Specializing in the production of serpentine pipe, boiler production process, almost all of the appliances by a tube, some are due to pipe is s, so named serpentuator. The serpentine tube is mainly composed of pipes, connecting accessories and hanging devices. The components of the serpentine tube in a boiler generally include superheater, reheater and economizer of the boiler.
I. Manufacturing process of serpentine tube
Raw material inspection-label displacement-(1)Pipe selection-(2)Cutting-(3)Chamfering-(4)Polishing-(5)Cleaning-(6)Mechanical welding-(7)RT inspection-(8)Lofting-(9)Bending-(10)Correction-(11)Extrusion(12)Manual Argon Arc Welding(13)X-ray inspection-(14)Solid solution treatment of stainless steel elbow-(15) Piping -- (16) Loading General Sample -- (17) Spectral Inspection -- (18) Welding -- (19) Row Correction -- (20) Grinding Detection Surface - MT or PT Inspection -- (21) Heat Treatment -- (22) Piping End Residual -- (23) Piping End Slope -- (24) Hydraulic Pressure Test -- (25) Through Ball -- (26) Cleaning Set Box and Pipe Screen (27) Container and Pipe Screen (28) Welded Together (29) X-ray Inspection (30) Weld Joint Heat Treatment (31) Cleaning (32) Oil Tank (33) Delivery
II. Main production equipment of serpentine tube
1. hot wire TIG welding: the outer diameter of the pipe is 31.8-76mm, and the thickness of the pipe is 3-12.7mm.
2. Continuous roller bottom heat treatment: It is a natural gas heat treatment furnace with continuous heat treatment tube panel. The tube panel enters from one end, and then slowly enters the heating zone, the heat preservation zone, and then passes through the slow cooling zone until the furnace is discharged. Furnace size 3712 * 13920 * 500 (width * length * height), maximum workpiece size 18000 * 3400 * 500 (length * width * height) can handle the maximum size of the tube panel is 3300 * 800, and the highest temperature of heating is 800%.
3. The third snake-shaped pipe production automation line: the main equipment includes two system pipe benders, one double-sided double R pipe bender, long pipe storage, pipe delivery trolley and raceway, upsetting device and auxiliary clamping. Induction heating device, turning device, circumferential pushing device, transverse feeding device, hydraulic system, electrical system and bending platform.
III. Requirements for serpentine welding
Generally speaking, for the welding of pressure components and accessories on pressure components, the welder must hold the "Boiler Pressure Vessel Welder Qualification Certificate" and carry out the welding work within the validity period and examination qualifications. Welders shall be welded in accordance with the Welding Procedures (WPS, WI) and shall mark the welder's steel mark in the vicinity of the weld as required. The welding materials used must be inspected and qualified in the factory, and their baking shall be carried out according to the instructions for the use of the welding materials or the corresponding process documents. The welding procedure must be guided by welding procedure (WPS, WI).
IV. Requirements for butt welding of serpentine pipes
1. the welding equipment is in good condition, the work is normal, and the instrument check is in the effective time.
2. oil and rust shall not be found on the surface of the welding wire.
3. welding groove meets the standard requirements (DG 2501). Grinding and cleaning the groove are metallic luster.
4. the welded pipe should be aligned, the inner edge is less than 0.5mm, and the outer side is less than 1mm.
5. welding according to welding parameters such as welding current and arc voltage of process document (WPS).
6. there should be no rough welding wave, groove, weld bead, blowhole, crack and so on. The undercut is less than 0.5mm.
7. The surface of butt weld should not be lower than base metal, and the butt weld should be smooth transition with base metal. The butt weld of water wall pipe should be ground flat to facilitate full contact between pipe and flat steel.
8. check 100% RT after welding.
V. Welding requirements for serpentine pipe accessories
1. clean up dirt and oil dirt in welding area.
2. assemble and weld according to drawing requirements.
3. the selection of welding materials shall be carried out according to WPS/WI, and the welding specifications shall be strictly carried out according to the welding procedure regulations. In particular, welding current is particularly important. For stainless steel welding materials and Ni327 welding materials, welding should be carried out according to the stipulated lower limit. When welding, the moving rod should go straight without swinging. The arc pit should be filled at the end of the arc to prevent hot cracking.
4. when attachments are welded, no arc should be placed on the pressure components. After welding, check according to process documents (MT/PT).