u.s. d.o.t. phmsa excess flow valves group meeting · u.s. d.o.t. phmsa excess flow valves group...

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U.S. D.O.T. PHMSA Excess Flow Valves Group Meeting Applications beyond single family residence

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Page 1: U.S. D.O.T. PHMSA Excess Flow Valves Group Meeting · U.S. D.O.T. PHMSA Excess Flow Valves Group Meeting ... •A device that takes advantage of Bernoulli’s ... •This principle

U.S. D.O.T. PHMSA

Excess Flow Valves

Group Meeting

Applications beyond single

family residence

Page 2: U.S. D.O.T. PHMSA Excess Flow Valves Group Meeting · U.S. D.O.T. PHMSA Excess Flow Valves Group Meeting ... •A device that takes advantage of Bernoulli’s ... •This principle

Brief Introduction

• R.W. Lyall remains dedicated to working with its customers to provide the products they need to provide safe and reliable service.

• R. W. Lyall first entered the EFV market in 1992 to meet a customers specific need.

• Today, R. W. Lyall supplies EFV’s to over 200 customers in the U.S.A., Canada & Mexico with an estimated 1MM units sold.

Page 3: U.S. D.O.T. PHMSA Excess Flow Valves Group Meeting · U.S. D.O.T. PHMSA Excess Flow Valves Group Meeting ... •A device that takes advantage of Bernoulli’s ... •This principle

Expanding EFV Application

• We need to be clear on what we are expanding.

• A device that is designed to reduce the flow of gas when conditions exceed predetermined levels.

• A device that takes advantage of Bernoulli’s principles to provide the force to close some sort of sealing mechanism that is normally held open by an opposing force(spring, magnet, gravity, etc.).

Page 4: U.S. D.O.T. PHMSA Excess Flow Valves Group Meeting · U.S. D.O.T. PHMSA Excess Flow Valves Group Meeting ... •A device that takes advantage of Bernoulli’s ... •This principle

An Illustration

• Actuation of a

Mechanical

Excess Flow

Valve is Directly

Dependent upon

Gas Velocity

through the

orifice causing a

pressure drop

across the valve.

Page 5: U.S. D.O.T. PHMSA Excess Flow Valves Group Meeting · U.S. D.O.T. PHMSA Excess Flow Valves Group Meeting ... •A device that takes advantage of Bernoulli’s ... •This principle

What’s Happening?

• The plunger

is exposed

to three

forces

Downstream

pressure

Upstream

pressure

Spring

Plunger

Page 6: U.S. D.O.T. PHMSA Excess Flow Valves Group Meeting · U.S. D.O.T. PHMSA Excess Flow Valves Group Meeting ... •A device that takes advantage of Bernoulli’s ... •This principle

How Do They Work?

• When the

pressure

drop across

the device is

just right…

Downstream

pressure

Upstream

pressure

Spring

Plunger

• Snap! – The

EFV closes.

Page 7: U.S. D.O.T. PHMSA Excess Flow Valves Group Meeting · U.S. D.O.T. PHMSA Excess Flow Valves Group Meeting ... •A device that takes advantage of Bernoulli’s ... •This principle

What does this mean?

• This device actuates when a specific

pressure differential signature is created.

• This principle of operation remains true as

the size of the device and “trip point” of

the device are increased.

Page 8: U.S. D.O.T. PHMSA Excess Flow Valves Group Meeting · U.S. D.O.T. PHMSA Excess Flow Valves Group Meeting ... •A device that takes advantage of Bernoulli’s ... •This principle

What does this mean?

• The device itself does not know what

EXCESS flow is.

• It is very reliable but “Dumb”.

P Valve EFV Valve

=When properly sized

and designed into

the service system

Page 9: U.S. D.O.T. PHMSA Excess Flow Valves Group Meeting · U.S. D.O.T. PHMSA Excess Flow Valves Group Meeting ... •A device that takes advantage of Bernoulli’s ... •This principle

How Do I Determine the Correct EFV

for My Application?

• ASTM F 2138 suggests that an EFV should be selected with a trip flow, at the distribution system minimum pressure, above the maximum customer load, and above meter capacity.

• For residential services the anticipated load is determined and the appropriate EFV is selected to prevent Nuisance Trips and provide protection for the entire service length.

• For Commercial and Industrial applications sizing needs to be even more carefully considered as load requirements can be more variable.

Page 10: U.S. D.O.T. PHMSA Excess Flow Valves Group Meeting · U.S. D.O.T. PHMSA Excess Flow Valves Group Meeting ... •A device that takes advantage of Bernoulli’s ... •This principle

Why is this important?COMMERCIAL EFV SIZING EXAMPLE

MIN TRIP

MAX TRIP

.92 Inch Hole

215241 Inch Hole

1.2 Inch

Hole

.75 Inch Hole

0

10000

20000

30000

40000

50000

60000

70000

80000

90000

100000

0 20 40 60 80 100 120 140

psig

SC

FH

2 IPS DR 11 Service Pipe (1.92" I.D.)

150 Ft Service Length

6 psig min. @ Regulator

EFV

Min. Trip 20000 SCFH

@ 10 psig

Future Load = 6 X 3000 SCFH

»180 thm

Initial Load = 6 X 800 SCFH

»48 thm

1st look EFV Min. Trip

5500 SCFH @ 10 psig

15,200

SCFH

Page 11: U.S. D.O.T. PHMSA Excess Flow Valves Group Meeting · U.S. D.O.T. PHMSA Excess Flow Valves Group Meeting ... •A device that takes advantage of Bernoulli’s ... •This principle

What does Damaged Pipe Look Like?

Page 12: U.S. D.O.T. PHMSA Excess Flow Valves Group Meeting · U.S. D.O.T. PHMSA Excess Flow Valves Group Meeting ... •A device that takes advantage of Bernoulli’s ... •This principle

Summary

• The devices are relatively simple and will reliably function under specific conditions.

• The principles of operation remain the same as sizes become larger and “Trip points” are increased.

• The device only becomes an EXCESS flow valve when it is properly sized within the service system.

• Not all situations will derive the same benefits from the installation of an EFV.

Page 13: U.S. D.O.T. PHMSA Excess Flow Valves Group Meeting · U.S. D.O.T. PHMSA Excess Flow Valves Group Meeting ... •A device that takes advantage of Bernoulli’s ... •This principle

Thank you!

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