Multi-family New Construction 2 PSIG Program
- New multifamily construction only (apartment - townhouse - condominium)
- Individual metering for each dwelling unit
- Approved request from SoCalGas® before specifying any 2 PSIG system
- Approval of municipal building inspector
- Acknowledgment and agreement with house line step-down regulator location requirement
How to Participate
- Review Participation Requirements
- Download and Submit Your Application
- Secure approval of SoCalGas and the municipal inspector
- Review Installation Requirements with SoCalGas and your plumbing contractor
Fundamentals of 2 PSIG Distribution
How it Works
In many cases, this run of pipe can be 100 to 200 feet long. The use of 2PSI pressure will typically result in 1/2- or 3/4-inch pipe for this run compared to the 1or 1-1/4-inch pipe commonly used in low pressure systems. Once inside the dwelling unit, a line regulator reduces the natural gas pressure to the traditional 8-inch WC. The line regulator is necessary because residential appliances are designed to burn natural gas only at low pressure.
Configuration of interior natural gas piping
There are many ways to configure the interior natural gas piping network, depending on the layout of the building and dwelling unit, the number of appliances per dwelling unit, and the location of the natural gas meters. The 2PSI program is based on SoCalGas program requirements. Each multifamily building is somewhat unique when it comes to designing the meter bank needed to provide each unit with its own natural gas meter.
The location of the building relative to the natural gas main in the street and the property line will influence the design of the meter bank. The location and design of the meter bank, in turn, will affect the design of the natural gas piping system inside the building. The following examples are but a few of the different possibilities. The piping system can incorporate any approved piping material and/or combination of materials.
Low-rise installation with header and branch lines
Low-rise installation with parallel branch lines
Basic Pipe Sizing
The 2 PSIG Section
- Calculate the natural gas load (by adding up the name plate ratings) from all connected appliances.
- Measure length of pipe from the meter to the line pressure regulator located inside the dwelling unit.
- If there are multiple line pressure regulators, then measure the distance from the meter to the regulator furthest removed from the meter.
- The maximum allowable pressure drop for the 2PSI section is 1PSI.
- Referring to Table A for 2PSI systems with a 1PSI pressure drop, find this distance in the top row, or the next larger distance if the exact distance is not listed.
- Trace down this column until the natural gas load is found or the next larger capacity if the exact value is not listed.
- Read across the table back to the left hand column and select the appropriate pipe size.
- If there are multiple regulators in the system, each line segment must be sized for its actual natural gas load but using the longest length previously determined above.
Parallel branch line arrangement (2 PSI section)
Header and branch line arrangement (2 PSI section)
The Low-pressure Section
All piping downstream of the line-pressure regulator
- Measure the distance from the line regulator to the appliance furthest removed from the regulator.
- Use this distance to size all of the low-pressure appliance runs.
- Referring to Table B for 8-inch. WC systems with 1/2 in. WC pressure drop, find this distance in the top row or the next larger distance if the exact distance is not listed.
- Trace down this column until either the appliance natural gas load or the load for that section of pipe is found; find the next larger capacity if the exact value is not listed.
- Read across the table to the left hand column and select the appropriate pipe size.
- Repeat this process for each connected appliance or piping section.
Parallel branch line arrangement (low-pressure section)
Header and branch line arrangement (low-pressure section)
For More Information Contact New Construction
Table A. Pipe-sizing Data
Maximum deliver capacity of pipes of different diameters and lengths in cubic feet of natural gas per hour for an initial pressure of 2.0 PSI and a natural gas of .06 specific gravity.
Table B. Pipe-sizing Data
Maximum deliver capacity of pipes of different diameters and lengths in cubic feet of natural gas per hour for an initial pressure of 7-inch water column with a 0.5-inch water column pressure drop and a natural gas of 0.6 specific gravity