Transcript Excess Flow Valves: EFV 101

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 3rd 1998,
Effective February 3rd 1999

Required either notification of availability
or installation
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

New Legislation
Further Considerations
Annually reportable
 Reportable procedure has not been
determined


Reference to Sec.9.(3)(A-B), and (6)
“The Big Day”
June 1, 2008
PIPES Act of 2006
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

How EFVs Function
Open: Gas Flows
“Unobstructed”
Closed: Gas Flow
Is Blocked
Activation is DIRECTLY dependent upon Gas
Velocity
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

Sizes


Typical Sizes
- 400 Series
- 800 Series
- 1000-1200 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
Applications
Mechanical Coupling
Mechanical Tapping Tee
PE Stick
Fusion Tapping Tee
Shut Off Valve
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
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
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%

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
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
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
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
Surveyed Issues

False Trips

Line contaminants

Improper Installation

Third Party Damages
Further Consideration
Not installed on:

Multi-family homes

Branch services

Multi-metered manifolds
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

EFV Sizing
Anthony Cadorin
City of Mesa sizing table
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
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
Creating a sizing table for Gas
City
1/2”
CTS
250 Class
Service Meters
400 Class
Service Meters
800 Class and
1000 Class
Service Meters
Δ
Not an
option
Not an
option
3/4”
IPS
1”
IPS
Not an
option
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
Creating a sizing table for Gas
City
Minimum system pressure: 10 psig
EFV Inc. 400 Series EFV
Pressure Minimum Trip Point Maximum Trip Point
5
360
540
10
410
615
15
450
675
20
495
750
25
530
795
30
560
840
This EFV will work
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”:
Tb 1  P 
Q  664.3
.1111 
.8

Pb 
G
T
LZ
f


0.556
D 2.667 E
Creating a sizing table for Gas
City
250 Class
Service Meters
1/2”
CTS
EFV Inc. 400
Series
300 feet max.
length
3/4”
IPS
1”
IPS
Not an
option
400 Class
Service Meters
Not an
option
800 Class and
1000 Class
Service Meters
Not an
option
Creating a sizing table for Gas
City
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
Typical Appliance Loads
Barbecue
Clothes Dryer
Fireplace Log Lighter
Furnace
Cooking
Water Heater
Pool Heater
Spa
1000 sq. ft.
1500 sq. ft.
2000 sq. ft.
2500 sq. ft.
S/C Top Burner
S/C Oven Burner
C/C Top Burner
C/C Oven Burner
20 gal
30 gal
40 gal
50 gal
75 gal
100 gal
18-20k gal
> 20k gal
300-400 gal
> 400 gal
50 SCFH
22 SCFH
25 SCFH
80 SCFH
94 SCFH
109 SCFH
137 SCFH
10 SCFH
16 SCFH
9 SCFH
18 SCFH
28 SCFH
32 SCFH
41 SCFH
44 SCFH
59 SCFH
75 SCFH
300 SCFH
400 SCFH
175 SCFH
275 SCFH
224 Scfh: 250 Class Meter
624 Scfh! New meter required!
Questions?