Large diameter flange as a common flange, because it can be applied to a variety of different occasions and the advantages of good effect by the industry loved, the product is widely used in machinery and chemical industry and other industries, let DHDZ flange manufacturers to introduce the assembly principle requirements and anti-corrosion construction.
I. Assembly principle and requirements of large diameter flanges
1. When assembling a pair of flanges, the bolt holes of the mounting flanges should be aligned with the bolt holes corresponding to the fixed flanges and parallel to the fixed flanges. The deviation should not be greater than 1.5 and 2mm of the outer diameter of the flanges.
2. Check and correct the flange position from the left and right direction with 90 square feet, and finish spot welding and fixing the large diameter flange through the third and fourth point after spot welding.
3. When selecting the matching flanges of equipment or valve assembly, care should be taken to see if the flanges of the original equipment or valve assembly are the same as those used in the pipeline.
4. When assembling flat-welded flanges, the pipe end should be inserted 2/3 of the thickness of the inner diameter of the flange, and then spot weld the flange to the pipe. For horizontal pipe, spot weld from above, then check calibration flange position from different directions with 90 square feet so that sealing surface is perpendicular to center line of pipe, then spot weld below spot spot.
5. Before assembling the flange, clean the flange surface, especially the sealing surface.
Two, the operation process and characteristics of large diameter flange anti-corrosion construction
Sealing corrosion inhibitor for flange clearance filling of large diameter. Paste paper (transparent) tape on the flange edge to prevent the flange from being dirty when injecting corrosion inhibitor; Seal and fill flange clearance with corrosion inhibitor to ensure flange clearance is filled with sealing corrosion inhibitor.
After filling the flange gap with corrosion inhibitor, use the putty scraper to polish the surface smooth along the circumferential direction, so that the gap and the flange edge in the same plane. Tear off both sides of the tape.
If you use flange anticorrosion cream, you need to use a knife to cut the flange anticorrosion cream into narrow strips, and then according to the width of the flange gap, directly fill the flange gap by hand. Press down when filling.
Clearance and surface treatment of large diameter flange. Remove the rust on the flange clearance and screws with a brush; Clean flange clearance with compressed air; If chemical remover is used, evaluate whether chemical remover will affect flange seal.
If in doubt, it is recommended not to use chemical methods; Wipe flange surface with sandpaper or cotton yarn to meet ST2 standard.