"MiamiCuse" wrote in message
...
I have a Grohe pressure balance shower/tub valve (model Grohesafe 35 253
000). My plan is to plug the lower outlet port, and only use the top
outlet.

The top outlet (1/2") will come off the valve to a 5 port diverter (Grohe
29 714). This diverter has two inlets and three outlets, since the water
is already mixed, I will plug one of the inlets.

The three outlets - two are 1/2" and one 3/4". I will route one line to
an overhead shower, one line to a handshower wall union/elbow, and the
3/4" to a "T" which splits off to two 1/2" lines each terminating on a
body jet spray. So basically a valve runs to a diverter, then the
diverter transfers the flow to an overhead shower, or a handshower or two
sprays.

In reading the specs for the valve it says it delivers 6.8 gpm, and the
sprays are 2.5 gpm each, so for two it will take 5 gpm, we should be ok,
unless I want to use the handshower or overhead shower at the same time
which is impossible since the diverter only transfer the flow to one of
the three outlets, it does not mix.

So I called up Grohe technical support and presented this over the phone,
and the guy says "you cannot use pressure balanced valve with sprays it's
not strong enough you need more gpm". I said since the diverter does not
allow you to transfer flow to more than one port at a time, if I have 6.8
gpm going into two devices at 2.5 gpm shouldn't it work?" he said no, just
thermostatic valves must be used for sprays. I asked why the pressure
balance valve at 6.8 gpm is not enough he said what if you want to run the
overhead shower and sprays at the same time, I asked him is this possible
with the diverter he said no, that the diverter was designed to use one
port only at one time, he couldn't answer. He said I also need to use
volume controls instead of diverters, that the diverter will hinder the
pressure and flow volume - I do not understand again, Grohe's diverter
just transfer flow, at the end of the day it looks like a bent pipe inside
the diverter, not any less efficient than a 90 degree elbow in the copper
line.

So I would like to ask those who knows, is 6.8 gpm enough to deliver flow
to two spray jets rated at 2.5 gpm each?

Thanks,

MC


Might be. Shouldn't be very hard to rig it up and test. I chose to install
a valve for each outlet on mine. Valve may allow 6.8 gal to pass thru but
not at high enough pressure to be useable. Probably gives 2.5 gallons with
pressure for a shower head and 6.8 gallons with no pressure for the tub
spout. I wouldn't ignore Grohe's advice without testing first.