Service manual

Flow Control Valve Replacement (part # 12-816)

This procedure covers replacement of the earlier flow control valve with the current

version, or replacement of a damaged or defective valve. It is recommended that you

replace the original brass nipple air fitting with one of the current “quick disconnect”

fittings at the same time. (part # 12-817)

1) Disconnect the main air hose from the pneumatics panel on the rear of the machine,

or from the air compressor. Raise the cutting head up at least a foot on the gantry

beam to make it more accessible. Shut down the machine or push in the Emergency

Stop knob.

2) Remove the cover plate from the cutting head by removing the three screws with a

1/8” Allen wrench. Unplug the C-axis motor and Home sensor connectors to avoid

damage to the wires.

3) If you are replacing

one of the early-type

flow control valves,

you may remove the

black and clear air

hoses from the brass

fittings by cutting the

hose as close to the

brass nipple as

possible. Use care to

cut the hose with as

close to a 90 degree

cut as possible. (see

photo)

4) Using a ¼” nut driver, unscrew the small brass fitting from the cutting head. Make

sure that you are turning the nut driver counter-clockwise as viewed from below.

Turning the tool in the incorrect direction may result in breaking the threaded portion

of the fitting or valve off inside the cutting head casting. Using a 5/16” nut driver, (or

by hand), unscrew and remove the existing flow control valve from the cutting head

as well.

Cut both hoses close to fittings at 90 degree angle