Trench Work

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Alwayslearningelec

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NJ
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Estimator
Question for those who've installed pvc duct banks. This is for 4"
1. Do you use pre fab or bend for elbows?
2. When/if you have pre fab elbow you need coupling to couple the stick to the elbow?
3. When transitioning to and RGS elbow you need male PVC adapter to thread onto RGS coupling?
 
horsegoer said:
Question for those who've installed pvc duct banks. This is for 4"
1. Do you use pre fab or bend for elbows?
2. When/if you have pre fab elbow you need coupling to couple the stick to the elbow?
3. When transitioning to and RGS elbow you need male PVC adapter to thread onto RGS coupling?
Click to expand...
1. Generally bend with torch 🤫.
2.No if you buy a 90 with a bell on one end.
3.Yes.
 
I've done a few duct banks from sub stations to utility service centers. Most of these were 5" PVC with a few manholes every 500'. We used chairs to rack them so we could get total concrete encasement and rigid 90°s and 45°s using PVC female adapters. If the bends were slight, we would use a heating blanket to bend the conduit. Don't forget your burial tape rules and use some red concrete!
 
Rick 0920 said:
I've done a few duct banks from sub stations to utility service centers. Most of these were 5" PVC with a few manholes every 500'. We used chairs to rack them so we could get total concrete encasement and rigid 90°s and 45°s using PVC female adapters. If the bends were slight, we would use a heating blanket to bend the conduit. Don't forget your burial tape rules and use some red concrete!
Click to expand...
Thanks. if you terminating the PVC on the RGS elbow end that doesn't have the coupling then you use a female adapter but if RGS elbow end with a coupling then a male adapter??

So even the "horizontal" bends within the trench you used RGS elbow? Not just when coming out of the ground?
 
horsegoer said:
Thanks. if you terminating the PVC on the RGS elbow end that doesn't have the coupling then you use a female adapter but if RGS elbow end with a coupling then a male adapter??

So even the "horizontal" bends within the trench you used RGS elbow? Not just when coming out of the ground?
Click to expand...
It was in the specs that bends over a certain degree (30 I think) required rigid. These jobs were usually commissioned. A separate company was hired to inspect after the local AHJ. Since the pulls were so long it was a good idea. A lot of weight with the 15kV medium voltage cable so the potential was there for the rope to burn through the PVC. We never banged the bell end onto the threaded end of rigid. I've heard of many people that do that but it just wasn't a practice on my jobs. We always used FA's
 
Rick 0920 said:
It was in the specs that bends over a certain degree (30 I think) required rigid. These jobs were usually commissioned. A separate company was hired to inspect after the local AHJ. Since the pulls were so long it was a good idea. A lot of weight with the 15kV medium voltage cable so the potential was there for the rope to burn through the PVC. We never banged the bell end onto the threaded end of rigid. I've heard of many people that do that but it just wasn't a practice on my jobs. We always used FA's
Click to expand...
Thanks. But you can't install a female adapter on the belled end can you?
 
Rick 0920 said:
No you can't. You would have to cut it off or turn the pipe around to save couplings. We ordered our conduit in 20' lengths.
Click to expand...
Thanks. So PVC comes with one end belled and another not.
Wouldn.t you always use the non belled end to go into the RGS elbow?
Also, why is using 20' lengths more beneficial than 10' lengths? Labor savings?
 
We would always use the non-belled end, use a strap wrench to tighten the FA on the rigid 90, then glue the FA to the conduit. The runs were so long so it was less labor intensive to use 20' lengths. PVC has one belled end and one is not.
 
Rick 0920 said:
We would always use the non-belled end, use a strap wrench to tighten the FA on the rigid 90, then glue the FA to the conduit. The runs were so long so it was less labor intensive to use 20' lengths. PVC has one belled end and one is not.
Click to expand...
Right and thanks. So if you used the non belled to go into the RGS elbow since one end of the RGS elbow has a coupling that end would need a male adapter. No?
 
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