F
OR
M
ODELS
: JGI, JGM, JGN, JGP
AND
JGQ
S
ECTION
5 - M
AINTENANCE
PAGE 5-40
4.
With the retainer still in place, screw a valve puller tool over the valve center
bolt. See Figure 7-1 on page 7-2.
5.
It may be necessary to loosen the plastic thumb screw retainer-keeper in the
valve retainers.
6.
For high pressure applications that use a metallic gasket seal, the cylinder will
vent when cap screws are first loosened.
7.
Now the valve and retainer can be pulled out together. For cylinder class
1-3/4JG-FS-HE and 2-1/2JG-FS-HE tandem cylinders, the suction and dis-
charge piping and cylinder head must be removed to gain access to the concen-
tric valve. A concentric valve combines the suction and discharge valves in one
assembly. See Caution at “Piston and Rod” on page 5-27.
8.
In most cases the flat metal gasket will remain in the pocket. It is difficult to see.
A flashlight and a small mirror on an adjustable rod are the best tools to see the
gasket clearly. On cylinders with horizontal valves, the gasket may fall into the
gas passage. A small magnet on a flexible extension rod will help fish it out. This
gasket should be replaced if damaged.
Valves - Maintenance
Ariel uses valves manufactured by Hoerbiger Corporation. Before servicing any valve refer
to the correct valve assembly drawing and parts list and Hoerbiger's literature in the Ariel
Parts Book. On the valve assembly drawing you will notice that valves have different spring-
ing for different pressure levels. The cylinder cover sheet in the Parts Book lists the valve
originally supplied with each cylinder. If different operating pressures are encountered, then
different springs may be required.
The suction valve must be selected on the basis of operating suction pressure and the dis-
charge valve for operating discharge pressure. Proper valve spring selection is also based
upon the operating speed (RPM), gas specific gravity and the suction temperature of the
gas.
Contact Ariel in Mount Vernon, for assistance in valve selection.