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5
I-4.
Braze the stub-out portion to the liquid line and let cool.
I-6.
Tighten the nut to a torque of approximately 10-30 ft-lbs. Do NOT
overtighten the nut. Overtightening will impede the piston movement
during operation.
I-5.
Taking care that the white
Teflon seal is still in place inside
the flowrater body, firmly seat the
stub and screw the attachment
nut to flowrater body.
O-ring
During some installations, a piston change may
be required. If so, the installer
MUST
change the
piston. Use piston sizes recommended by the
outdoor unit manufacturer. If a sizing chart is not
available, use the piston size chart provided be-
low to size the required piston. The size of the
piston is stamped on the piston body (Fig 8A-2).
II. Piston Replacement
Fig 8A-2
Use the chart below when matching coil with an outdoor unit with a
different nominal capacity than the coil.
Note: Photos are for basic illustration purposes only. Actual equip-
ment configuration may differ from that shown.
II-4.
Slide the 13/16” nut over
the lineset and separate the two
halves of the flowrator.
Be aware of the Teflon O-ring. Be sure to
replace the O-ring to attain a proper
seal. (The Teflon O-ring is located between
the two halves of the flowrator)
CAUTION
!
Pay close attention to the piston orienta-
tion. The pointed end of the piston MUST
go into the distributor body, towards the
coil. Failure to ensure this orientation will cause the piston
to be bypassed during operation which might damage the
outdoor unit.
CAUTION
!
II-6.
Replace the piston with one
of the correct size. Do not force
the new piston into the body.
Make sure the piston moves
freely in body.
II-1.
Evacuate the system as per manufacturer guidelines and rec-
ommendations
II-2.
Turn the 13/16” nut once to release any residual pressure in the
coil.
II-3.
After ensuring that the coil
is free of any residual pressure,
disassemble the flowrator body
completely using two wrenches.
Take great care not to distort the
feeder tubes. The wrench used
to clasp the nut should be turned
in counter-clockwise direction to
unscrew the nut.
II-5.
Pull the piston out using a
small wire or pick. Verify the pis-
ton size (size is typically stamped
on the body of the piston - Fig
8A-2). If a different piston size
is required by the outdoor unit
manufacturer, replace the piston
using the small wire provided with
the piston kit.
II-7.
Assemble the two halves correctly and ensure that the white
Teflon O-ring is present between the two halves (See I-5). Slide the
13/16” nut onto the distributor body.
II-8.
Tighten the nut to a torque of approximately 10-30 ft-lbs. Do NOT
overtighten the nut. Overtightening will impede the piston movement
during operation.
II-9.
If present, slide the rubber grommet back to position to prevent
air leakage.
8B. TXV Coils
Fig 8B-1. Components of a typical TXV assembly