FUNDAMENTALS OF
CONVEYOR SYSTEMS
Presented by:
Rodney Roalsen, Rubber & Plastics
Laura Hoggan, Rubber & Plastics
Topics to be Covered
❧ System Maintenance
❧ Belt Maintenance
❧ Anatomy of a belt
❧ Common belts specifications and designs in Sand Fracking
❧ Are there additional Topics that you would
like covered?
Section I: System Maintenance
System Square
❧ A conveyor system frame is like a car frame, if your frame is not
square it will throw off other components, creating wear and tear.
❧ The Dragon Tail is the most susceptible area for being out of square,
check it often!
Cleaning
• Good system maintenance can be summed up in two
words, “Good Housekeeping”.
• Check pulleys and rollers for material build-up.
What happens if you load off-center?
❧ Catastrophic failure
❧ Damage to belt
❧ Tracking issues
Section II: Belt Maintenance
Belt Tracking/Training Considerations
❧ Conveyor belt moves toward the end of the roller/idler it contacts first
❧ Check conveyor system for structural misalignments
❧ Check pulleys and idlers for misalignment and build-up
❧ Check belt splice for accuracy and straightness
❧ Observe belt in operation empty and loaded for tracking tendencies
❧ Eliminate Spillage, Off-center loading and build-up of materials, factors that
cause tracking issues
Splice Failures
❧ Inspect lace to ensure all parts are still present
❧ Inspect Vulcanized splices for cracking, splitting and loose sidewall sections
Belt Repair
❧ Flexco® offers a variety of
rip repair fasteners. With
these you can patch soft
spots before they become
rips or a cut or tear in your
belt to extend your belt life
❧ Eli-Flex rubber repair kits
for holes, tears, splits,
gouges and excess wear
areas
What happens if I install the wrong belt spec?
❧ Belt will wear faster than expected
❧ Belt may potentially fail
❧ Cleats and/or Sidewall may separate
from belt
TO-DO LIST!
❧ Follow OEM guide for lubrication
schedule
❧ Visually inspect:
❧ Rollers, Pulleys, Return rollers & belt
guides for excessive wear, built up material
and damage.
❧ Belt Splice for wear on lace, cracks,
missing components.
❧ Sidewall for damage and missing sections
❧ Inspect belts:
❧ Tracking properly
❧ Tension
Section III: Anatomy of a belt
Belt Specification Breakdown
❧3 = Number of Tension
Plies
❧2 = Number of Cross Rigid
Plies
What is a Ply?
❧ A rubber coated layer of fabric
❧ Each “carcass” layer is a ply
❧ Commonly a Polyester/Nylon
material
❧ Are the strength member of the belt
How do you know how many plies you have?
❧ Count the number of layers of fabric visible in the belt
CROSS RIGID BELT
❧ Engineered for applications that
take a sharp upturn, with a heavy
cleat and/or corrugated sidewall.
❧ Cross Rigid belts are rigid across the
belt (fill or weft direction)
❧ Provides lateral reinforcement that
keeps the belting rigid
❧ Cross Rigid belting will withstand
deflection from horizontal to
incline without bowing or sagging
during operations.
Belt Specification Breakdown
❧ 3 = Number of Tension Plies
❧ 2 = Number of Cross Rigid Plies
❧330 = Working tension per inch width
Working Tension
❧ Working tension is a factor of the fabric/ply
❧ Rated on a per inch width
❧ Fabric strength has a direct impact on minimum pulley diameter
requirements
Why does it matter?
❧ Belt will snap in operation if not rated for the tension of the system
Belt Specification Breakdown
❧ 3 = Number of Tension Plies
❧ 2 = Number of Cross Rigid Plies
❧ 330 = Working tension per inch width
❧1/8 = Thickness of Rubber top cover
Top Cover Thickness
❧ Provides an impact and abrasion resistance layer, protecting the belt fabric
❧ There are standard cover thicknesses which vary based on the plies and
tension rating of the belt
❧ Custom thicknesses are available but usually require a minimum quantity
purchase
Belt Specification Breakdown
❧ 3 = Number of Tension Plies
❧ 2 = Number of Cross Rigid Plies
❧ 330 = Working tension per inch width
❧ 1/8 = Thickness of Rubber top cover
❧1/16 = Thickness of Rubber bottom cover
Bottom Cover of a Conveyor Belt
❧ May have a rubber bottom or a “bare-back” bottom
❧ PVC belts are:
❧ COS = Cover one Side
❧ CBS = Cover both sides
❧ Rubber Belts are:
❧ Called out by actual thickness of cover materials
What is a “Bare-Back”?
❧ A conveyor belt with no bottom rubber cover
❧ Bottom of conveyor belt is the fabric from the bottom ply
Why use a “Bare-Back”?
❧ Slider Bed Applications
❧ Fabric bottom has a lower coefficient of friction than a Rubber bottom
Belt Specification Breakdown
❧ 3 = Number of Tension Plies
❧ 2 = Number of Cross Rigid Plies
❧ 330 = Working tension per inch width
❧ 1/8 = Thickness of Rubber top cover
❧ 1/16 = Thickness of Rubber bottom cover
❧ MOR / Grd II = The type of Rubber Material used in
the belt
What Rubber Compounds are common?
RMA GRADE 2
MOST COMMON
COMPOUND
GREAT FOR ALL GENERAL
MATERIALS AND
PRODUCTS
GOOD IMPACT AND
ABRASION RESISTANCE
RMA GRADE 1
MAINLY FOR HIGH IMPACT,
CUTTING AND ABRASION
APPLICATIONS
MORE NATURAL RUBBER
BEST IMPACT, ABRASION
AND GOUGE RESISTANCE
MOR
MAINLY FOR ANY
APPLICATION WHERE OILS
WILL BE PRESENT. IS
MODERATELY RESISTANT
TO OILS AND SOLVENTS
Section IV: Common Belt Specifications and
Designs in Sand Fracking
Profile Belts
❧ Why use a profile belt?
❧ Inclines greater than 20°
❧ To prevent roll back of material
❧ Common Profiles
❧ Herringbone
❧ Chevron
❧ V-Cleat
❧ MaxClimb
❧ MegaClimb
Sand Frack Belt Configurations
Sidewall Belt; No cleats
❧ Typically on Sand Delivery Units
❧ Sand Delivery Units handle frack sand
that is transported to frack sites in tractor
trailers.
❧ Uses a combination of hoppers and
conveyor belts to move frack sand to the
T-Belt during fracking operations.
❧ Operates on Troughing Idlers
Details:
❧ Sidewall height
from 2” to 4”
❧ Available on any
belt specification
Sand Frack Belt Configurations
Narrow Width MaxClimb w/ Sidewall
❧ Typically on the T-Belt (Dual Belt Units)
❧ Takes discharge from multiple Sand Delivery
Units and delivers to the blenders.
❧ Compartmented belt allows for high angle
discharge of materials.
Details:
❧ 30” and Narrower belts
❧ 1-1/4” tall cleats
❧ Sidewall heights of 2” to 6”
Sand Frack Belt Configurations
MaxClimb w/ Sidewall
❧ Typically on the T-Belt (Single Belt Units)
❧ Takes discharge from multiple Sand
Delivery Units and delivers to the
blenders.
❧ Compartmented belt allows for high
angle discharge of materials.
Details:
❧ 30” and Wider belts
❧ 1-1/4” tall cleats
❧ Sidewall heights of 2” to 6”
Sand Frack Belt Configurations
3” Peg Belt w/ Sidewall
❧ “Peg” or “Finger” Belt
❧ Conveys continuous flow of material
❧ Powder to moderate lump sizes
❧ Up to 45° Angles
❧ High material capacity
❧ Can be on Delivery Units or T-Belt Units
Details:
❧ 24” Wide (Peg pattern is 20“ wide)
❧ Available on any belt specification
❧ Pegs are 70 durometer
Belt End Preparation
Hot Vulcanized
Super Screw
❧ Custom peg mold to vulcanize splice
area w/ Pegs and hot vulcanize
sidewall
❧ Mechanically fastened to belt
❧ Sidewall finger molds to hot vulcanize
sidewall at splice area
❧ Reduces the installation time and
tools required
❧ Sidewall is installed at the factory as
an Easy Over splice
Sand Frack belts require prepared
ends to prevent the loss of material.
Frack Sand can corrode and wear
down metal fasteners that are not
protected with a rubber cover.
❧ RPI can install one end to expedite
field installation
How do I know what belt to use?
❧ Belt selection is based on;
❧ Minimum pulley diameter
❧ The configuration of the conveyor system including;
❧ Type & Style of return
❧ Incline
❧ Changes in incline
❧ Slider bed or troughed rollers
❧ Overall length
❧ Height of incline
❧ Weight of material
Can I change Styles of Frack Belts?
❧ For the most part, Yes.
❧ Ensure new belt configuration fits the system, checking the following:
❧ Sidewall Height
❧ Cleat clearances (recess, height, etc.)
❧ Belt configuration may alter the speed at which a belt operates to deliver
the same tonnage per minute.
Sand Frack Environmental Concerns
• Small Pulley Diameters
•
Small pulley diameters put chemical bonds under stress, causing pre-mature failure
• Extreme Environments
•
Extreme cold in South Dakota, Pennsylvania, Canadian markets
•
Cold temperatures degrade the chemical bond, causing pre-mature failure
•
Hot vulcanized sidewall is lasting 2-3x longer than Chemical bonds
• Field Location Difficulties
•
Timeliness to get to breakdown area
•
Exposure to environment
•
Potential lack of equipment / power sources
How to determine quality of a belt
❧ Import vs. Domestic
❧ Location of manufacturing doesn’t matter, the quality does.
❧ Safety Factors
❧ Ply Adhesion
❧ Elongation
❧ Quality of Value-Add Process;
❧ Key term: Hot Vulcanization
Questions??
Presented By:
Rodney Roalsen, Rubber & Plastics
Laura Hoggan, Rubber & Plastics