus provided with this nozzle is provided.

Abstract: Method for the safety and extension of the operating life of pressure equipment having an internal chamber suitable for containing a process fluid, surrounded by a pressure-resistant body (1) equipped with weep-holes (2), made of a material subject to corrosion by contact with said process fluid operation, coated inside with an anticorrosive lining (4) made up of several elements welded to each other, wherein said lining weldings (3) are completely isolated from contact with the process fluid of the normal operating run, by a coating with adjoining strips (or plates) (10, 10′, 10″, 10′″), of the same material as said lining (4) or other corrosion-resistant material weldable thereto, which are subsequently seal-welded on the edges to said lining (4) and to each other, characterized in that the arrangement and welding of the edges of these strips (10, 10′, 10″, 10′″) are such to create a network of underlying interstices (or meati) (9,11), communicating with each