Owner manual

IMPORTANT RECEIVING INSTRUCTIONS: Visually inspect all components for shipping damage. If any
shipping damage is found, notify carrier at once. Shipping damage is NOT covered by warranty. The carrier is
responsible for all repair or replacement cost resulting from damage in shipment.
Carefully plan your system by selecting components designed to perform the intended operation and which will
adequately perform with existing equipment. Always check the product limitations regarding pressure ranges,
load capacities and set-up requirements. The system operating pressure must not exceed the pressure rating of
the lowest rated component in the system. Read all CAUTIONS, WARNINGS, and INSTRUCTIONS included
with, or attached to, each product. Follow all safety precautions to avoid personal injury or property damage
during the system operation. ENERPAC CANNOT BE RESPONSIBLE FOR DAMAGE OR INJURY
RESULTING FROM UNSAFE USE OF PRODUCT, LACK OF MAINTENANCE OR INCORRECT PRODUCT
AND SYSTEM APPLICATION.
Contact ENERPAC when in doubt as to safety precautions, or applications.
SAFETY FIRST
L-1730 3/92
Instruction Sheet
V - 42 / V - 44 PILOT-OPERATED
CHECK VALVE
Pilot-operated check valves are used with cylinders for
temporary load holding.
Cribbing and blocking should be used for
extended periods of load holding. Without
cribbing or blocking, no one should attempt
to go under load.
Installation (see diagrams, page 2)
Install "tee" between retract port of cylinder and cylinder
half coupler. Install p.o. check as close to cylinder as
possible to eliminate potential leak points. Cylinder,
pump and pilot port identification marks are stamped into
valve bodies. Install p.o. check valve between advance
port on cylinder and cylinder half coupler. Install tubing
between "tee" in retract port and pilot port on p.o. check
valve. One-quarter inch O.D. steel tubing, with minimum
wall thickness of .049" should be used. Tubing should
be rated at a minimum 20,000 psi burst pressure.
Operation
When flow is directed to the advance side of cylinder, oil
will flow through p.o. check valve and raise cylinder
plunger.
When flow is directed to the retract side of the cylinder,
pilot pressure is supplied to the check valve. This
causes the ball check to unseat and allows flow from the
advance side of the plunger to return to the pump
through the advance line. The V42/44 have 6.5:1 ratio
system pressure to pilot pressure.
Example: With 5,000 psi on the advance side of the
cylinder, it will take approximately 800 psi to open the
p.o. check and allow the cylinder to retract.
Note: On systems with slow cylinder speeds due to
pump flow rates, cylinders may not retract smoothly.
This is caused by the low flow of the pump not
maintaining pilot pressure. In this case a ‘meter-out’
valve will resolve the problem. A valve, such as a V-66,
installed in the advance line and partially closed would
restrict flow out of the advance side of the cylinder, and
allow pilot pressure to be maintained.
Cylinder must be on a firm foundation to
prevent the p.o. check valve from being
damaged.
WARNING
WARNING