Robert Gleim Oct. 27 th, 2010

 Pipe is designed to handle the following load conditions: ◦ A minimum design life of 20 years at MAOP and MAOT ◦ Hydro testing to 1.25x MAOP for 8 hours at MAOT  The Hydro test can be performed up to 3 times during the life of the pipe without degrading the 20 year design life  Pipe shall have a minimum design life of 1 week when continuously operated at 1.25x MAOP  The pipe design strength is based only on the aramid fiber. ◦ No strength is attributed to the plastic.

 Base Tube ◦ Plastic is a seal and permeation barrier layer only  No strength is attributed to the plastic. ◦ Multi-Layer or Single Layer  Tri-axial aramid fiber ◦ Provides the strength to maintain both axial and radial loads ◦ Maximum efficiency of braid  Jacket ◦ Used to protect the aramid fiber from damage during handling and installation  No strength is attributed to the plastic.  Couplings ◦ Provide connections between pipe lengths and retains aramid fiber to prevent slippage.

 Fluid Compatibility ◦ HDPE  Water only ◦ Nylon  Water with Hydrocarbons & CO2 ◦ PPS  Water with Hydrocarbons, CO2, & H2S  Liner Material: ◦ Nylon Inert to Hydrocarbons  Doesn’t Soften and Swell  Doesn’t Lose Strength  Inert to Wet CO2  Not for H2S over 200PPM ◦ PPS  High H2S environments  Jacket Material ◦ Nylon for pipe pulls  Good abrasion resistance ◦ Polypropylene or nylon for direct bury Plastic Selection

 Tri-axial fiber reinforcement ◦ Axial fibers sized to carry 100% of axial load and to maintain elongation at less then 1%. ◦ Radial fibers sized to carry 100% of radial load  Braid angle optimized to minimize braid consumption and maximize production lengths Neutral Braid Angle = 54.7°

Why Aramid Fiber?  Graphite/Carbon fiber ◦ High strength & good resistance to cyclic loading ◦ Too expensive  Aramid fiber ◦ Very similar properties to carbon fiber ◦ Good balance of cost and performance  S- Glass fiber ◦ Low cost, high initial strength ◦ Reduced strength in moist environments due to crack growth ◦ Poor cyclic performance

 It is necessary to understand the long term behavior of aramids under load. ◦ Strength of the fiber is influenced by load, time and temperature ◦ Product life increases with decreased temperature and load

 It is necessary to understand the long term behavior of aramids under load. ◦ Aramid fiber will retain its full strength for more than 80% of its predicted time to failure. ◦ Time to failure is determined by Miners Rule:

 See attached chart for example below.  At 90°F, the pipe must meet the criteria of 20 year design life and Hydro testing at 1.25x MAOP. ◦ At MAOP, the load in the fiber is only 53.2 % of the short term breaking strength (B.S.). This yields a design life maximum of 50 years. ◦ A 1.25x MAOP hydro test, increases the aramid fiber load to 66.5% of B.S. with a max design life of 1 week.  If three - 8 hour, 1.25x hydro tests are performed on the pipe during its life, approximately 14.2% of the pipe life is consumed during the 24 hours of testing (24 out of 168 hr design life)  The remaining pipe design life is approximately 34 years ◦ (85.8% of 50 years x 80% of predicted life at full strength)

66.5% Approximately a 50 Year Design Life

A Factor of Safety (FS) is the structural capacity beyond the anticipated applied load. A FS is used to provide a design margin over the theoretical design capacity to allow for uncertainty in the design process. The uncertainty could be any one of a number of the components of the design process including calculations, material strengths, manufacture quality, environmental conditions, duty, etc.  Accounting for Uncertainties: ◦ Design uncertainties:  2D vs 3D effects & braid efficiencies accounted for by burst testing samples at operating temperature, thus FS=1 ◦ Manufacturing uncertainties:  Braid pitch, angle, diameter and wall thickness variations accounted for by burst testing samples at operating temperature, thus FS=1 ◦ Material uncertainties:  Braid: varies for temp and design life, typically between FS=2.03 to FS =2.81 ◦ Operating uncertainties:  Variability in installation, bend radii, operating pressure & temp, thus FS=1.1 Minimum Factor of Safety for Gathering lines is greater than 2.2