49 CFR § 192.365 - Service lines: Location of valves.
(a) Relation to regulator or meter. Each service-line valve must be installed upstream of the regulator or, if there is no regulator, upstream of the meter.
(b) Outside valves. Each service line must have a shut-off valve in a readily accessible location that, if feasible, is outside of the building.
(c) Underground valves. Each underground service-line valve must be located in a covered durable curb box or standpipe that allows ready operation of the valve and is supported independently of the service lines.
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