Conduit-Compatibility Table

[edienberg]

Does some one have a recommendation as to what types of conduits, boxes, hardware, supports, etc to install in certain chemical rooms? Specifically Water and Wastewater treatment plants.

 

[Dennis Alwon]

Stainless steel???

 

[kwired]

PVC, fiberglass, stainless, are resistant to most corrosive environments, then there can be aluminum and brass but I think there is a little more for environments those won't stand up for in comparison. Also is PVC coated steel, which would be very corrosion resistant from the exterior but if you get corrosive agents inside could corrode from inside out on the steel portion.

 

[tom baker]

I have wired a lot of chlorination rooms for water treatment. Originally we used CL gas, and thankfully that is all gone, most have gone to 12.5% hypo, corrosive, but nothing like gas. We used PVC conduit, boxes, fiberglass strut, LTNM conduit and for single runs Arlington Clic Its. Sometimes we used SS strut, as the fiber glass is not good for unsupported spans. Use all SS hardware, 316 is better than 304.

We would typically run around the top of the room with 1" conduit, hit a 6x6x6 PVC box and drop down to equipment.
We did a small hypo building, about 20 x30 and ran 6x6 wireway all around the top and dropped down with PVC to equipment, outlets etc, I like wireway as in treatment plants, things are always being added.

For exposed runs, PVC is slow to install, has to be supported every 3 ft, and 1 ft from boxes, we would make a bending template out of plywood. Write your specs to limit factory 90s, best to heat and bend,

Your other option if PVC coated rigid, and that is challenging to work with. Consultants like it and if money is no issue can use it. PVC is fine if its in a location where it won't get hit or damaged, then can use Sch 80. PVC coated takes special threading dies and bending shoes, large contractors will have those

Waste water locations will be a lot more corrosive than water treatment, due to H2S gas and those locations could be PVC coated rigid, which can be Al or Steel. Stub ups should always be PVC coated rigid. Paper mills tend to use PVC coated aluminum.

We did a couple of water pump stations with cable tray. the state water health inspector had never seen cable tray, but again its very good for adding and changing.

Find a client who has done a recent job and get the specs. If its a government job, those are all in the public domain.

 

[edienberg]

Thanks for the input. My desire is to specify RAL with SS hardware and HDG supports everywhere except where we will have a chemical incompatibility. My end goal is to put together a matrix with chemicals down one side (y-axis) and Conduits/Hardware/Supports along the other (x-axis) and identify whether or not the chemical is compatible with the C/H/S combination.

 

[Shimp]

I have wired a lot of chlorination rooms for water treatment. Originally we used CL gas, and thankfully that is all gone, most have gone to 12.5% hypo, corrosive, but nothing like gas. We used PVC conduit, boxes, fiberglass strut, LTNM conduit and for single runs Arlington Clic Its. Sometimes we used SS strut, as the fiber glass is not good for unsupported spans. Use all SS hardware, 316 is better than 304.

We would typically run around the top of the room with 1" conduit, hit a 6x6x6 PVC box and drop down to equipment.
We did a small hypo building, about 20 x30 and ran 6x6 wireway all around the top and dropped down with PVC to equipment, outlets etc, I like wireway as in treatment plants, things are always being added.

For exposed runs, PVC is slow to install, has to be supported every 3 ft, and 1 ft from boxes, we would make a bending template out of plywood. Write your specs to limit factory 90s, best to heat and bend,

Your other option if PVC coated rigid, and that is challenging to work with. Consultants like it and if money is no issue can use it. PVC is fine if its in a location where it won't get hit or damaged, then can use Sch 80. PVC coated takes special threading dies and bending shoes, large contractors will have those

Waste water locations will be a lot more corrosive than water treatment, due to H2S gas and those locations could be PVC coated rigid, which can be Al or Steel. Stub ups should always be PVC coated rigid. Paper mills tend to use PVC coated aluminum.

We did a couple of water pump stations with cable tray. the state water health inspector had never seen cable tray, but again its very good for adding and changing.

Find a client who has done a recent job and get the specs. If its a government job, those are all in the public domain.

With PVC-coated steel or aluminum, is there a secret to removing the PVC coating on the cut ends prior to threading? The manual process on the mfgr sites is a pain, especially when you have a number of connections needed to be made.