Strengthening of Nuclear
Buried Piping Systems CFRP
Presented by:
Scott. F. Arnold, PE – Fyfe Company
Neda Stoeva, PE – JD Stevenson and Associates, Inc.
Overview
• Tyfo® Fibrwrap® Materials
• Research & Development
• Installation Method
• Case Studies
• ASME B31.1 Design Considerations
Wet Lay Up Installation
Cutting Fabric Mixing of Epoxy
Stress-Strain Relationship
E, modulus:
• 60ksi steel, E = 29,000ksi
• Carbon Comp. = 11,900ksi
• Glass Comp. = 3,000ksi
“Aerospace” grade Carbon Fiber Composite:
• ult. stress = 175ksi
• ult. strain = 0.0027
• modulus = 65,000ksi
Full-Scale Column Test at UCSD
Beam-Slab Testing
Pipe Specific Research & Development
Internal and External Load Testing, Durability Testing
CFRP System Test Program for PCC-2
Burst Tests
Notable Buried Pipe Testing
• ASME PCC-2 – Spool Survival Test - Pressure
durability & In-plane shear testing
• ASME PCC-2 – Burst Pressure Tests
• ASME PCC-2 – Pressure Cycle Testing
• Groundwater Infiltration Prevention
• Watertightness
• Environmental Durability and Arrhenius
Modeling of Long-Term Design Properties
• Joint Repair Testing
FRP Codes-Reports-Design Guidelines
Code/ Report Issued by Date
ICC AC125 ICC (International Code Council-
California USA) Mar-10
ACI 440 ACI (American Concrete Institute) Oct-08
AWWA C304-04 Prestressed Concrete Pressure
Pipe, Steel Cylinder Type Dec-07
AWWA M11 Steel Water Pipe - A Guide for
Design and Installation Jul-04
ASME PCC-2 Repair of Pressure Equipment and
Piping Apr-11
ASME B31.1 Power Piping (ASME Code for
Pressure Piping, B31) Jun-12
Pipe Construction:
Any type of pipe including PCCP,
Steel, Aluminum, Ductile Iron,
RCP, FRP pipe, CIPP liner.
Diameter Range:
30in to 20ft+ diameter for internal
applications
Any diameter for external applications
Pressure Range:
Up to 400+ psi
Additional Loads:
Soil depths 35 ft+
HS20 loading
Vacuum loading
Technical Envelope for Fibrwrap Strengthening of Pipelines
Design Parameters
Loading Conditions
• Internal Pressures: (Design pressure, transients,
vacuum)
• Vertical Loads: (HS-20 loading, rail traffic loads,
soil, groundwater, special superimposed loads)
• Ovality considerations
• Longitudinal Loads: (thrust, temperature changes)
Fiber Wrap Installation
Case Study
Exterior Pipe Strengthening Application
Fiber Wrap Pipeline Applications
Hoop and Longitudinal Fiber Application
Fiber Wrap Pipeline Applications
Minimum ID for man-entry applications: 36”
16
End Termination
Detail
Special Details
Outlets Epoxy mortar
Case Study
Finish Coating Application
Case Study
Circulating Cooling Water System
QA/QC Process
• 3rd party inspector used for projects, to perform full time inspection
throughout CFRP installation
• Selected QA/QC steps documented
• Verify installation is in accordance with drawings and
specifications
• Condition of host pipe
• Control of air flow, temperature, and humidity
• Surface preparation
• Adhesion tests
• Material saturation
• Application (details, timing)
• Termination details
• Preparation of witness panels
• Post-installation inspection
• Curing (85% cure before service)
• Thickness measuring device
In-Situ Quality Control Testing: ASTM D4541
Adhesion Testing
20
Quality Control Testing: ASTM D3039
Validate Tensile Properties
• No blisters or delaminations
• No cracking, softening, or edge lifting
• In same condition as installed
Inspection of Tyfo® Fibrwrap® Installation
After 8 Years of Service
ASME B31.1 Design Considerations
• B31.1 Provides Limited Guidance on Non-Metallics
• Capacities not provided for CFRP
• Assumes an isotropic Material
• B31.1 Provides Limited Guidance on Buried Pipe
• Nothing on Surcharge Loads
• Nothing on Soil Loads
• Some Analysis Guidance on Loads in Appendix VII
• ASME now has Standards Committee on Non-metallic Pipe
• Non-metallic Pressure Piping Systems
• Just Beginning to Develop Standards
• May Address CFRP in the future
ASME B31.1 Design Considerations
• Unique Design criteria development required
• Must be B31 Compliant
• Used the following:
• B31.1
• AWWA M11, M45, C150
• ALA “Guidelines for Design of Buried Steel
Pipe”
• ASME BPVC Code Case N755-2
ASME B31.1 Design Considerations
Design Loads to Consider
• Pressure boundary design
• Deadweight and fluid weight
• Thermal expansion and contraction
• Non-repeated anchor motions
• Soil and surcharge loads
• Ring Deflection
• Through wall bending
• Strain based
• Extrapolate test data
• Side wall compression
• Ring buckling
• Negative internal pressure
• Floatation
ASME B31.1 Design Considerations
Surcharge Load to Consider
• Soil Loads
• Dry
• Saturated
• AASHTO HS20 Truck Loads
• Cooper E80 Rail Car Loads
• Water Table Loads
ASME B31.1 Design Considerations
Issues to Consider
• Uni-axial Material
• Credit only fibers in direction of loading
• Material should be wrapped in both the
circumferential and axial direction
• Circumferential fibers design for Circumferential
loads
• Axial fibers designed for axial loads
• Establishment of Basic Allowable stress
• Brittle material
• Suggested to use S = Su/10 per B31.1
ASME B31.1 Design Considerations Issues to Consider (cont)
• Establishment of secondary stress limits
• B31.1 uses SA = f(1.25 Sc + .25 Sh)
• Based on MARKL fatigue test in the 1940’s
• No such data for CFRP
• Use the S primary Stress limit
• Use of primary stress limits for secondary and fatigue
stress is judged conservative
• Stress Intensification Factors
• Not available for CFRP
• Assumed to geometrically dependent
• S&A conducted extensive SIF development for HDPE
• Compare HDPE SIF to B31.1
• Reasonable match – B31.1 SIF judged adequate
ASME B31.1 Design Considerations Issues to Consider (cont)
• Area Replacement
• Additional reinforcement at openings needed
• Apply the B31.1 area replacement rules
• No B16 series standard fittings
• Therefore, reinforcement should be considered
for all openings
• Uniaxial material behavior must considered
Code and Standard Activity
CFRP Task Group – Section XI
• Commercial US Pressure Codes now looking at non-metallics
• ASME now has Standards Committee on Non-metallic Pipe
• “Non-metallic Pressure Piping Systems”
• Just beginning to develop Standards
• Focus is plastics – HDPE, PVC, etc.
• May Address CFRP in the future
• ASME BPVC Activity
• Section III – Nuclear Plant Design
• HDPE is acceptable for Safety Class 3 systems
• Code Case N-755, Rev 2
• Is being converted to a Mandatory Appendix
• Section XI – Nuclear Plant Operation
• HDPE is acceptable for repair and replacement
• CFRP repair Code Case in development
Thank you!
Scott. F. Arnold, P.E.
Fyfe Company
Director of Engineering
Cell. 858-337-8935
Neda Stoeva for Timothy M. Adams
JD Stevenson and Associates, Inc.
Chief Mechanical Engineer
Off. 216-446-0520 X151