Complying with DM series installing dimensions, a typical seal designed for low and high temperature media, with connecting structure by flanges, flat seal gasket and screws, made all in materials resisting to low and high temperature and suitable for all trades, particularly for delivery of high temperature media in oil refinery and chemistry industry. Design characteristics: 1. Modular design; 2. Metal bellows; 3. Insertion of low expanding metal; 4. Connection by flanges and screws; 5. Forced internal cooling; 6. Flat seal gasket. Performance parameters: Temperature:>-75oC~400oC Pressure:0~2.5Mpa,make sure not to leave in operation at negative pressure or in vacuum state. Speed:30m/s(less than 6000rpm) Range of dimensions: 30~100mm.