Section 192.369 - Service lines: Connections to cast iron or ductile iron mains(a) Each service line connected to a cast iron or ductile iron main must be connected by a mechanical clamp, by drilling and tapping the main, or by another method meeting the requirements of §192.273.(b) If a threaded tap is being inserted, the requirements of §192.151 (b) and (c) must also be met.