Safety Precautions

Safety Precautions for Double-Acting Telescopic Cylinder

Warning!

Rollover or lateral tilt can cause severe injury or death and/or damage to the unit and cylinder.

• The hydraulic cylinder will not prevent the unit from rollover or lateral tilt. The cylinder is strictly a lifting device and is not a structural member of the unit. Cylinders are not to be used as a means of  stabilizing the unit. 
• The hydraulic cylinder mounted in the unit should be free to find its own trajectory line of extension and retraction so as not to cause improper sequencing and excessive wear to the plungers and  internal components. Misalignment could cause the unit to upset. On longer stroke cylinders mounted horizontally, supports should be added to the center of the extended cylinder to increase the column strength of the cylinder.
• The hydraulic cylinder will not withstand lateral pressure when the unit is leaning. Only activate the cylinder when the tractor and trailer are in a straight line (not jack-knifed). Do not activate the cylinder while on unlevel or soft ground, or during heavy crosswinds. Doing so may cause the unit to upset.
• Do not activate the cylinder while personnel or equipment are alongside or behind the unit.
• On roll-off units, if the container is not loaded evenly, the lift cylinder(s) may mis-stage which could cause the unit to upset and/or damage the cylinder when the plungers attempt to correct themselves.
• On roll-off units, lower the container with the control valve partially open (avoid lowering the container with the control valve completely open) to prevent pressure build-up in the reeving cylinders as gravity pulls the container to the ground.

WARNING!

Shock pressure can cause severe injury or death and/or damage to the unit and cylinder.

• Do not extend the cylinder until it has been fully retracted. A partially extended cylinder with pressure relieved may drift out of position. When the cylinder is later extended, the out of position plunger will reposition rapidly and possibly cause high pressure trapped oil on the retract side of the cylinder.
• On roll-off units, do not pull a container onto the hoist until the lift cylinder(s) are completely extended. On roll-off units, care must be taken if a unit is moved with the lift cylinders extended. Avoid sudden stops or jolts.
• Check the cylinder operation to ensure the plungers extend in sequence with the largest diameter plunger moving first, then the next largest, etc. When retracting, the smallest plunger should move first, then the next smallest, etc. Mis-staging could cause the unit to upset and/or damage the cylinder due to excessive pressure build-up.

WARNING!

Over pressurizing the cylinder can cause severe injury or death and/or damage to the unit and cylinder.

• Do not operate the cylinder at pressures greater than the pressure indicated on the cylinder name plate unless otherwise approved in writing by Custom Hoists, Inc.®
• Hydraulic hoses should be checked regularly and replaced if worn out or damaged.

NOTICE!

• Do not operate a packer/ejector cylinder with a mis-aligned blade. This can cause excessive lateral loading to the cylinder which could cause internal damage.
• If the hydraulic system uses quick disconnects or holding/lock type valves, make sure they are properly connected.  If not, oil may become trapped in the cylinder which could cause internal damage.
• A double-acting telescopic cylinder normally requires at least 15 G.P.M. oil flow to retract properly. Make sure the hydraulic pump is developing the required flow.
• Most double-acting telescopic cylinders will bleed themselves of air. On a new cylinder installation, cycle the cylinder approximately ten times to the complete extend and retract positions with no load against it to remove the entrapped air.  
• The hydraulic oil should be checked and changed regularly to avoid contamination leading to internal cylinder damage. For hydraulic oil recommendations 
• Grease the pin mountings regularly.