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Product Name: |
Flat-plate Gate Valve
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Supply Ability: |
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Related proudcts |
valve, gate valve, |
Specifications |
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Price Term: |
FOB,CFR,CIF |
Port of loading: |
TIanjin,China |
Minimum Order |
1 |
Unit Price: |
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Working principle 1、With equal pressure throughout the valve(and the gate in closed position), and initial seal (1) is formed with the raised PTFE ring on the faces of the seats. (The seat-inserts clean both sides of the gate each time the valve is opened or closed). (Fig 1) 2、As line pressure (2) is applied to the valve. it acts on the gate, forcing it against the PTFE ring on the downstream seat, compressing it until the seat against the steel seat. Thus, a double seal is formed...first, a PTFE-to-metal seal; then, metal-to-metal. The seat is also forced firmly into its recess. The O-ring (3) prevents any downstream flow at this point. (Fig 2) 3、Upstream seal is provided when valve cavity pressure is bled off. This is caused by the force of line pressure acting against the upstream seat (4) moving the seat against the gate and providing a tight PTFE-to metal seal at this point. At the same time. the O-ring (5) forms a tight sea with the seat recess. (Fig 3) 4、Valve automatically relieves itself of excessive valve cavity pressure. When valve cavity pressure exceeds line pressure...from such causes as thermal expansion...the upstream seat is forced back into its recess and the excess pressure in the valve cavity is bled between the seat and the gate into the line. (Fig 4)
Flow characteristic The flow characteristic of flat gate valves with a diversion hole is equal to that of pipelines of the same specification. The characteristic is shown in per centum form. As for valves without a diversion hole its cavity fly ***n is smaller than that of wedge gate vales and it is a regular cylindrical object, therefore, characteristics of the valves are similar except that they have a larger pressure loss. Besides, their flux adjustment behavior is better than that of the ones with a diversion hole. Outside |
Company: |
Beijing St.Ocean Engineering Technology Co.,Ltd.
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Contact: |
Ms. Britney Lee |
Address: |
Room 338,Building No.10,En Ji Xi Yuan,No.1Liang Jia Dian,Fuwai Avenue, |
Postcode: |
100142 |
Tel: |
86-10-51660591 |
Fax: |
86-10-51660593 |
E-mail: |
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