中文字幕一二区二区三区,国产成人午夜欧美日韩精品乱码,伊人久久大香色综合,亚洲精品国产丝袜久久下载,亚洲色图在线精品视频,亚洲国产精品久久九色,永久在线免费观看视频地址,成人av一区二区三区久久,少妇人妻偷人中文字幕

　　Main purpose：Magnesium alloy sacrificial anode used in underground and fresh water in the oil, gas, water supply and drainage pipeline, underground cable, chemical industry, communications, harbor, shipping, reservoir gate and other projects of corrosion protection.

　　Execution standard：GB/T 17731-2009

　　Chemical composition

　　Buried pipeline\The outer wall and underground storage tank the sacrificial anode metal structure commonly used specifications

　　The electrochemical properties

　　Anodic installation method

　　(Soil environment)

　　⑴ anodic bed structure

　　In order to ensure that the sacrificial anode is stable in the soil, the anode is filled with the appropriate chemical packing material, the anode and the soil are adjacent to the anode and the filler adjacent to improve the working environment of the anode; reduce the anode grounding resistance and increase the anode output current; The chemical composition of the filler favors the dissolution of the anodic product, does not scab, reduces the unnecessary anodic polarization; maintains the anode to long-term wetting. The basic requirements for chemical fillers are:

　　Low resistivity, good permeability, easy to drain; good moisture retention. Sacrifice anode packing material useful bags and field drilling in two ways, pay attention to bags of bags must be natural fiber fabric, is strictly prohibited the use of chemical fiber fabrics. Field filling effect is good, but the filler to be large, do not pay attention to easy to soil into the filler, affecting the quality of the package, the thickness of the filler should be in all directions to maintain 5 ~ 10cm. Common packing material formula see table:

　　⑵ layout of the anode bed

　　Sacrificial anode distribution can be used in a single or concentrated group of two ways, the anode buried into vertical, horizontal two, buried in the direction of axial and radial. Anode buried position generally from the outer wall of the pipe 3 ~ 5m, the minimum should not be less than 0.3m, buried depth to the top of the anode from the ground should not be less than 1m is appropriate for the northern region, must be below the permafrost. Group laying, the anode spacing of 2 ~ 3m is appropriate. In the dry ground below the ground level of 3m, the sacrificial anode should be deepened. For rivers and lakes, the sacrificial anode should be buried in the safe part of the riverbed (lake bottom) as possible to prevent flooding and dredging. When using sacrificial anodes in urban and pipe network areas, it should be noted that there should be no other structures, such as cables, water, steam, pipes, etc. between the anode and the protected structure.

　　Sacrifice the anode group on the pipeline spacing, for the long-distance pipeline for 1 to 2 groups / km, for the city pipeline and station pipe network to 200 ~ 300 group is appropriate.

　　Schedule: