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.

The existing flow control valve may be

removed by hand, or with a 5/16” nut

driver. (see below)

Turn CCW to remove brass air hose fitting

Cut both hoses close to fittings at 90 degree angle