The Ultra-low temperature top-mounted fixed ball valve is characterized by:

1. The body of the Ultra-low temperature top-mounted fixed ball valve is connected to the bonnet by studs, the ball is turned up and down by a support shaft, the lower support shaft is fixed on the valve body, the upper support shaft is fixed on the bonnet, and the ball passes through a rectangular The groove is connected with one end of the valve stem, and the other end of the valve stem is embedded in the keyway of the actuator, and the actuator is fixed with the bracket.

2. The bonnet of the Ultra-low temperature top-mounted fixed ball valve has a long neck structure. There are drip plates welded on both sides of the long section of the bonnet. The bonnet is equipped with a stuffing box. The low-leakage combined packing passes through the packing gland, packing The gland, the nut and the stud are pre-tightened, and a butterfly spring is arranged between the nut and the stud.

3. The flange on the Ultra-low temperature top-mounted fixed ball valve stem is provided with a wear-reducing pad and fixed by the valve cover.

4. There is a wound gasket at the connection between the Ultra-low temperature top-mounted fixed ball valve body and the bonnet, and there is a combined valve seat between the valve body and the ball. The combined valve seat includes a wave-shaped compound spring, a pressure ring, a pan Plug ring, seat ring, fireproof ring and seat sealing ring; the wave-shaped compound spring is installed between the valve body and the pressure ring, and the pressure ring is installed on the outer circle of the seat ring step, and the end face is in contact with the wave-shaped compound spring. The plug ring is installed on the outer circle of the valve body and the valve seat ring, the fireproof ring is installed in the annular groove of the valve seat ring, and the valve seat sealing ring is pressed into the annular sealing groove of the valve seat ring by external force.

5. The pan-seal ring of the top-mounted fixed ball valve is made of metal material and non-metallic material for external compression molding; the non-metallic material is polytetrafluoroethylene PTFE, polychlorotrifluoroethylene PCTFE or improved tetrafluoroethylene PTFE, and the metal material is El Kiloy Elgiloy or Inconel Inconel.

6. The Ultra-low temperature top-mounted fixed ball valve seat sealing ring is made of tetrafluoroethylene PTFE or polytrifluorochloroethylene PCTFE material with low temperature resistance.