Gas line diagram & sizing

Note: Contractor - installer responsible for correct gas line sizing

Main gas line diagram showing the generator connected to the gas meter via a gas line featuring a shut-off valve and flux link. Minimum clearance dimensions of 18 inches and 3 feet from walls or obstructions are noted.
Gas line layout and clearance diagram
Seismic anchoring detail drawing showing the generator frame secured to a concrete base using expansion anchor bolts, nuts, and washers with a minimum embedment depth of 2.5 inches.
Seismic anchoring detail

Site selection and preparation

Requirements for generator placement and site clearance.
Tag ID Description Comments
A Top of generator None
B Front and end clearance Minimum clearance distances cannot include shrubs, bushes, or trees.
C Rear clearance 18 in (45.7cm) minimum clearance per NFPA testing, labeling, and listing, unless state or local codes dictate otherwise.
D Windows and openings No operable windows, doors, or openings in the wall are permitted within 5 ft (1.52 m) from any point of the generator.
E Existing wall One-hour fire rated walls allow closer placement of the generator set. Confirm before installation.
F Removable fence Removable fence panels for servicing cannot be placed less than 3 ft (0.91m) in front of the generator.
G Overhead clearance 5 ft (1.52 m) minimum distance from any structure, overhang, or projections from the wall. Do not install under wooden decks or structures unless this distance is maintained.

Natural gas pipe sizing

Allowable pipe distance in feet/meters for natural gas.
Generator size 0.75/19 (in/mm) @ 5-7 in WC 1/25 (in/mm) @ 5-7 in WC 1.25/32 (in/mm) @ 5-7 in WC 1.5/38 (in/mm) @ 5-7 in WC 2/51 (in/mm) @ 5-7 in WC 1/25 (in/mm) @ 3.5-5 in WC 1.25/32 (in/mm) @ 3.5-5 in WC 1.5/38 (in/mm) @ 3.5-5 in WC
9 kW 55/16.76 200/60.96 820/249.94 None None 20/6.1 60/18.9 175/53.34
11 kW None 85/6.1 370/112.78 800/243.84 None None 60/18.9 175/53.34
16-22 kW None 20/6.1 130/39.62 305/92.96 945/288.04 10/3.05 60/18.9 125/53.34

LP vapor pipe sizing

Allowable pipe distance in feet/meters for LP vapor at 10-12 in water column (19-22 mmHg).
Generator size 0.75/19 (in/mm) 1/25 (in/mm) 1.25/32 (in/mm)
9 kW 165/50.29 570/173.74 None
11 kW 70/21.33 255/77.72 1000/304.8
16 kW 25/7.62 130/39.62 540/164.59
20-22 kW 15/4.57 115/35.05 480/146.3

Customer information

  • NameJohn Doe
  • Address100 Main Street, San Rafael, CA 94901
  • APN000-000-00
  • AHJCA- City San Rafael
  • Document titleGas line diagram
  • Designer/Checked byNone
  • ScaleAs noted
  • DateNone
  • Sheet numberE-2