Wood’s Powr-Grip VL3000L - Manual (Page 16)

Rev 11.0/7-13 14 VL3000: #35161
V
ACUUM
P
AD
M
AINTENANCE
Friction Coefficient
The friction coefficient represents the lifter's ability to resist load slippage when the load is
oriented in any position except horizontal. If the contact surfaces of either the load or the
vacuum pads are not clean, dry and in good condition, slippage is more likely to occur.
The Load Capacity of most Powr-Grip lifters is based on a friction coefficient of 1 (only Flat Lifters
are exempt from this requirement). However, a vacuum pad's ability to maintain this friction
coefficient is reduced by factors such as contamination, wear, age and exposure to sunlight, as
well as the condition of the load's contact surface (see INTENDED USE: L
OAD
C
HARACTERISTICS
).
Pads that have surface contamination must be thoroughly cleaned (see Cleaning discussion to
follow). Over time, the rubber in a pad may experience hardening or leaching of chemicals,
resulting in stiffness or surface glaze. Pads that exhibit wear, stiffness or glaze must be replaced.
In addition, all pads should be replaced on a regular basis, preferably after no more than 2 years,
to ensure that the friction coefficient is not compromised. If necessary, contact your dealer or
Wood's Powr-Grip for more information.
Inspection
Inspect each vacuum pad for the following deficiencies routinely, as directed in the preceding
I
NSPECTION
and T
ESTING
S
CHEDULES
. Correct any deficiency before using the lifter.
• Contaminates on the pad face or sealing edges: Soil build-up can prevent pads from sealing
adequately or reduce the friction coefficient (see discussion preceding). Follow the directions
to clean pads as necessary (see discussion to follow).
• Air filter missing from pad face: This filter helps prevent debris from contaminating the vacuum
pump. Replace any missing filter immediately (see hand cup instructions).
• Nicks, cuts or abrasions in sealing edges: Pad damage can reduce the lifting capacity of the
lifter. Replace any damaged pad immediately (see hand cup instructions).
WARNING: Replace vacuum pad if sealing edge has any nicks, cuts or abrasions.
• Wear, stiffness or glaze: See Friction Coefficient preceding. Replace any pad that exhibits
wear, stiffness or glaze (see hand cup instructions).