Five basic types: flat welding flange, butt welding flange, threaded flange, socket welding flange, loose flange. (RF), concave (FM), concavo-convex (MFM), tongue and groove (TG), full plane (FF), and ring connection (RJ) are commonly used.
Flat welding steel flange: for the nominal pressure of not more than 2.5MPa of carbon steel pipe connection. Flat welding flange sealing surface can be made of smooth, concave and convex and tongue and groove three. Smooth-type flat welding flange of the largest application, more for the medium conditions are more moderate conditions, such as low-pressure non-purified compressed air, low pressure circulating water, it has the advantage of cheaper prices.
Butt welded steel flange: for the flange and pipe counterpart welding, its reasonable structure, strength and stiffness, can withstand high temperature and pressure and repeated bending and temperature fluctuations, reliable sealing, nominal pressure of 0.25 ~ 2.5MPa The butt is made of bump.
Socket welding flange: commonly used in PN ≤ 10.0MPa, DN ≤ 40 in the pipeline.
Loose flange: loose flange commonly known as live sets of flanges, split ring live sets of flanges, flanging sets of flanges and butt welding flanges. Commonly used in medium temperature and pressure are not high and corrosive Strong situation.
The whole flange: often with the flange and equipment, pipes, fittings, valves, etc. made of this type of equipment and valves commonly used.