Gradall 544D (9136-4003) Service Manual - Manual (Page 99)

Standard Buna-N Seals and O-Rings
All standard Gresen products utilize Buna-N seals
which are compatible with petroleum base, water-in-
oil emulsions, and water-glycol. Phosphate ester type
fire-resistant fluids will cause Buna-N seals to swell.
This swelling is not normally detrimental to static seals,
it will be a problem for dynamic seals such as valve
spool seals. Swelling of these seals can result in bind-
ing. The temperature range of Buna-N seals is -40°F to
+200°F (-40°C to +93°C) for continuous operation.
Optional Viton Seals and O-Rings
Viton seals are recommended for most applications
that use phosphate ester type fluids. Viton seals are
also recommended for applications that have a con-
tinuous operating temperature of +200°F (+93°C) or
more. For information on Viton Seals for Model V40
Control Valves, contact the factory.
Table 4-1. Port Plugs and Seals.
4-29