Pressure Relief Valve; Work Circuits - Wittke STARLIGHT Maintenance Manual

Figure 7-31 Work sections of the main valve (left-side mounted)
Top door
Tailgate
Arms
Forks
Packer

Pressure Relief Valve

The pressure relief valve is fitted in the inlet section of the valve bank and protects the hydraulic
components from damage caused by loads in excess of 2500 psi (S
F
EATHERWEIGHT
valve, the oil overcomes the adjustment spring and opens the relief valve allowing oil to return to the
tank.

Work Circuits

The circuits are listed from top to bottom in the same order as they appear in the valve bank assembly.
N : The following list is for the commercial front loader only.
OTE
 Hopper Top Door Circuit: The hopper top door circuit includes one double-acting hydraulic
cylinder and two flow restrictors.
 Tailgate Circuit: The tailgate circuit consists of two double-acting hydraulic cylinders, one
holding valve and two flow restrictors.
 Arms Circuit: The arms circuit consists of two double-acting cylinders and a deceleration valve
(a second deceleration valve can be installed on the circuit as an option).
 Forks Circuit: The forks circuit consist of two double-acting cylinders.
 Pack/Return Circuit: The pack circuit consists of two double-acting, 3-stage cylinders and a
pilot-operated check valve.
™) or 2750 psi (S D
UPER UTY
L
TAR
™). When pressure exceeds the setting of the relief
Hydraulic System 111
™ and
IGHT