the advantages of using nonmetallic piping

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