I'm trying to design a somewhat complex small system, in which based on the configuration of certain other valves, water could be flowing along a pipe in either direction.

To be clear, given any particular configuration of the other valves the flow direction should be entirely fixed. But different configurations could lead to that fixed flow being one way, or the other.

Given the complexity of this design, it would be nice to be able to put in something that ensured that the water was flowing in the expected direction. So ...

Do there exist valves which are mono-directional, but where I can (by e.g. turning a handle) change the direction of allowed travel?

  • Maybe this is clear to somebody else, but I'm not envisioning what you want. Can you provide a diagram or two to show what you want?
    – tnknepp
    Dec 23, 2020 at 10:50
  • it sounds like you want a reversible check valve.
    – Jasen
    Dec 23, 2020 at 10:58
  • @kris Your link isn't working. (It looks like the URL and the display-text are swapped.)
    – Doug Deden
    Dec 23, 2020 at 16:48
  • Is this a system that relies on gravity for flow?
    – Kris
    Dec 24, 2020 at 3:33
  • No. Flow is determined/created by mains pressure. Direction of flow is determined by valves.
    – Brondahl
    Dec 24, 2020 at 9:01

2 Answers 2


Evidently. One of several rsults of searching for reversible check valve. Image from flow-rite.com, no affiliation, never heard of them

enter image description here

However, I'd suggest re-examining the entire design. When complexity leads to wanting more complexity, it's more often an overly complex design ethos than a need for complex parts.

  • Perfect, thanks for the keywords to search for! Agree that the design is complex, but I think that's all derived from inherent complexity in the goal :D Once I've finished thinking about all the details, I may put the whole plan up here, to ask if there are any high-level flaws or improvements available. But at the moment I want to check my low-level details first :)
    – Brondahl
    Dec 23, 2020 at 14:02
  • 1
    A valve may have a way to check water from traveling in either direction but it does not change the direction of the flow of the water. A valve is not what moves the water in the pipe. That is accomplished with gravity or by mechanical means. The valve is open or closed, it does not pump. What is the reason for wanting water to travel in either direction (or blocking it from traveling in either direction) in a pipe? Perhaps there is a simpler way to accomplish your goal.
    – Alaska Man
    Dec 23, 2020 at 18:12

You might try looking up directional valve, T-port valve, and three-way valve. These are specialty valves that would likely be for industrial use; not commonly found in domestic water-supply scenarios so not available at a local plumbing or home improvement shop.

enter image description here

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