Hi-Force HP227D Manual

TDS1206 0711
Hi-Force Ltd. Tel: [phone] Fax: [phone]. www.hi-force.com
OPERATING AND MAINTENANCE INSTRUCTIONS
HP227D AND HP257D DOUBLE ACTING HAND PUMPS.
WARNING. Hi-Force hydraulic equipment operates at very high pressure!
Careful attention to the following safety precautions will help prevent personal injury.
DESCRIPTION: HP227D and HP257D are two speed hand pumps suitable for use with double acting
cylinders. Switching between low pressure and high pressure operation is done automatically
ensuring the pump always operates in the most efficient way.
GENERAL
1. All equipment used must be rated for the same operating pressure i.e. 700 bar (10,000 psi). DO
NOT mix high and low pressure components. If in doubt, contact your local Hi-Force Distributor.
2. Ensure that the pump has sufficient oil capacity to operate the cylinder(s) being used.
3. DO NOT exceed the rated pressure of the pump or rated capacity of the cylinder. Never tamper
with the internal safety relief valve of the pump.
4. Whenever possible use a pressure gauge in the system to prevent overloading.
5. ONLY use hoses in good condition that have a safety factor on burst pressure of 4:1 and are fitted
with strain relievers at each end.
TEST, EXAMINATION AND SERVICE.
1. Visually inspect all equipment before use for signs of damage or wear and tear. Any defective or
suspect equipment should be repaired or replaced immediately.
2. All high-pressure hydraulic equipment should be thoroughly examined and proof tested by a
competent engineer at least once a year - more frequently for heavy use.
3. Ask your Hi-Force distributor about the full Hi-Force Repair facilities and the Hi-Force Test and
Examination Service - available for all makes of high-pressure hydraulic equipment.
HOSE CONNECTION.
1. Hose connections are 3/8NPT and must be properly tightened using a quality pipe thread sealant
or 1-2 turns of Teflon tape taking care NOT to allow loose ends of the tape to enter the hydraulic
system. DO NOT over tighten connections - it can cause premature failure or rupture of fittings at
below rated capacity.
2. Connect the male couplers on the hose ends to the female couplers on the cylinder. Ensure that
both halves of the coupler are completely clean so that no dirt can enter the system. Fully tighten
the two halves of the coupler by hand only – do not use tools. It is not critical which hose is
connected to the advance port and which to the retract port of the cylinder, as long as a note is
made to avoid confusion. Danger: On a double acting cylinder both cylinder ports must be
connected to the handpump.

TDS1206 0711
Hi-Force Ltd. Tel: [phone] Fax: [phone]. www.hi-force.com
PUMP OPERATION.
1. The pump may be used either horizontally or vertically with the hose end downwards. Before use
unscrew the small bleed screw on the top of the tank. This will and maximise the oil volume
available. Tighten the bleed screw again before transporting the pump. The pump is equipped
with a pressure relief valve factory set at the maximum operating pressure.
2. To advance the cylinder, move the valve lever towards the hose outlet that is connected to the
advance port of the cylinder. Operate the pump handle.
3. To prevent accidental operation, centralise the valve lever when the cylinder is in the desired
position.
4. To retract the cylinder move the valve lever towards the hose outlet that is connected to the
retract port of the cylinder. Operate the pump handle.
5. WARNING: DO NOT RELY ON THE PUMP VALVE FOR POSITIVE LOAD HOLDING. IF IT IS
REQUIRED TO LOCK THE LOAD IN POSITION USE A MANUAL SHUT OFF VALVE OR
PILOT OPERATED CHECK VALVE IN THE CIRCUIT. NEVER WORK UNDER A LOAD
SUPPORTED ONLY BY HYDRAULIC MEANS.
FILLING WITH OIL.
Ensure cylinder is full retracted.
HP227D: Position pump vertically with pump head downwards. Remove central plug on rear of pump
and check oil level using dipstick fitted to plug.
HP257D: Position pump horizontal on a flat surface remove plug on the top of the tank and check oil
level with dipstick on plug.
BLEEDING THE HYDRAULIC SYSTEM.
Connect a cylinder to the pump. Position the cylinder below the level of the pump with its pressure
ports uppermost. Ensure the bleed screw on the pump is open. Operate the cylinder 3-4 times over
its full stroke and all air should be forced back to the pump reservoir. Warning: when using a small
cylinder with long hoses it is possible that air can remain trapped in the hose if the volume of the hose
is greater than the volume of the cylinder. In this case the bleeding must be carried out using a
shorter hose before use.