What flow valve is appropriate to use in a circuit where only the extension speed of a cylinder is controlled?

• A. One-way flow control valve
• B. Two-way flow regulating valve
• C. Needle valve
• D. Proportional valve

Answer: (A)

When you want to adjust only the cylinder’s extension speed, you need a valve that throttles flow in just one direction. A one-way flow control valve does exactly that: it provides adjustable restriction for the extending direction while allowing free flow in the opposite direction (often via an integrated check valve). This means you can slow down the extension without slowing the retraction, which is the desired behavior in this setup.

The other options don’t fit as cleanly. A two-way flow regulating valve tends to affect both directions, making it harder to keep retraction fast while controlling extension. A needle valve can throttle flow, but without a built-in, reliable one-way function, it would typically slow both directions or require additional components to bypass retraction. A proportional valve offers precise, electrically controlled flow in both directions but is more complex and unnecessary when you only need directional speed control.

So, the one-way flow control valve is the best choice for controlling only the extension speed.