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Excess Flow Valves – Implementation Challenges

Excess Flow Valves – Implementation Challenges. Bill Norton PIPES Act of 2006 EFVs Anthony Cadorin City Of Mesa Sizing Procedures EFV Sizing. Excess Flow Valves. Bill Norton. Prior Legislation. RSPA Final Rule, February 3 rd 1998, Effective February 3 rd 1999

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Excess Flow Valves – Implementation Challenges

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  1. Excess Flow Valves – Implementation Challenges Bill Norton • PIPES Act of 2006 • EFVs Anthony Cadorin • City Of Mesa Sizing Procedures • EFV Sizing

  2. Excess Flow Valves Bill Norton

  3. Prior Legislation • RSPA Final Rule, February 3rd 1998, Effective February 3rd 1999 • Required either notification of availability or installation

  4. New Legislation Installation on single family residential service if: • Installed or replaced after June 1, 2008 • Operates continuously throughout the year at a pressure not less than 10 psig • Is not connected to a main with prior experience with contaminants • Non-interference with necessary operation or maintenance activities • Commercially available

  5. New Legislation Further Considerations • Annually reportable • Reportable procedure has not been determined • Reference to Sec.9.(3)(A-B), and (6)

  6. “The Big Day” June 1, 2008 PIPES Act of 2006

  7. What is an EFV? • Self-actuating valve • In-line mechanical device • Responds to the high-pressure differential • Designed to activate when a rupture occurs • Stop or minimize the flow of gas

  8. How EFVs Function Closed: Gas Flow Is Blocked Open: Gas Flows “Unobstructed” Activation is DIRECTLY dependent upon Gas Velocity

  9. Types of EFVs • Positive Shutoff (EFVNB) • 100% shut off • Manually reset • Bleed-by (EFVB) • Approximately 97% shut off • Self-resetting • <20 standard cubic feet of gas per hour (Scfh) @ 10 psig

  10. Sizes • Typical Sizes - 400 Series - 1000-1200 Series - 800 Series - 1800 Series • EFVs are designated using their size • I.e. 400 series • At 10 psig, 400 standard cubic feet of gas per hour (Scfh) will cause the excess flow valve to trip

  11. Applications Mechanical Coupling Mechanical Tapping Tee PE Stick Fusion Tapping Tee Shut Off Valve

  12. Who is using EFV’s? • Ohio ~450,000 • Pennsylvania ~200,000 • Massachusetts ~176,000 • Minnesota ~113,000 • Mostly Northeastern states • Voluntary; not state or federally mandated

  13. Questionnaire • Conducted to determine industry standards • 14 operators surveyed across U.S. • Pacific Gas & Electric • NW Natural Gas • Citizens Gas & Coke • New Jersey Natural Gas • St. Lawrence Gas

  14. Industry Preference • PE “sticks” or In-line: 86% • Ease of replacement • In-line and Tapping Tees: 7% • Tapping Tee: 7% • Positive Shutoff: 29% • Bleed-by: 71%

  15. Common Basic Practices • Not installed where line pressure is 10 psig or lower • Unrealized trip flow rate • Pressure drop may affect flow rate • Design pressure minimum

  16. Common Basic Practices • Not installed where a high amount of contaminants are in the line (water, dust, grease, etc.) • Spring failure • False trips • Valve malfunction

  17. Common Basic Practices • Not installed on commercial applications • Transient nature of businesses • Additional load w/o notification • Breadth of capacity • Size of service line requirements

  18. Common Basic Practices • Not installed in emergency situations Not enough time to properly size the EFV which could potentially result in tripping the EFV during normal operational use

  19. Surveyed Issues • False Trips • Line contaminants • Improper Installation • Third Party Damages

  20. Further Consideration Not installed on: • Multi-family homes • Branch services • Multi-metered manifolds

  21. Challenges for Mesa • O & M; Construction Practices & Emergency Plan modifications • Pressure testing and purging procedures • EFV Sizing and installation • Bleed-by feature • Service annotation: Drawings and field • Training • Implementation

  22. EFV SizingAnthony Cadorin

  23. 250 Class Service Meters 400 Class Service Meters 800 Class and 1000 Class Service Meters 1/2” CTS 600 Series 75 feet max. length 800 Series 45 feet max. length Not an option 1/2” IPS 800 Series 300 feet max. length 800 Series 300 feet max. length 1800 Series 70 feet max. length 1” IPS 1800 Series 750 feet max. length 1800 Series 750 feet max. length 1800 Series 750 feet max. length City of Mesa sizing table

  24. Why a sizing table? • Meter size provides an upper limit on the amount of gas that a line will flow • Line size (diameter) sets up the maximum length that a given EFV will protect

  25. 250 Class Service Meters 400 Class Service Meters 800 Class and 1000 Class Service Meters 1/2” CTS 3/4” IPS 1” IPS Creating a sizing table for Gas City Δ Not an option Not an option Not an option

  26. Creating a sizing table for Gas City • EFVs must be sized at the lowest predicted operating pressure • Gas City: 10 psig • Maximum load is determined by the meter • 400 Scfh per meter manufacturer • Go to EFV manufacturer’s flow rates for trip points

  27. Creating a sizing table for Gas City Minimum system pressure: 10 psig EFV Inc. 400 Series EFV This EFV will work

  28. Creating a sizing table for Gas City Maximum service length protected: • Gas City lowest predicted operating pressure: 10 psig • EFV Inc. 400 Series EFV maximum trip point @ 10 psig: 615 Scfh • Pressure drop across EFV: 0.66 psig per manufacturer (include in ΔP calculation • Use the “IGT improved” flow equation and solve for length “L”:

  29. 250 Class Service Meters 400 Class Service Meters 800 Class and 1000 Class Service Meters 1/2” CTS EFV Inc. 400 Series 300 feet max. length 3/4” IPS 1” IPS Creating a sizing table for Gas City Not an option Not an option Not an option

  30. EFV ½” CTS 400 Series 300 ft. Maximum Length ¾” IPS 800 Series 300 ft Maximum Length 1” IPS 1800 Series 750 feet max. length Creating a sizing table for Gas City

  31. Typical Appliance Loads 224 Scfh: 250 Class Meter 624 Scfh! New meter required!

  32. Questions?

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