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ScottG's avatar
ScottG
Nomad
Apr 19, 2021

Water valve directional?

I know valves similar to this one in the plumbing world are sometimes directional, and have an arrow on the body. They will leak if installed backwards. This one has no arrow but I still wonder.

Top line is input to pump, bottom line comes from tank and line at 9:00 is the antifreeze tube. I have reversed the top and bottom lines while re-plumbing for a new pump just to clean things up.

So anyone know definitively if these valves are directional or not?



BTW, new pump is a Seaflo. Avoid at all costs.
  • That is a standard 3-way valve

    Valve handle indicates direction of flow

    In-line like in the photo
    *water comes from fresh water tank and then goes to pump suction inlet

    Turn 90* ---handle towards anti-freeze line
    *Pump will suck anti-freeze and discharge it into RV Plumbing system
  • Old-Biscuit wrote:
    That is a standard 3-way valve

    Valve handle indicates direction of flow

    In-line like in the photo
    *water comes from fresh water tank and then goes to pump suction inlet

    Turn 90* ---handle towards anti-freeze line
    *Pump will suck anti-freeze and discharge it into RV Plumbing system


    Thx OB - I didn't really state my question very well. I'm familiar with what the valve does, I just need to know if the direction of flow matters. So if I leave the valve as shown and reverse the water flow going through it, does that cause any problems like it does with some brass valves?

    S
  • This looks like a ball valve. They are not directional with respect to the water flow direction--or, more precisely, the side with pressure when closed. It's gate and maybe globe valves where the pressure needs to be on the correct side to prevent leaking when closed.

    Edit: Check valves are also directional, for rather obvious reasons.
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    The valve has two positions. One is "Straight through" if by Reversing the flow you mean the valve handle was to the left side of the valve body and is now on the right. that will still work the same

    However the "alternative position will connect the antifreeze suction line to the tank line not to the pump inlet so that will cause an issue

    if by reverse you mean you swapped the tank side line with the antifreeze line. No it wont' cause an issue just make sure the valve points to the line you want to suck from.
  • The direction of flow of the water does not matter when not using the antifreeze suction tube. If you reverse the direction of the valve, instead of connecting the antifreeze suction tube to the RV's water lines, you just connect it to the fresh water tank and pump all of your antifreeze there.
  • Thx everyone. Drew had the answer I was looking for. It was some old gate valves that I ran into this issue with in ancient times.

    Thx to all who answered.

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