API 6D Non-Slam Axial Check Valve

API 6D Non-Slam Axial Check Valve

Contact: Email: zipopvf@163.com Wechat: zipo2019; QQ: 2191417589; Mobile: 18081659672 

Please inform us of the accurate nominal size, pressure class, medium, temperature, material, actuator and other parameters, before consulting or purchasing the product. Thanks!

The working principle of axial flow check valve: the opening and closing of the valve disc is determined by the pressure difference between the inlet end and the outlet end of the valve. When the pressure at the inlet end is large and the pressure at the outlet end expands the sum of spring force, the valve disc opens. As long as there is a pressure difference, the disc is always open, but the opening degree is determined by the pressure difference. When the sum of the pressure at the outlet and the spring force is greater than the pressure difference at the inlet, the valve disc is closed and always closed. Since the opening and closing of the valve disc is in a dynamic force balance system, the valve is in a balanced operation, no noise and water hammer phenomenon is greatly reduced.

If the fluid velocity and pressure cannot support the valve at a large open position and maintain it in a stable open position, the disc and related moving parts may be in a state of continuous vibration. In order to avoid premature wear of moving parts, noise or vibration or vibration operation, it is necessary to select the size of the check valve according to the fluid state. 

Characteristics of axial flow check valve

1. Single structure, light weight, good rigidity and easy maintenance;

2. The thrust of the spring enables the disc to handle the closed position even under the action of no medium pressure;

3. The good support mode enables the valve disc and seat to be in good alignment no matter what installation position the valve is, so the valve can be installed at any angle.

4. The combination of streamline design of valve sleeve shape and body cavity streamline design constitutes the streamline flow channel of axial-flow check valve. Accurate calculation and design make the flow area of flow passage sufficient and consistent, small pressure loss, stable flow state and no cavitations. When the medium flows, the disc will return under negative pressure and spring thrust, and there will be no direct impact of medium on the back of the disc; therefore, the axial-flow check valve is a low-noise valve.

5. The special surface treatment and structural design of the supports at both ends of the valve disc and the valve disc shaft overcome the blocking phenomenon often occurred in the use of similar valves, and the opening and closing are stable; at the same time, the defects such as the valve disc's neutral difference, uneven stress on the sealing pair and the inconsistent position of the sealing pair between the two actions which affect the sealing performance are avoided, so that the sealing pair is always in good condition.

6. Precise design uses spring thrust. When the valve disc is in the closed position, the spring thrust is slightly greater than the sum of the valve disc gravity and the friction force between the valve disc and the front and rear supports. The valve disc can not only reseat and seal under low pressure and arbitrary installation, but also realize low-pressure opening, reduce the starting load of the pump and protect the operation safety of the pump.

Application of axial flow check valve: in the fields of petroleum, chemical industry, metallurgy, power station, etc., corrosive media such as water, oil, gas and various chemicals. Suitable temperature: 250 ~ + 590 ℃; gasoline, kerosene and other media, low temperature and cryogenic devices, vacuum system, such as kerosene storage tank liquid jet fire fighting system, LNG; applicable temperature: - 196 ~ + 280 ℃

Specification for axial flow check valve: 

The design, manufacture and inspection of the valve comply with the provisions of ANSI and API. 

The structure length conforms to the provisions of ANSI B16.10 and GB/T12221; the connection end can be provided with flange, butt welding, socket welding, threaded end and other connections according to the user's standard.

Manufacturer: ZIPO VALVE & PUMP CO., LTD