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Unit 2 Topic 3: Sizing of 2 psig Gas Piping Systems
(branch sizing method)
A 2 psig system has a service regulator and intermediate regulators
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Unit 2 Topic 3: Sizing of 2 psig Gas Piping Systems
(branch sizing method)
** Size each pressure zone separately **
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Unit 2 Topic 3: Sizing of 2 psig Gas Piping Systems
(branch sizing method)
First size the low-pressure zone, then the 2 psig zone.
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Unit 2 Topic 3: Sizing of 2 psig Gas Piping Systems
(branch sizing method)
Any low-pressure zones can be sized according to information in Topic 2.
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Unit 2 Topic 3: Sizing of 2 psig Gas Piping Systems
(branch sizing method)
The LMR for the low-pressure zone will be measured from the 2 psig regulator to the appliance.
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Unit 2 Topic 3: Sizing of 2 psig Gas Piping Systems
(branch sizing method)
To correctly identify the table for a 2 psig system requires the following information:
Type of gas: Natural gas or propane
Type of pipe: Iron pipe or copper tubing
System pressure: 2 psig
Pressure drop: 1 or 1.5 psig
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Unit 2 Topic 3: Sizing of 2 psig Gas Piping Systems
(branch sizing method)
Stepping through example 2-12:
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Unit 2 Topic 3: Sizing of 2 psig Gas Piping Systems
(branch sizing method)
Identify the low and high pressure zones:
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Unit 2 Topic 3: Sizing of 2 psig Gas Piping Systems
(branch sizing method)
Identify the low and high pressure zones:
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Unit 2 Topic 3: Sizing of 2 psig Gas Piping Systems
(branch sizing method)
Identify the low and high pressure zones:
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Unit 2 Topic 3: Sizing of 2 psig Gas Piping Systems
(branch sizing method)
What Table will be used for the low pressure zone?
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Unit 2 Topic 3: Sizing of 2 psig Gas Piping Systems
(branch sizing method)
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Unit 2 Topic 3: Sizing of 2 psig Gas Piping Systems
(branch sizing method)
What LMR and Code Zone will be used?
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Unit 2 Topic 3: Sizing of 2 psig Gas Piping Systems
(branch sizing method)
What LMR and Code Zone will be used?
LMR = 8 feet
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Unit 2 Topic 3: Sizing of 2 psig Gas Piping Systems
(branch sizing method) With an LMR of 8, Code Zone of
10 ft is used
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Unit 2 Topic 3: Sizing of 2 psig Gas Piping Systems
(branch sizing method)
What is the Pipe A load and required size?
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Unit 2 Topic 3: Sizing of 2 psig Gas Piping Systems
(branch sizing method)
What is the Pipe A load and required size?
Pipe A load = 120 MBH + 40 MBH
= 160 MBH
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Unit 2 Topic 3: Sizing of 2 psig Gas Piping Systems
(branch sizing method)
With a Load of 160 MBH, pipe A will
have to be
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Unit 2 Topic 3: Sizing of 2 psig Gas Piping Systems
(branch sizing method)
What Table will be used for the High Pressure Zone?
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Unit 2 Topic 3: Sizing of 2 psig Gas Piping Systems
(branch sizing method)
What Table will be used for the High Pressure Zone?
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Unit 2 Topic 3: Sizing of 2 psig Gas Piping Systems
(branch sizing method)
.
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Unit 2 Topic 3: Sizing of 2 psig Gas Piping Systems
(branch sizing method)
What Table will be used for the High Pressure Zone?
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Unit 2 Topic 3: Sizing of 2 psig Gas Piping Systems
(branch sizing method)
What is the LMR for pipes B & C?
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Unit 2 Topic 3: Sizing of 2 psig Gas Piping Systems
(branch sizing method)
What is the LMR for pipes B & C?
LMR = 44 feet
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For LMR of 44 feet, CZ of 50 feet is required
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Unit 2 Topic 3: Sizing of 2 psig Gas Piping Systems
(branch sizing method)
What is the Code Zone for pipe B/C?
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Unit 2 Topic 3: Sizing of 2 psig Gas Piping Systems
(branch sizing method)
What is Load for pipe B/ C?
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Unit 2 Topic 3: Sizing of 2 psig Gas Piping Systems
(branch sizing method)
What is Load for pipes B & C?
Load for Pipes B/C =
120 MBH + 40 MBH = 160 MBH
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For load of 160 MBH pipe size of NPS is
required