Pneumatic Double Eccentric Butterfly Valve

Technical Parameters

Unique seat sealing structure

The butterfly valve according to independent form of overseas related products developed to improve the integration of the s-type elastic sealing seat structure, USES imported RPTFE material, good elasticity and long service life, can automatically compensate the change of temperature and pressure, and wear long switch used in sealing compensation; Can achieve two-way sealing leak; Using activity insert structure, maintenance convenient, don't need to remove the disc and stem, as long as the single side press plate, can replace the sealing seat and maintenance sealing surface.

Seat sealing

ANSI/FCI 70-2 provides control valve leakage levels and test procedures. Where the VI level is the lowest level of leakage. High performance of the clamp type butterfly valve can reach MSS-SP61 provisions of the bubble free seal, to be higher than the VI level.

Design of offset shaft and eccentric butterfly plate

• In open and in the middle position - seat and disc not contact;
• The seat part no wear points up and down;
• Low torque, small operator requirements.

When the valve is closed, the butterfly valve seat is slightly deformed, the deformation of the "incentive" of the valve seat, the valve seat sealing surface to keep it with the edge of the disc to maintain a permanent seal.

When insert the lateral compression, pressure is applied to further intensify the lip edge below the sealing force between valve disc and valve seat.

When the pressure is applied to the side of the non insert piece, the butterfly plate is pushed to the valve seat. Because the outline of the butterfly plate is spherical, the butterfly plate to the seat forward, the closer the close. The lip edge is in contact with the groove at the bottom of the insert, limiting the excessive movement of the valve seat.

Seat rated valueValve

curve on the seat rating for the seat, only is based on the full valve is closed Butterfly valves at the ends of the pressure difference. These ratings can be used as a general condition guidelines. In accordance with the According to past experience, the improved and other seat materials transformation, rating can be used Higher. For special conditions, please contact the company engineers.

Flow parameters

The following table provides a class 150 butterfly valve flow coefficient.Cv value indicates that pressure difference is 1 pounds per inch For 60 ° F (0.07 bar), temperature (15.6 ℃) per minute through the full open valve Of water flow, the unit for the number of gallons per minute.

Flow coefficient (Cv)

Body rated value

Maximum working pressure of the body and the body of various materials testing pressure valve is shown in the following Body pressure rating table. The actual working condition of using pressure rating to definitely according to the seat.

To confirm cv value of the valve at the middle position:

1.Confirm the per centage of the maximum Cv value from the curve

2.Multiply the percentage of the maximum Cv value from the curve by theCV value from the flow datasheet