Has anyone used a two-stage switch ball valve?
Thread Content
Could someone briefly explain its operating principle? Does anyone know what the difference is between its cylinder structure and that of a regular cut-off ball valve?
A two-section switch ball valve is actually divided into three sections: a middle section and two sections on each side. The middle section is controlled by a solenoid valve to switch between fully closed and fully open positions. When it is in the fully open position, the two sections on either side are adjusted using another solenoid valve (which causes the two auxiliary pistons to push the main piston inward)
Where does the air outlet of the solenoid valve on the left go?
The solenoid valve on the right side has two air outlets, one on the left and one on the right. Wealthy people can also install solenoid valves on both sides; as long as power is supplied to them, it will work
This post was last edited by lng Elegance on 2015-10-12 at 12:18. Well, I won’t say much more; it’s almost done
A single-acting cylinder requires only one air source; it relies on a spring for repositioning. The interlocking of the two solenoid valves is intended for safety reasons. In fact, in many cases on site, it’s sufficient to simply install a positioner
So how does he achieve a two-stage switch? If the valve is stuck, how can one tell if it is open halfway?
Your diagram isn’t a three-position one; it shows the full open position on the cylinder, as well as the off and half-open positions. There’s a shaft on the cylinder equipped with a limit switch, and it’s at that location that the angle can be seen
The two-stage pneumatic ball valve converts the opening and closing action of the ball valve into operation at certain angles (offering positions of 0°, 45°, 90° or 0°, 90°, 180°). This slows down the speed at which the valve opens and closes, resulting in a smoother flow of fluid in the pipeline. It prevents water hammer effects caused by shocks, which could lead to explosions of flammable fluids, and it also avoids damage to flow meters and other instruments in the system. We used this type of valve in a project for foreign clients; they were the ones who requested its use.
What I mean is that when this valve is open to half, the pneumatic positioner outputs a certain pressure. In the event that the valve gets stuck and cannot be opened to half, how does the pneumatic positioner know that it hasn’t reached half openness? How can it ensure that the valve is indeed open to half? ? ? Thank you for asking so many questions. . .
I can’t answer that one; is it stuck? Then it’s necessary to check whether the signal sent by the locator is correct, and to verify whether the valve is indeed stuck and unable to move