Just to clarify - both sch 40 and sch 80 fittings have a standard ID which is the same for both and matches the OD of the pipe. Sch 40 and Sch 80 pipe can be used interchangably with sch 40 and sch 80 fittings. The extra thickness for the fittings makes the Outside Diameter larger. For pipe, sch 80 has a thicker wall but a standard OD; therefore, the ID of a sch 80 pipe is smaller than the ID of a sch 40 pipe. That's what I meant to say initially.
Sch 40 PVC and CPVC - 1" Pipe - OD 1.315" - ID 1.049" - Min Wall 0.133"
Sch 80 PVC and CPVC - 1" Pipe - OD 1.315" - ID 0.957" - Min Wall 0.179"
So, what does PVC stand for? - I didn't know, so I looked it up.
PVC - Polyvinyl Chloride
- strong and rigid
- resistant to a variety of acids and bases
- may be damaged by some solvents and chlorinated hydrocarbons
- maximum usable temperature 140oF (60oC)
- usable for water, gas and drainage systems
- not useable in hot water systems
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