Upload
michael-yee
View
42
Download
0
Tags:
Embed Size (px)
Citation preview
Michael P. YeeRTConsults PLLC
April 17, 2014
The Advantages of Using Non-metallic Piping for Brine Service
• Localized Pitting and aggressive corrosion by SRB Bacteria
• Reduced service life and greater maintenance cost
• Operation downtime
The Issue: Corrosion
• Relatively lower cost than coated steel pipe
• Flexible and mildly chemical resistant
• Above and underground service friendly
• Rated up to 265 psi (varies on wall thickness)• 7-11 years life
High Density Poly Ethylene Pipe (HDPE)
High Pressure Alternative?
• Fiberglass Reinforced Plastic Pipe (FRP)
High Pressure Alternative
• Maintenance requirements/costs• Inspection costs, exterior
painting, interior relining, (Cathodic Protection not needed)
• FRP has a useful life of 20 years+ with proper resin selection, design, fabrication, and installation*
• Lightweight (4 times lighter than carbon steel)
• Consistent Flow-> (Hazen-Williams coefficient of 150, instead of ~80 for corroded).
Cost Savings with Non-Metallic
• Visual External• Visual Internal• Hardness Reader• Barcol Gauge• Gated Ultrasonic Meter
Inspection
• Design Pressure• Connections• Above Ground Installation• Underground Installation• Flow Considerations• Venting and Heat
Technical Considerations
• Safety factor of 10:1• Unlike carbon steel pipe which loses
thickness overtime, FRP does not.• FRP loses 20-50% over time due to stress
and prolonged use. • Long term safety factors of 5:1 in nearly
all cases.
• Ex. Operating cavern at 800psig= 1600psig rated working pipe (minimum).
Design Considerations
• Threads can be made to many different thread standards.
• Threaded pipe with fiberglass joint sealant is recommended.
• Too many flanges for high pressure operation is not recommended.
Connections
• Improper anchoring and supporting
• (no point loads)• Physical damage
(striking/improper installation).*
• Manufacture Instructions.
• Wrap rubber insulation around pipe through concrete/masonary holes.
Above Ground Installation
• Make sure all backfill material is free of stones ¾” in size.
Underground Installation
• Intense hammering or pressure surges• Unstable flow= angular twisting moment• Use vacuum breakers or slow valve
closings
Flow Consideration
• Each FRP system should be vented at the highest point.
• Wrap the whole pipe uniformly and avoid sides.
• Allow for thermal expansion (at elevated temperatures) if applicable
Venting and Heat
• Comprehensive and descriptive specifications
• Detailed system engineering• Qualify experienced GRP manufacturer• Quality control and supervision in
engineering, in the shop and in the field• Quality assurance throughout the process
Lessons Learned* Keys to a Successful Project
“You can expect what you inspect- nothing more.”
- John H. Mallinson
• Ashland Industries• Future Pipe Industries• Richard Taraborelli, PE
Credits