All cast in place conduit SCH 80 PVC?

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housemoney

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Division 26 specs for a water treatment plant call for all conduit embedded in concrete to be heavy wall PVC conduit. I’ve ran countless miles of cast in place conduit in similar facilities with engineering designs, and heavy wall certainly has its place, but literally everywhere in the slab (all signal, control and power conduit of every size in concrete) in a massive facility within 12” concrete slabs between 2 rebar mats??? Non seismic area, no truck traffic etc. My RFI came back stating “it’s common place, no substitutions”.

Doesn’t this seem like an unnecessary cost? Has anyone seen where schedule 40 PVC conduit wouldn’t be allowed for no apparent reason?
 
Specs can be anything the designer wants until the owner / customer asks for VE on the project. A company I worked for did a water treatment plant where RMC was specked for the underground and slabs.

Roger
 
There was another post on here recently that the OP was having the same issue with an engineer., although I thik that was underground not concrete encased
 
roger said:
Specs can be anything the designer wants until the owner / customer asks for VE on the project. A company I worked for did a water treatment plant where RMC was specked for the underground and slabs.

Roger
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well, it was already added to the list of VE items to propose, as I’d also read: “the contractor may be requested to propose VE solutions”.

Isn’t the first time and won’t be the last EE specs have left me scratching my head.
 
The spec calls for "Heavy Wall PVC" and not SCH 80 specifically? There is a lot of conduit literature that calls SCH 40 heavy wall PVC. If you want to push it, I would submit a SCH 40 conduit that the spec sheet calls it heavy wall.
 
Yes sch 40 could be called heavy wall as there is a sch 20 conduit available. Often the EE specs are copied and seldom changed. I saw specs many years ago that called for Westinghouse Lamps, and they have not made lamps for some time before then
 
housemoney said:
Division 26 specs for a water treatment plant call for all conduit embedded in concrete to be heavy wall PVC conduit. I’ve ran countless miles of cast in place conduit in similar facilities with engineering designs, and heavy wall certainly has its place, but literally everywhere in the slab (all signal, control and power conduit of every size in concrete) in a massive facility within 12” concrete slabs between 2 rebar mats??? Non seismic area, no truck traffic etc. My RFI came back stating “it’s common place, no substitutions”.

Doesn’t this seem like an unnecessary cost? Has anyone seen where schedule 40 PVC conduit wouldn’t be allowed for no apparent reason?
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Schedule 80 PVC i believe is a substitute of Rigid or IMC but schedule 40 PVC is not, that might even be in the NEC somewhere.

It’s common place in 'municipal work' engineering to require rigid conduit, schedule 40 PVC is fine for commercial and residential.
If your doing bridge work, water treatment, airports, hospitals, military, critical operations stuff the standard is RIGID, IMC or schedule 80.

There are many interesting reasons people give, but its been standard as long as I have been doing this.
Interestingly on the utility side you can put some really flimsy conduit in a duct bank its like schedule 20.
They don't even call it conduit they call it 'duct'.
 
tortuga said:
Schedule 80 PVC i believe is a substitute of Rigid or IMC but schedule 40 PVC is not, that might even be in the NEC somewhere.
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Schedule 80 is identified for use in areas of physical damage, see the UL white book and the I.N. after 352.10(F)

Roger
 
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