Check Valve
I used one of these valves in a smoke system, but it did
not work well for that application. It might be fine in a
fuel system, but I don't have personal experience with
that usage.
The check function is provided by a plastic (nylon?) piece that
slides back and forth inside the aluminum barrel. There is no
spring holding it closed so it depends on reverse flow to move
the sliding element into the closed position, and pressure differential
to hold it there. The sliding element has several small (~3/32") holes
that the fluid must pass through in the forward direction. This may be
fine for low viscosity fluids (like avgas), but not as good for higher
viscosity fluids like smoke oil.
I don't know anything about the internals of the Andair valve (or the
one provided by Airflow Performance), so I can't comment on their
merits. Price is a factor in chosing components, but reliability and
durability are ultimately the most important for safety-critical items
like this. Unfortunately these characteristics are not always
directly correlated.
If it were my plane, I would stick with proven components in the fuel
system. I would only buy this check valve if I could find a testamonial
from someone who had flown with it for several years in a similar
fuel system.
- Dan Benua
EAA Tech Counselor
Repeat Offender
