| Operation
Flow enters the unit and makes a right angle to the outlet
port across the nose of a magnetic piston. The
piston is held in place by attraction to an adjusting
screw magnet. A pressure differential is created
by flow across the piston. When the differential
is great enough, the piston slides to a seat at
the outlet port. The flow rate at which the piston
actuates can be changed externally by turning
the adjusting screw, thereby changing the piston's
relationship with the flow stream.
In this auto reset model after actuation,
the piston rests on a metal to metal seat that
allows a controlled bleed. To reset the unit,
pressure must be equalized on both sides of the
piston. If the source is turned off, either upstream
or downstream, the bleed will equalize the pressure
and the valve will automatically reopen by magnetic
repulsion from the fixed magnet located in the
valve body.
For positive shut-off an elastomer
is used on the nose of the piston. When it comes
to rest on the seat it provides a bubble tight
closure. To reopen the valve there are two options.
-
The upstream pipeline must be
bled to atmosphere if the line downstream
is at atmosphere.
-
A by-pass line with an on/off
valve must be installed to port the upstream
pressure to the downstream pipeline to equalize
the pressure.
-
Actuation points for air at
68° F and 14.7 PSIG.
-
Corrections must be used for
other gases, line pressures and temperatures.*
-
Please consult your representative
or the factory.
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