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Goodfriends Import & Export CO.,LTD
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 Model Number |
GF-31101 |
Wedge gate valve
Advantages and purpose
The opening ＆ closing part of gate valve is gate disc, its movement direction is vertical to that of liquid, and the gate valve is only used to open and close fully, but not to adjust the flux. The disc has two seal surfaces, for the most general wedge pate valve, its two seal surfaces form the wedge each other, and the wedge angle is different for different valve parameters, it is 5°generally, and 2°52′when the medium temperature is not high. The disc of wedge gate valve may be made into a whole, i.e. the rigid gate disc, or may be made into a kind of little distortion disc, which is available to improve its craftwork and makes up the deviation of seal surface angle caused in the processing course, i.e. the flexible gate disc.
When the gate valve is closed, the seal surface is available to seal by the pressure of medium, i.e. relies on the medium pressure to push the seal surface of gate disc down to the seat on the other side, which is just called self-sealing. Most of gate valve adopt the compulsive seal, i.e. when the valve is closed, it relies on external force to compulsively push gate disc down to valve seat to ensure the seal of seal surface.
Which its gate plate moves in straight line together with valve stem, is called rising stem type gate valve (also outside screw rising stem gate valve)
Generally, the ladder-shape screw on rising stem changes the rotary movement into a straight-line movement through the nut on top of valve and the guidance on valve body, i.e. changes the operation torsion into operation thrust.
When open the valve, and the gate disc rises to the height as much as the valve diameter, the liquid passage is through fully, but it can′t be monitored on this position. In the practical operation, it uses the peak of valve stem as the mark, i.e. the non-lifted position as its full-open position. Considering that the change of temperature probably results in locked status, the stem is usually returned 1∕2～1 round when the gate disc rises to the top position, i.e. as the full-open position. Therefore, the full-open position is decided by the position of gate disc (i.e. the stroke of gate disc).
1. Small resistance to liquid, and small erosion to seal surface
2. Force saved to open and close
3. No limitation for the flow direction of medium, no blocking, no pressure reduction.
4. Simple figure, short body, good craftwork, and extensive application range
The below-noted items for installation and maintenance of gate valve
1. The handwheel, handle and driving device are not allowed to lift things, and the collision is forbidden.
2. The double-disc gate valve should be installed vertically (i.e. the valve stem is vertical, and the handwheel is on the top).
3. For the gate valve with by-pass valve, should first open the by-pass valve before open the valve (to balance the pressure difference between exit and entry, and to reduce the opening force).
4. For the gate valve with driving device, install it as per the use instruction.
5. lf often use the valve, lubricate me at least every month.
Standard and regulation
Design and Manufacture：GB/T12234
Face-to-face-dimension：GB/T12221; GB/T151881.1
Pressure Temperature rating：GB/T12224
Flange connection dimension：JB/T79; GB/T9113
Butt-welding ends: GB/T12224
Inspection and test：JB/T9092; GB/T13927
Driving manner: Manual operated, Worm gear operated, Pneumatic operated,
Electric operated
Model: Z40H（Y） Z41H（Y） ?Z940H（Y）? Z941H（Y）
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