Excess Flow Valve (EFV) Selection per 49 CFR 192.383
Selects the appropriate EFV for natural gas service lines based on federal regulations. Calculates maximum allowable flow, recommended valve size, trip flow rate, reset pressure, bypass flow, and compliance status. Required for new and replaced service lines serving single-family residences.
Service Line Properties
ft
Distance from main to meter set assembly
Operating Conditions
psig
Typical distribution: 0.25-60 psig
BTU/hr
Sum of all connected appliance ratings
°F
Ground temperature at service line depth
Gas Properties
-
Natural gas: 0.55-0.70
BTU/scf
Typical natural gas: 1000-1050 BTU/scf
📚 Learn the Theory
Understand EFV operating principles, 49 CFR 192.383 requirements, sizing methodology, and installation best practices