The present invention relates to an air conditioner. The air conditioner according to the present embodiment has a refrigeration capacity of 11 kW to 16 kW, inclusive, and uses R32 as a refrigerant circulating therein, and since a refrigerant pipe therein is made of a ductile stainless steel material having 1% or less of a delta-ferrite matrix structure with respect to the grain size area thereof, the refrigerant pipe can maintain strength and hardness as good as or better than those of a copper pipe, while also maintaining good processability.

The present invention relates to an air conditioner. The air conditioner according to the present embodiment has a refrigeration capacity of 7 kW to 11 kW, inclusive, and uses, as a refrigerant, a mixed refrigerant containing 50% or more of R32, and since a refrigerant pipe therein is made of a ductile stainless steel material having 1% or less of a delta-ferrite matrix structure with respect to the grain size area thereof, and includes a suction pipe guiding the suction of the refrigerant into a compressor and having an outer diameter of 15.88 mm, the refrigerant pipe can maintain strength and hardness as good as or better than those of a copper pipe, while also maintaining good processability.

A method of managing a tubular having a seam that exhibits signs of hydrogen induced cracking that extends radially along the seam, and which is different from classic step-wise cracking. Included in the method is evaluating the strength and ductility specimens taken from the tubular that have been hydrogen charged; and which provides an indication if the seam is susceptible to hydrogen embrittlement. The strength is evaluated by comparing tensile strength of the hydrogen charged specimen with that specified in an industry standard, such as API 5L. The ductility is evaluated based on comparing percent elongation of the hydrogen charged specimen with percent elongation of a specimen obtained from the tubular and not hydrogen charged. Tubulars with seams found susceptible to hydrogen embrittlement would not be put into sour service, whereas those found not susceptible to hydrogen embrittlement can be put in a sour service.

A method of managing a tubular having a seam that exhibits signs of hydrogen induced cracking that extends radially along the seam, and which is different from classic step-wise cracking. Included in the method is evaluating the strength and ductility specimens taken from the tubular that have been hydrogen charged; and which provides an indication if the seam is susceptible to hydrogen embrittlement. The strength is evaluated by comparing tensile strength of the hydrogen charged specimen with that specified in an industry standard, such as API 5L. The ductility is evaluated based on comparing percent elongation of the hydrogen charged specimen with percent elongation of a specimen obtained from the tubular and not hydrogen charged. Tubulars with seams found susceptible to hydrogen embrittlement would not be put into sour service, whereas those found not susceptible to hydrogen embrittlement can be put in a sour service.

The present invention relates to an absorption chiller which comprises an evaporator, an absorber, a regenerator and a condenser and has an absorbing solution and a refrigerant circulating. A heat transfer pipe, which is provided on one or more of the evaporator, absorber, regenerator and condenser, is comprised, and a ductile stainless steel pipe, which has 1% or less of delta ferrite matrix structure on the basis of the grain size area, is applied to the heat-transfer pipe. Therefore, copper-level flexibility can be obtained in comparison with an existing stainless steel pipe.

A method of controlling highly regulated power and frequency from a high frequency power supply system to provide a highly regulated power and frequency to a workpiece load where the highly regulated power and frequency can be independent of the workpiece load characteristics by inverter switching control and an inverter output impedance adjusting and frequency control network that can include precision variable reactor pairs with a geometrically-shaped moveable insert core section and a stationary split-bus section with a complementary geometrically-shaped split bus section and a split electric terminal bus section where the insert core section can be moved relative to the stationary split-bus section to vary the inductance of the variable reactors.

A method of preparing a pipe-section for welding to another pipe-section to form a pipeline comprising a plurality of said pipe-sections, the method comprising at least the steps of: (i) providing a pipe-section having first and second pipe-ends; (ii) defining a first portion L1 of the longitudinal length of the pipe-section from the first pipe-end being in the range 3% to 40% of the overall length of the pipe-section; (iii) defining a second portion L2 of the longitudinal length of the pipe-section from the end of the first portion L1 towards the second pipe-end; (iv) heating at least the first portion L1 to at least a first temperature T1 of at least 500 C. for at least 2 minutes; (v) maintaining a second temperature T2 of the second portion L2 during step (iv) below the first temperature T1. The invention is able to reduce the strain capacity during reel-laying of a pipeline formed from a plurality of pipe sections formed by the invention.

What is provided is an electric resistance welded steel pipe manufacturing device that is configured to perform welding while forming a strip-shaped steel sheet in a tubular shape and supplying a plasma flow to a pair of abutment end surfaces to perform shielding. The electric resistance welded steel pipe manufacturing device includes a mandrel; and a plasma flow feeder that is provided in the mandrel to supply the plasma flow.

A high frequency power supply system provides highly regulated power and frequency to a workpiece load where the highly regulated power and frequency can be independent of the workpiece load characteristics by inverter switching control and an inverter output impedance adjusting and frequency control network that can include precision variable reactors with a geometrically-shaped moveable insert core section and a stationary split-bus section with a complementary geometrically-shaped split bus section and split electric terminal bus section where the insert core section can be moved relative to the stationary split-bus section to vary the inductance of the variable reactors.

An electric-resistance-welded stainless clad steel pipe or tube that is excellent in both the fracture property of the weld and the corrosion resistance of the pipe or tube inner surface as electric resistance welded without additional welding treatment such as weld overlaying after electric resistance welding is provided. An electric-resistance-welded stainless clad steel pipe or tube comprises: an outer layer of carbon steel or low-alloy steel; and an inner layer of austenitic stainless steel having a predetermined chemical composition, wherein a flatness value h/D in a 90 flattening test in accordance with JIS G 3445 is less than 0.3, and a pipe or tube inner surface has no crack in a sulfuric acid-copper sulfate corrosion test in accordance with ASTM A262-10, Practice E, where h is a flattening crack height (mm), and D is a pipe or tube outer diameter (mm).