What Should be Noticed about Large Diameter Flange Sealing
Large diameter flange is a kind flange, it is generally used and popularized in the machinery industry, chemical industry, wind power industry, sewage treatment industry, getting the user's praise and favor.
The application of large diameter flange is extensive. The production process is divided into rolling and forging, and the especial large can only be rolled. Materials for large diameter flange are carbon steel, stainless steel and alloy steel, etc..
Large diameter flange has slip-on flange and welding neck flange. There is no large diameter threaded flange. In real production and sales, slip-on flange accounts for large. The structure and use range of slip-on large diameter flange and welding neck flange large diameter flange is not the same. So consumers should use different flange for different purpose to make sure the flange to make full play. Rigidity of large diameter flange is applicable in occasions of the pressure P is less than or equal to 4 MPa; neck welding flange also known as high neck flange, with large rigidity, it is suitable for the occasion of high pressure temperature. The types of flange sealing surface are following three: planar sealing surface for the pressure is not high, and medium is non-toxic occasions; uneven sealing surface for the pressure slightly higher; tongue and groove sealing surface for flammable, explosive, toxic, medium and high pressure situations. Different flange pipe fittings with different properties have good performance in different areas. They adapt to the different occasion and space, and the effect will be different.
The sealing of the large diameter flange is the two sealing faces of the bolt to squeeze each other and form a seal. But it also leads to seal damage. In order to keep the seal, you have to maintain a huge bolt force. Therefore, the bolt needs to be even greater.
And the greater bolt must match the larger nut. This means that larger diameter bolts need to create conditions for tightening nut. The greater of the diameter of the bolt, the more curved of the applicable flange; the only way is to increase the thickness of the wall of the flange parts. The whole device will require a great deal of size and weight, which is a special issue in the offshore environment, because in this case the weight is always the main problem that people have to pay attention to. Flange is an invalid seal; it needs to put 50% of the bolt load for the compression gasket, and the load used to maintain the pressure only left 50%.