The invention provides a pneumatic conveying system having a series of supply lines with at least portions of the lines being wear resistant to extend the useful lifespan of an agricultural product delivery applicator. The wear resistant supply line(s) may be made from a hard material and have a curve(s) defined by angled or mitered segments that are welded or otherwise joined to collectively provide the curve(s) The wear resistant supply lines may be at least partially reinforced by way of, for example, welded or other build up wear resistant material(s) at high wear zones of the supply lines.

A gas shield arc welding method that reduces the number of joints, which are the sites where defects occur more readily, and that enables automatic welding with a welding robot. A gas shield arc welding method in which a steel pipe Wo is welded by multi-pass welding with a steel frame erection adjusting tool attached to an erection piece on the steel pipe Wo to immobilize an open end section of the steel pipe. An initial single or several layers are welded to the open end section, after welding, the steel frame erection adjusting tool is removed; and remaining layers are welded with a welding robot such that two bead joints are formed at no more than two sites.

The present invention relates to a preheating device for welding oil, gas, and geothermal wellheads of varying diameters and thicknesses which is applicable to the oil, gas, and geothermal industry. The preheating of head and coating pipes to be welded do not cool down quickly. The cooling speed reduction prevents structures or joints from being less susceptible to cracking by maintaining the necessary heat thus preventing the integrity of the joints from being exposed. The preheating of head and coating to be welded maintains a uniform and constant temperature avoiding temperature changes, thus making the structures or joints less susceptible to cracking by maintaining the necessary heat and preventing the integrity of the joints from being exposed.

A process of welding fittings to ends of a double wall pipe comprising forming a first welded joint between an inner pipe and an inner receiver of a first fitting; forming a second welded joint between an outer pipe and an outer receiver of the first fitting; forming a third welded joint between the outer pipe and an outer receiver of a second fitting; and forming a fourth welded joint between the inner pipe and an inner receiver of the second fitting.

A device internally insulating a welded pipeline joint between pipes having an internal protective coating, in a first variant, includes a power actuator having a cylindrical elastic working member for radial expansion when excess pressure occurs inside its cavity. A cylindrical casing of elastic anti-adhesive material arranged coaxially on the member exterior can have channels for exhausting air and supplying a compound. In a second variant, the device sleevelessly insulates an annular space. A casing made of an anti-adhesive material is centrally reinforced by an elastic cord. Using a cylindrical elastic anti-adhesive casing coaxially arranged on the exterior of a power actuator elastic working member forms an annular space in the weld zone either using a protective sleeve, or by a reinforced casing portion. A vacuum in the space is filled by a compound. The elastic anti-adhesive material allows easy removal of the casing from the hardened compound surface.

A method for purging air from a structure to be joined by welding by feeding a liquid cryogen to the structure. The liquid cryogen will enter the structure, warm up and enter the gaseous phase very rapidly. The gaseous cryogen will displace the air that is present in the structure out of the structure and reduce the content of oxygen in the structure to about 10 parts per million when welding can begin.

Provided is a method for producing a circumferential weld joint. With this method, when low-carbon martensitic stainless steel pipes used for pipelines for transportation of petroleum and natural gas are subjected to circumferential welding, the circumferential welding can be performed efficiently using a low-cost welding material having a composition similar to the composition of the low-carbon martensitic stainless steel pipes. Pipe ends of low-carbon martensitic stainless steel pipes containing prescribed components are butted against each other and subjected to multi-pass arc welding using a welding material containing prescribed components. In the first pass in the multi-pass arc welding, CMT welding is performed in which the welding material is moved back and forth against a molten pool to generate an arc intermittently. In the second and subsequent passes, one selected from GMA welding, GTA welding, and the CMT welding is performed.

A process for preparing a multi-thickness welded steel vehicle rail, the process comprises the steps of: (a) forming a first tube having a first outer diameter, an inner diameter and a first wall thickness; (b) forming a second tube having the first outer diameter, a second inner diameter and a second wall thickness different than the first wall thickness; (c) swaging a first end of the first tube to a second outer diameter less than the second inner diameter of the second tube; (d) inserting the swaged first end of the first tube into an end of the second tube to form a joint; (e) welding the first tube and the second tube together to form a weld at the joint to form a tube blank with a heat affected zone of lower metal strength in the area of the weld; (f) preheating the tube blank to create a common crystalline microstructure along a length of the tube blank; (g) introducing the tube blank into a blow molding tool having inner molding walls; (h) molding the tube blank at an elevated temperature by expanding the tube blank against the inner molding walls of the molding tool by injecting a pressurized medium into an interior cavity of the tube blank; and (i) quenching the tube blank by replacing the pressurized medium with a cooling medium through the molding tool and the tube blank to achieve a rapid cooling effect on the tube blank and to create a completed vehicle rail with essentially uniform material strength across the weld. A completed vehicle rail has an overlapped welded structure and uniform microcrystalline structure along the length of the rail.

A circumferential welded joint of a line pipe is formed by butting against each other end portions of steel pipes having a yield strength according to 5L Specification of API Standards not smaller than 555 N/mm.sup.2 and welding the butted portions in a circumferential direction. A joint strength ratio σ.sub.match=(TS-w/TS-b).Math.(YS-w/YS-b) represented by a product of a ratio between a tensile strength TS-w of a weld metal and a tensile strength TS-b of a base material and a ratio between a yield strength YS-w of the weld metal and a yield strength YS-b of the base material, and a critical equivalent plastic strain ε.sub.p-cri [%] for ductile crack generation in a base material heat affected zone satisfy Equation (1), and the yield strengths YS-w, YS-b of the weld metal and base material satisfy Equation (2).
σ.sub.match>4.85ε.sub.p-cri.sup.−0.31  (1)
YS-w/YS-b≧1.0  (2)

A tube assembly includes at least first and second tubes configured for coupling at respective ends. The first and second tubes each include a base material, and a weld interface at the respective end. The weld interface is proximate to an inner diameter and an outer diameter of the first and second tubes, and includes a weld interface segment extending therebetween. A work hardened weld assembly couples the base material of each of the first and second tubes. The work hardened weld assembly includes a weld fusion zone between the weld interfaces of the first and second tubes and the weld interface segments of the first and second tubes. The weld fusion zone is work hardened and at least the weld interface segments of the first and second tubes are work hardened between the work hardened weld fusion zone and the base material of the first and second tubes.