Half - ball valve in addition to normal as a full - open and closed use, can also be used for regulation and throttle.However, special attention should be paid to the flow direction of the medium to avoid erosion or wear of the sealing surface.(slurry valves and pulverized coal valves are strictly prohibited for regulation) in the petroleum, chemical, metallurgy, electric power, gas, ash, pulverized coal injection industry is the gate valve, globe valve, ball valve replacement products.
Structural characteristics of
Because of the eccentric structure, the valve in the process of closing, the ball gradually close to the seat, to close the position of full contact;When the ball leaves the sealing position when it is opened, it will be completely detached and the opening torque will be small.The second characteristic is that the sealing surface can realize self-cleaning, when the ball leaves the valve seat, the medium can be washed away the accumulation on the sealing surface, for easy crystallizing medium, the ball can be removed during the closing process to achieve the purpose of sealing, avoiding the disadvantages of other valves can not be opened;The third characteristic is tight seal, ball rest, valve seat is bimetal, adopt different technology, the sealing surface can be combined into various types such as anticorr-osion, wear resistance, to meet the needs of different working conditions, seal is spherical contact, by two-dimensi-onal eccentricity to achieve zero leakage;The fourth characteristic is that when the sealing pair is found to be worn for a long time after use, only when the pressing sleeve is closed and a little more pressing can still achieve reliable sealing and extend the service life.In addition, adjust or replace the seal pair, the valve can continue to use, to avoid the current many valve seal failure of the abuses of the whole scrapped.
The valve installation
Install directly on the line according to the direction of medium flow marked on the valve body.Generally, it can be installed in any position of the pipeline.If the valve is used for fluid containing particles and suspended solids, it can be installed either horizontally or vertically.When installed horizontally, the axis of the disc is parallel to the direction of flow from the seat end into the body and the disc opens when rotated.For vertical mounting, hold flap on upper half of body;Its seat end is positioned as shown.
If it is not strictly closed, loosen the nut on the limit screw on the hand wheel side of the gear reducer, turn the hand wheel, close the valve, tighten the limit screw, return to half circle and lock the nut.For wear and tear during long term use of packing, simply tighten the gland nut evenly to prevent leakage (do not tilt the gland).If replacement packing is required, close the valve.
Shape and connection dimensions
Eccentric half ball valve structure decomposition
Recommended installation locations for valves with particulate and suspended solids in working media
API ANSI B16.5-RF