NAARSO 2017 MCO Wire Rope 2017 MCO • Wire Rope is a working machine. • A wire rope has been...
Transcript of NAARSO 2017 MCO Wire Rope 2017 MCO • Wire Rope is a working machine. • A wire rope has been...
NAARSO 2017 MCO
NAARSO 2017
WIRE ROPEPresented by
C W Craven
Wire Rope Order
• 5000’ 1‐1/4” 6X19 Seale RRL XIPS PPC Bright
• Lube with Castor oil 1A or equiv.
• Must meet requirements of ANSI B77.1‐2014
• Minimum Breaking Strength of ……………
NAARSO 2017 MCO
• Wire Rope is a working machine.
• A wire rope has been selected / designed for a particular application.
– Diameter
– Breaking Strength
– Material
– Flexibility
Ab i R i t– Abrasion Resistance
– Other factors: Lay, Lay Length, Core, lube, Strand Construction, Corrosion Resistance, Economics.
• Wire Rope is made up of
3 Basic Parts
– Wire
– Strand
– Core
NAARSO 2017 MCO
Core Types
• Fiber Core
– Hemp/Sisal (FC) (outdated)
– Poly Propylene (PPC)
– Thermoplastic
• Wire Strand Core (WSC)
• Independent Wire Rope Core (IWRC)• Independent Wire Rope Core (IWRC)
• Custom / Combinations
Carbon Steels Used in Wire Rope
• The following terms have been around since the early days • of wire rope, when ropes were made to drag a plowshare thru the
fi ldfield.• IRON rope – Actually low carbon steel (obsolete)• TS – Traction Steel• EH – Extra High Strength Traction Steel• PS / MPS – Plow Steel / Mild Plow steel (obsolete)• IPS – IMPROVED PLOW STEEL (mostly larger diameters)• EIPS (XIPS or XIP) – EXTRA IMPROVED PLOW STEEL (standard)• EEIPS (XXIPS or XXIP) EXTRA EXTRA IMPROVED PLOW STEEL• Grades of plow steel wire rope strength increase by approximately
15% increments.• Stainless steel and other non ferrous metals are also used.
NAARSO 2017 MCO
Strand Construction
Larger wires = less flexibility / fatigue resistance but greater abrasion resistanceresistance but greater abrasion resistance.Smaller wires = more flexibility / fatigue resistance but has less resistance to abrasion.
Many more strand types, including compacted strands, rotation resistant, and lock coil. These are most common for FC rope.
Rope Classification
6 x 19 Classification ropes contain 6 strands with 15 through 26 wires per strand, no more than 12 of which are outside wires.i.e. a 6 Strand wire rope having 19 wires per strand.
NAARSO 2017 MCO
Rope Lay
RRL ‐ Right Regular Lay – Most Common
RLL ‐ Right Lang Lay
LRL – Left Regular Lay
LLL – Left Lang Lay
Lay Length
The distance 1 strand takes to make a complete revolution around the rope.(Usually measured and divided over several lay lengths)
A significant localized increase in the lay length after the rope has broken in needs to be investigated.
O ll l thOverall lengthSignificant changes in overall length (rate of stretch) after construction stretch has been removed are of concern.
NAARSO 2017 MCO
Corrosion Resistance and lube type
• “Bright” plain steel
• Galvanized, can be pre draw or post draw
• Stainless Steel or other metals
• Lubricants:
– Depends upon the application
– What is the rope going to interact with?
Application Standards
• Crane and Rigging Applications
– ASME B30
• Elevators
– ASME A17
• Passenger Ropeways
ANSI B77– ANSI B77
• Amusement Rides
– ASTM F‐24
NAARSO 2017 MCO
Wire rope maintenance
• Protect from damage
• Lubrication• Lubrication– Don’t over lube
– Use the proper lube, must be compatible with construction lubricant and items that rope comes in contact with. ie sheaves, liners, environmental concerns.
• Periodic InspectionRope (diameter and lay length checks visual inspection– Rope (diameter and lay length checks, visual inspection, MRT)
– Installation/Application• Don’t make the rope work harder than it’s needs to (shorter life)
Inspection
• External examination, MRT (ferrous ropes), d i t l i tiand internal inspections.
• What are we looking for?
– Fatigue / Damage / Abuse indications
– Application issues
– Broken wiresBroken wires
– Changes in length, lay length, or diameter
– Internal issues
NAARSO 2017 MCO
Inspection – Application Issues
• End connections:
– U bolt clips
• Installed correctly– Quantity, torque, spacing, orientation
– Fist grips (double saddle clip)
– Wedge sockets
– Crimped or swaged end connections
– Thimbles
U‐Bolt Clip Installation
NAARSO 2017 MCO
Wedge Socket Installation
Incorrect Correct
Inspection – Damage and Abuse
• Crushing
• Kinking
• Abrasion
• High Stranding
• Heat and chemical
• Improper application or use
NAARSO 2017 MCO
Inspection ‐ Broken Wires
• Outer wire breaks / Valley breaks• Localized damage / evenly distributedg / y• Cause?• Allowable number of allowable broken wires depends of
the following:– Application
• Crane & Rigging, Elevator, Passenger Ropeway, Amusement Ride, Etc.
– Location• In the splice area?In the splice area?• Adjacent to end connections?
– Quantity• How many?• How close to each other?
Allowable broken wires in a ropeway ANSI B77
• Broken wires in one lay length in excess of 7 ½% of the cross sectional metallic area of the rope or 25% of the metallic cross sectional area of one strand (localized damage), or
• Broken wires in five lay lengths in excess of 10% of the metallic cross sectional area of the rope (uniformly distributed damage). Broken filler wires are not counted.
• NOTE When calculating the number of broken wires• NOTE – When calculating the number of broken wires from the metallic cross sectional area, the results will be rounded down to the next whole wire.
• Ropeway mfg. may have more stringent requirements.
NAARSO 2017 MCO
Allowable broke wires
• Amusement Ride: As specified by the ride f tmanufacture.
• Elevators: See Elevator inspection code (ASME A17)
• Crane and rigging applications (ASME B30)
Length and diameter measurements
• Diameter measurement
6 strand rope = measure in 3 planes and at various locations then average the results. 8 strand = 4 planes
NAARSO 2017 MCO
Inspection – Internal issues
• Broken Wire ‐ Valley Break
• Rouging
• Core issues
Visual Inspections
OUTER WIRE BREAKS – CROWN BREAKS(FATIGUE)