from the reservoir, through the system, and back to the
An air vent allows the air to be drawn in and pushed
out of the reservoir by the ever-changing fluid level. An
air filter is attached to the air vent to prevent drawing
atmospheric dust into the system by the ever-changing
fluid level. A securely fastened filling strainer of fine
mesh wire is always placed below the system filler cap.
The sight gauge is provided so the normal fluid level
can always be seen, as it is essential that the fluid in the
reservoir be at the correct level. The baffle plate
segregates the outlet fluid from the inlet fluid. Although
not a total segregation, it does allow time to dissipate the
air bubbles, lessen the fluid turbulence (contaminants
settle out of nonturbulent fluid), and cool the return fluid
somewhat before it is picked up by the pump.
Reservoirs used on CESE may vary considerably
from that shown in figure 10-23; however, manu-
facturers retain as many of the noted features as
possible, depending on design limits and use.
Hydraulic accumulators are incorporated in some
hydraulic systems to store a volume of liquid under
pressure for subsequent conversion into useful work or
to absorb rapid fluid pulsations when valves are
operated repeatedly. Two types of accumulators are the
spring operated and the air operated.
In this type of accumulator, the compression
resulting from the maximum installed length of the
spring or springs should provide the minimum pressure
required of the liquid in the cylinder assembly. As liquid
is forced into the cylinder (fig. 10-24), the piston is
forced upward and the spring or springs are further
compressed, thus providing a reservoir of potential
energy for later use.
The air-operated accumulator is often referred to as
a pneumatic or hydropneumatic accumulator. This type
of accumulator uses compressed gas (usually air or
nitrogen) to apply force to the stored liquid. Air-operated
accumulators are classified as either nonseparator or
Figure 10-24.-Spring-operated accumulator.
NONSEPARATOR TYPE OF ACCUMU-
LATOR. In the nonseparator type of accumulator
(fig. 10-25), no means are provided for separating the
gas from the liquid. It consists of a fully closed
cylinder, mounted in a vertical position, containing a
liquid port on the bottom and a pneumatic charging
port (Schrader valve) at the top.
Figure 10-25.-Air-operated accumulator (nonseparator type).