Large flange

Large flange refers to the flange that exceeds the size specified by the relevant national departments. Generally refers to DN2000 above the size of the flange. Such products are all welded products, there is no wire buckle, and wire buckle products are often used to DN15-DN100 specifications. National flange standard GB/T9119-2010 in the 0.25MPa to 1.6Mpa pressure standard in the largest size is DN2000. To 2.5MPa pressure standard is the largest to DN800. The production of such flanges are to let the construction side to provide drawings to the production. The Production process has forging and rolled and spliced three kinds. The product size is too large can only be rolled and splicing process.

Product Information

Product Process

The center plate is first cut into suitable strips, the length of which is determined according to the specifications of large flanges. Then it is rolled into a circle by ring-rolling machine, and the interface is firmly welded by welding rods, and the welded joints should be inspected by X-spectrum. Then use the press to flatten it, and then use the lathe to process the waterline, chamfering and other processes, and finally use the indexing disk with the drilling machine for bolt hole punching processing. When playing bolt holes, it is not possible to play bolt holes in the place where there are large flange welds.

The cost of rolled flanges is lower than forged ones. But some oversized flanges cannot be forged. These products are mostly weighted by theoretical weight, and the weight of waterline, stop, bolt holes and chamfering is not subtracted in the calculation. The price of flat products is low, but if there is a dovetail groove process or the thickness of the large flange is particularly thin, the price will be higher. The reason is a complex processing and thin products and thick products spend the same process. Theoretical weight is calculated according to the following formula.

Material

Materials are stainless steel 304, 316, 316L, 2205, 2507, 201, 304L, 321 and other materials, carbon steel A3, Q235, A105, 10 #, 20 #, Q345, A182, 16MN and other materials, alloy steel 12cr1mov, 15crmov910, 15Mo3 15CrMoV, 12CrMoV, 45Cr, 50Cr and other materials.

Transportation Precautions

Products above 3 meters (including) should pay attention to the transportation matters when contracting. The limitation height of highway or general viaduct is 4.5 meters. The flange itself is 3 meters in diameter, then add the truck itself about 1.5 meters in height, will not be able to pass. If transported horizontally, 3M large flanges will also exceed the width of the carriageway, so that whether in vertical or horizontal transportation is a problem. Distribution of the problem is not solved, will cause some difficulties in transportation. Extra-large flanges should be completed by segmented production process. And then to the construction site for splicing.

Packing

After applying antirust oil, Large flange is packed in wooden case or wrapped with braided tape, depending on the situation.