BIFFI ALGA-EAC Series - MHP Hydraulic Manual Override Maintenance and Trouble Shooting; Operation; Manual Operation; Remote Operation

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Installation, Operation and Maintenance Manual
MAN 564_EAC Rev. 2 June 2020
Maintenance
Section 5: Maintenance
5.3 MHP Hydraulic Manual Override Maintenance
and Trouble Shooting
5.3.1 Operation
(see the attached operating diagram MAN 562-A)
The “MHP” hydraulic manual override and speed control unit is utilized, in connection with
the actuator hydraulic cylinder, for the manual operation and for the speed control during
the pneumatic operation of pneumatic double-acting actuators.
5.3.2 Manual Operation
Selected by the hand operated directional control valve (D) the operation (opening or
closing) to be performed.
Actuate the handpump (P).
The relief valve (Rm) prevents that the oil pressure delivered by the handpump exceeds
the set value so to not damage the valve or the actuator.
5.3.3 Remote Operation
To allow the actuator pneumatic operation the hand operated directional control valve (D)
has to be in its “REMOTE” control position: valve liver in its central position as shown by the
instructions plate.
Pneumatic operation
The oil ows from the hydraulic cylinder chamber, rear ange side, via the ow regulator
(Fa), the valve (D) and the ow regulator (FC), free ow direction, to the hydraulic cylinder
chamber, head ange side.
The exceeding oil volume, corresponding to the hydraulic cylinder piston rod, ows via the
ows regulator (Fr) into the oil tank (Ot).
The relief valve (Ra) prevents that the oil pressure, into the hydraulic cylinder, exceeds a
set value.
The ow regulator (Fa) allows the setting of the actuator operation speed in opening
independently from the actuator speed in closing.
Pneumatic closing operation
The oil ows from the hydraulic cylinder chamber, head ange side, via the ow regulator
(Fc), the valve (D) and the ow regulator (Fa), free ow direction, to the hydraulic cylinder
chamber, rear ange side.
The missing oil volume, corresponding to the piston rod of hydraulic cylinder, is sucked from
the oil tank via the check valve (Cv).
The ow regulator (Fc) allows the setting of the actuator operation speed in closing,
independently from the actuator speed in opening.