Industry News

The production and processing methods about beveling machine for pressure pipe making(1)

1 Project Overview             

Second seat Jinping Hydropower Station in Sichuan Liangshan Yi Autonomous Prefecture Muli, Yanyuan on the Yalong River, at the junction of three counties mianning Jinping Great Bend, karaoke system to the Yalong River estuary five development Step Power station. Jinping hydropower utilization Yalong Bay 150km Jinping large natural gap, straighter tunnel excavation of diversion and power generation. Jinping dam located downstream of 7.5km at a plant located in the eastern end of a large bay big ditch. Normally, the reservoir 1646m, backwater length of 7.5km, corresponding storage capacity is 14.01 million m3, reservoirs dead water level 1640m, fixed capacity of 9.05 million m3, regulating capacity of only 4.96 million m3. Wan power plant total installed capacity of 8x60 kW, for many years the average annual generating capacity of 24.23 billion kW · h. Header set low gate, gate access to the basin area of 103 000 km2, gate site at annual average flow 1220m3 / s. Reservoir has daily regulation function, and JinpingI synchronous operation with annual regulation characteristics.

Jinping Hydropower Station were arranged eight penstocks, penstock pipe sections each average about 175. Pipe maximum diameter 6.5m, the minimum diameter of 6.05m, the maximum length of a single axis of 3m, a single minimum axial length of 1.296m. 8 penstock in the direction toward the upstream segment 28.8m from the plant upstream side wall at 2.38m (penstock end), the use of 600MPa high-strength steel. The inner diameter of the pipe section is 6.05m, 6.5m and 6.05m ~ 6.5m gradient of the cone, its thickness, respectively 56ram, 52mm, 48mm, 44mm, 40mm. The remaining segments are used 16MnR 500MPa grade pressure vessel steel, the main part of the high-pressure pipeline including flat section, the curved section, the shaft section, recurved segment and a lower flat section, the inner diameter of the steel pipe are 6.5m, steel plate thickness of 20mm, respectively, 22ram, 24mm, 28ram, 36ram, 38mm, single pipe length of 447m ~ 490m. 8 are set to the full length of penstock stiffener ring materials are 16MnR of 500MPa grade pressure vessel steel.

My unit construction of most of the pressure pipe manufacture, wherein the sheet 38ram below, all using the slope machining automatic beveling machine performed. In penstock peak production, groove preparation step is very compact, and met head off sheet in the sheet metal processing, beveling machine does not walk on the sheet, the sheet processing blunt edge sample sizes and other issues affecting the penstock production efficiency, delay the construction period. How safe, efficient, and shelf life of the penstock plate processing, it is particularly important.


2. Preparation prior to processing           

Manshuiwan steel from the transfer station to the factory ship, there should be full-time personnel hoisting steel, industrial pipe portion, Ann prime rings, maintenance personnel should be the Ministry of plate thickness, type, size, weight, arrival time, make a record and acceptance. Lifting operations should pay attention to the signal, commanding officers and the driver to concentrate on operating, accurate, 10cm ~ 30cm, smooth and rope force to check whether an object even after lifting the load off the ground, the brake mechanism is safe and reliable; lifting member when the angle between the wire rope should be less than 60. And to ensure that the choice of wire rope safety factor of more than 8 times; according to the type of material, the thickness of the stacked classification and woods support pad, the pad off the ground, the upper awning material should be added to prevent corrosion, contamination and deformation. Press the assembly sequence, the sheet transport by truck to the CNC cutting machine platform, records indicate good plate number NC increases the drawing sheet model corresponding (Technical Department prepared after the copy to the CNC cutting machine), according to the drawing on the plate rehearse, cutting. Groove preparation is an important step and it requires penstock longitudinal seam, girth were "X" slope processing, in order to step slope butt welding, the joint can occur without penetration process defects.