Excess Flow Valves

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Excess Flow Valves Implementation Challenges

• Bill Norton
• PIPES Act of 2006
• EFVs
• Anthony Cadorin
• City Of Mesa Sizing Procedures
• EFV Sizing

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Excess Flow Valves
Bill Norton
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Prior Legislation

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

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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

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New Legislation
Further Considerations

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

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The Big Day

• June 1, 2008
• PIPES Act of 2006

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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

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How EFVs Function
Closed Gas Flow Is Blocked
Open Gas Flows Unobstructed
Activation is DIRECTLY dependent upon Gas Velocity
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Types of EFVs

• Positive Shutoff (EFVNB)
• 100 shut off
• Manually reset
• Bleed-by (EFVB)
• Approximately 97 shut off
• Self-resetting
• lt20 standard cubic feet of gas per hour (Scfh) _at_
  10 psig

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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

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Applications
Mechanical Coupling Mechanical Tapping Tee PE
Stick Fusion Tapping Tee Shut Off Valve
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Who is using EFVs?

• Ohio 450,000
• Pennsylvania 200,000
• Massachusetts 176,000
• Minnesota 113,000
• Mostly Northeastern states
• Voluntary not state or federally mandated

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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

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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

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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

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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

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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

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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

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Surveyed Issues

• False Trips
• Line contaminants
• Improper Installation
• Third Party Damages

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Further Consideration

• Not installed on
• Multi-family homes
• Branch services
• Multi-metered manifolds

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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

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EFV SizingAnthony Cadorin
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City of Mesa sizing table
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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

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Creating a sizing table for Gas City
Not an option
Not an option
?
Not an option
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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 manufacturers flow rates for trip
  points

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Creating a sizing table for Gas City
Minimum system pressure 10 psig
EFV Inc. 400 Series EFV
This EFV will work
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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 _at_ 10
  psig 615 Scfh
• Pressure drop across EFV 0.66 psig per
  manufacturer (include in ?P calculation
• Use the IGT improved flow equation and solve
  for length L

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Creating a sizing table for Gas City
Not an option
Not an option
Not an option
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Creating a sizing table for Gas City
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Typical Appliance Loads
224 Scfh 250 Class Meter
624 Scfh! New meter required!
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Questions?