Thread gate valve
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Product Description
Threaded gate valve, internal thread gate valve, high pressure gate valve, pipe cut-off valve is a forced seal valve, so when the valve is closed, must be applied to the valve pressure, in order to force the sealing surface does not leak. When the medium enters the valve body from below the disc, the resistance that the operating force needs to overcome is the friction force of the valve stem and the packing and the thrust generated by the pressure of the medium. The force of closing the valve is greater than that of opening the valve, so the valve stem The diameter should be large, otherwise the failure of the stem top bending will occur. In recent years, after the emergence of self-sealing valves, the flow direction of the cut-off valve is changed to enter the valve cavity from the top of the valve clack. At this time, under the action of medium pressure, the force of closing the valve is small, while the force of opening the valve is large, and the diameter of the valve stem can be reduced accordingly. At the same time, under the action of the medium, this form of valve is also more tight. China's valve "three to" has stipulated that the flow of the valve, all use top-down.
When the internal thread gate valve is opened, the opening height of the valve flap is 25% ~ 30% of the nominal diameter, and the flow has reached the maximum, indicating that the valve has reached the fully open position. Therefore, the fully open position of the stop valve should be determined by the stroke of the valve flap.
Features
1. Simple structure, manufacturing and maintenance is more convenient.
2. The working stroke is small and the opening and closing time is short.
3. Good sealing performance, small friction force between sealing surfaces and long service life.
4. The shortcomings of the threaded gate valve are as follows:
5. The fluid resistance is large, and the force required for opening and closing is large.
6. Not suitable for medium with particles, large viscosity and easy coking.
7. poor regulation performance.
8. The type of threaded gate valve is divided into external thread type and internal thread type according to the position of the stem thread. According to the flow direction of the medium, there are straight-through, DC and angular. Cut-off valve according to the sealing form, there are packing bellows gate valve and bellows seal globe valve.
Executive standards | Name | Design and manufacture | pressure test standard | |||
Reference standard | GB/T 12235 | GB/T 13927 | ||||
Main Parts Information | Name | 1-Body | 2-Valve plate | 3-Stem | 4-Mouth pad | 5-Bonnet |
Material and description | CF8 | CF8 | 304 | PTFE | CF8 | |
Dimensional information | DN | G | L | |||
15 | 1/2" | 52 | ||||
20 | 3/4 | 57 | ||||
25 | 1" | 61 | ||||
32 | 11/4 | 70 | ||||
40 | 11/2” | 74 | ||||
50 | 2” | 83 | ||||
65 | 21/2" | 106 | ||||
80 | 3” | 118 | ||||
100 | 4 | 126 | ||||
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Tianjin Hualida Valve Co., Ltd.
Address: Tianjin Jinan Industrial Development Zone
Mobile Phone: +86 15022758886
Website: www.hualidavalve.com
Mailbox: hualidavalve@163.com
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