9-Way Valve Concept
I'm designing a product that has a need for an inexpensive low pressure
(<20psi) 9-way valve with orifices in the 1/8" range. This doesn't
seem to exist on the market, and custom brass bodied valves blow our
budget.
Something we are considering is making the valve body out
of delrin with a central reamed hole and 8 smaller holes radiating out
from it. Into that hole we'll press a stainless steel shaft with a
coaxial hole and a single radial hole that can be rotated to align with
the radial holes of the valve body.
The press will have to be
light to allow the shaft to rotate under hand pressure, but still tight
enough to form a good seal. The materials we are flowing are non
abrasive and the valve will be cycled on the order of 50k times in it's
expected life. Quantities will be ~5k.
Does this seem like a sane route to take? Is there an industry out there that regularly uses valves like these?
There is/was a radial n-way valve called, I think, a ScaniValve, or some
such, intended for multiplexing a single pressure transmitter or
sampling system among a bunch of sampled streams. They are normally
motor driven and cycle slowly.
Gas chromatography and high
pressure liquid chromatography use small plug valves made of PTFE, with
aluminum shells and stainless hardware. They
are normally hand operated with rather small handles. They are
commonly available with a variety of plugs, including 4-way 6-way and
8-way radial selectors. 9-way would be a special, but should be
achievable. One market leader is/was Hamilton. I have used them on an
OEM basis, driven directly by size 23 steppers, and gotten decent life
and tolerable pricing.
Do not underestimate the cost of
homebrewing this stuff; I have seen fortunes dissipated trying to make
small valves(needlevavle) on the cheap.
By "9-way" I mean 1 input and 8 possible outputs. I have no idea
whether that is correct terminology or not, I was just going along with
some data I had calling the 4 output valve we have a "5-way". Doesn't
make sense to me either.
Thanks for the pointer to
Hamilton. Their 8 port valve is what we need, but their pricing is
about an order of magnitude too high this product. I think I'll order
one to take apart and see if we can't engineer a lower performance/cheaper material version.
Therer exists on the market distribution 'lists' for solenoid valves
with a number of outputs, where any output may be either
blinded/plugged or closed with a removable hand operated needle valve,
or you can mount a solenoid valve to open one outlet at a time or
several at the same time. Inlet to the lists from one or both sides.
In this way you can have have at least a 9-way or higher number of outlets, with clearly defined on/off outputs.
Even
if this is available in SS, brass or aluminium, it seems that you are
looking for something smaller, more compact and cheaper than this.
Another way is of course to look for a combination of valves that are three- or fourway but with a common inlet.
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