Properties of PVC Electrical Conduit vs PVC Pipe

[Bill Maher]

Can anyone tell me if there is a difference in the physical properties of NEMA TC-2 ( schedule 40) PVC electrical conduit and ASTM D2665 PVC Drain Waste and Vent piping (schedule 40)?

Thanks

[John Steinke]

As far as the standards are concerned, there is a difference. "Electrical" PVC supposedly has stiffeners (to give it strength ) and is sunlight resistant."Plumbing" PVC relies, in part, on the water inside for strength, and is not expected to be exposed to sunlight.

One manufacturer -Cantex- insists this is the case. One member of this board asserts that he's worked there, and it's all made of the same stuff. Believe whom you will.

[H.G. Watson, Sr.]

Difference to standards tested and rated/certified. Same PVC product may be have multiple ratings & markings i.e. PVC Sch. 40 & EPC 40.

Pressure testing & rating at standard temps (IIRC 23c) for the plumbing products, low tolerance lead/chemical leaching contaimination to potable standards (D1785 & D2265).

Putting off heat/heat buildup meeting insulation ratings (90c) for electrical tubing.

Some mfg's like crestline manufacture some PVC products that are dually tested and labeled/marked & NSF certified.

i.e. ASTM D1785/ASTM D2265/NEMA TC-2/UL 651

If the markings have been obscured or removed (paint thinner, painted, etc.) there is no way to tell visually. Same outer dia and wall thickness for same sizes.

[A.D. Miller]

PVC that is rated for electrical conduit is, for the most part, UV-resistant, where schedule 40 is not.

[Bill Maher]

Thanks to all for their input.

[Jim Port]

PVC that is rated for electrical conduit is, for the most part, UV-resistant, where schedule 40 is not.

Schedule is a measure of pipe wall thickness. PVC conduit, as well as water pipe can be in Schedule 40 and 80.

[Jerry Peck]

Schedule is a measure of pipe wall thickness. PVC conduit, as well as water pipe can be in Schedule 40 and 80.

Schedule is a relationship between wall thickness and diameter, not just wall thickness.

The intent is to provide a similar mechanical strength or pressure rating, and the larger the diameter the thicker the wall thickness needs to be to achieve the same strength/pressure rating.

[Jim Port]

True, I was just point out that Schedule 40 was improper terminology as far as this discussion in regards to conduit vs water pipe differences; ie just because it is labelled Sched 40 does not make it electrical conduit.