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

scott@fyfeco.com

Cell. 858-337-8935

Neda Stoeva for Timothy M. Adams

JD Stevenson and Associates, Inc.

Chief Mechanical Engineer

tim@vecsa.com

Off. 216-446-0520 X151