A. Service weight cast iron pipe is the standard cast iron pipe with bell and spigot connections. It is used for
gravity flow sanitary drain, waste, vent, sewer and storm drains in non-pressure installations. Service weight cast iron pipe and fittings must conform to ASTM specifications as set forth in ASTM A 74 that specifies the physical composition, dimension requirements, the quality of the finished product and testing requirements to ensure the piping conforms to this standard. Service weight is the minimum grade of cast iron piping that can be used in residential or commercial plumbing bell and spigot applications. An Extra Heavy Duty Cast Iron pipe is also available but is very rarely used except for extreme soil conditions and in special industrial applications.