Volume control in line between PB valve and shower head

Discussion in 'Shower & bathtub Forum & Blog' started by jkhome, Nov 5, 2004.

  1. jkhome

    jkhome New Member

    Messages:
    23
    For years I have had an in-line volume control on my shower nipple/head, when using a standard 3-valve tub/shower control. For water saving "submarine showers" (if you know what I mean). I usually got a little cross flow from cold to hot when turning back on from the off position of the volume control (water colder than normal). No big deal.

    I'm installing a new Kohler Forte Rite Temp system on a new tub/shower unit. Can I still have a volume control between the pressure balance valve and the showerhead? The manual recommends against this, but if I have the same results as before, should be no big deal.

    Also, what about installing check valves in the supply lines going into the PB valve? Would this help and should I go swing or spring?

    Thanks John
  2. jkhome

    jkhome New Member

    Messages:
    23
    Talked to the factory, they said not only would I have the cross flow problem, but also the PB valve would leak! So much for that idea.

    Asked them about putting a thermostatic valve in to feed the hot side of the pressure balancing valve, (teeing the cold to go to both). Basically using it as a hot water limit. Then I could turn the PB valve full hot or off, and get the same results. They didn't even want to go there!

    They explained that any pressure drop caused by the first valve, would cause the second to match it on the cold side. So how much pressure drop would a 1/2" thermostatic valve produce? Enough to choke the hot/cold water supply coming out of the PB to cause a problem?

    Sounding like it isn't going to be worth the trouble.
  3. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    If you notice my avatar, I do know what you mean about submarine showers. By the way, we had a shut-off at the shower head to conserve water, but it resulted in the backflow of cold into the hot line as you mentioned, which was a real bummer when you went to rinse off!

    PB valves are tricky, and any thing ahead or behind is likely to work against the balancing feature. If you need to control the flow somewhat, try an adjustable shower head. As far as water conservation, if the shower head itself is less than 12 years old, it must be a 2.5 gpm max already.
  4. jkhome

    jkhome New Member

    Messages:
    23
    Hey jimbo

    As per the factory, I went ahead and ordered a thermostatic valve and a seperate volume control valve, to use with the existing diverting spout and shower head. That should do what I want and give me better control.

    The supplied PB valve won't be used, on to the spare parts bin for another day.
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