pressure. The double-acting cylinder shown in figure
4-11, view B, is called an unbalanced cylinder. This
means that the cylinder can exert more force in one
direction than in the other. This is due to the piston rod
preventing fluid from acting on the full area of the piston
on one side.
NOTE: Wipe off all foreign material from
hydraulic rams with a clean rag during pre- and
post-operations to prevent damaging seals and wiper
seals. Before you store equipment, a very important
procedure to remember is that the exposed hydraulic
rams on the equipment and attachments should be
coated in grease. This action protects the surface of the
hydraulic ram and is critical in storage locations where
corrosive environmental conditions, such as salty air,
strong winds, or blowing sand, exist.
Remember: Wipe off the grease before using the
equipment when it is removed from storage.
Flexible hoses are used in a hydraulic system to
allow movement between mechanical parts of the
Figure 4-11.(A) Single- and (B) double-acting hydraulic cylinders.