Hydraulic Control Piping Assembly
The hydraulic control piping assembly (fig. 5-6)
consists of the control valves (stack valves), hose
connections, and associated piping and fittings.
Hydraulic fluid is provided to the JBDs by an inlet line
and shutoff valve connected to the main catapult
hydraulic system. The inlet branches off into three lines
(Mk 7 Mod 0/2) or two lines (Mk 7 Mod 1) with each
line connecting to a stack valve. The stack valve
controls the flow of hydraulic fluid to and from the
hydraulic cylinders. Emergency-lowering bypass lines
and valves are connected to the raising side of each
cylinder and to the gravity tank return lines. The bypass
lines permit routing of fluid around the stack valve and
are only used during an emergency situation to lower
the JBD panels.
An orifice assembly is provided in the line to the
raising side of the hydraulic cylinders which maintains
control of fluid flow for both the raising and lowering
sequence. Shutoff valves are located in each line of the
hydraulic cylinders for emergency and maintenance
purposes. Hose assemblies provide a flexible con-
nection between the hydraulic cylinders and piping to
compensate for movement of the cylinders during
raising and lowering operations.
REFER TO VIEW D
TO GRAVITY TANK
FROM CATAPULT HYDRAULIC SYSTEM
VALVE (STACK VALVE)
REFER TO VIEW C
EMERGENCY LOWERING BYPASS
CYLINDER PORTS A AND B
Figure 5-6.Hydraulic control piping assembly.