PVC Conduit Question

[RDB85]

I’m looking to buy some PVC Conduit for some security lights rather than clip the cable. We don’t use it in work. But I know I need 20mm conduit but would I be okay using 20mm inspection elbows? I assume they just fit inside?

 

[Pete999]

I’m looking to buy some PVC Conduit for some security lights rather than clip the cable. We don’t use it in work. But I know I need 20mm conduit but would I be okay using 20mm inspection elbows? I assume they just fit inside?

No the tube fits inside the fittings and Don't forget to use the adhesive!!!!!

 

[RDB85]

No the tube fits inside the fittings and Don't forget to use the adhesive!!!!!

I’ve been given a length of 20mm PVC so I would need 25mm fittings.

 

[stitch]

No, you would use 20mm fittings such as these.

20mm Pvc Conduit & Fittings - White

 

[Mike Johnson]

Beat me to it, but only just.

 

[Pete999]

I’ve been given a length of 20mm PVC so I would need 25mm fittings.

No, 20mm fittings are designed, for 20mm conduit, you may need a bending spring as well as a tube cutter if you are doing a lot of tube work, although a Junior Hacksaw will do the job just as well, although a cutter makes a better job of cutting use Heavy duty tube it's easier to bend and work with. In my considerable experience. Light duty tube tends to kink when bending,

 

[RDB85]

No, you would use 20mm fittings such as these.

20mm Pvc Conduit & Fittings - White

Okay that’s what I’ve got. 20mm fixings, inspection bends and elbows. Looks like I will need some adhesive.

 

[westward10]

I would avoid manufactured bends and elbows they look terrible in any instance. Get a bending spring and use sets wherever possible and use BESA boxes as opposed to the fittings you suggest.

 

[Pete999]

Okay that’s what I’ve got. 20mm fixings, inspection bends and elbows. Looks like I will need some adhesive.

Yep and saddles, box lids and screws and if outside some waterproof gaskets,

 

[Mike Johnson]

The inspection bends do not allow a cable draw tape to push around the bend without taking off the face plate or perseverance, better to use a slow bend or as suggested above a bending spring to get a slow change of direction.

 

[Vortigern]

Yes and black conduit for outside. Plus if it's a long run, expansion coupler.

 

[westward10]

Steel saddles to comply with current standards.

 

[Pete999]

Yep and saddles, box lids and screws and if outside some waterproof gaskets,

What they said as well above, can't remember everything can I?

 

[Mike Johnson]

Twelve answers in 22mins is that a record?

 

[Pete999]

Twelve answers in 22mins is that a record?

Hope the poster is all clued up now good luck Matey.

 

[ipf]

Hope the poster is all clued up now good luck Matey.

With all this new info, so quickly, I wouldn't be surprised if he's GLUED up.

 

[Pete999]

With all this new info, so quickly, I wouldn't be surprised if he's GLUED up.

Hope he aint stuck up, hope it works out for him, despite the banter.

 

[MJPD29]

Okay that’s what I’ve got. 20mm fixings, inspection bends and elbows. Looks like I will need some adhesive.

Manufactured inspection elbows look terrible and amateur/DIY. Get a bending spring and make required bends. It's also cheaper in the long run.

 

[radiohead]

Yep and saddles, box lids and screws and if outside some waterproof gaskets,

Only thing I might add is that 'waterproof' gaskets don't waterproof. By all means fit them but when designing an external system always assume water will get in. Allow for drainage, by for example, fitting a terminal box at the lowest point with a small drainage hole. Do not enter lights and accessories from the top, come in from below or the side, and keep all joints out of conduit boxes.

 

[RDB85]

Manufactured inspection elbows look terrible and amateur/DIY. Get a bending spring and make required bends. It's also cheaper in the long run.

Never used a bending spring. I will order one and do all my straight cuts and see if I have any scrap left to practice with.

 

[Dustydazzler]

Never used a bending spring. I will order one and do all my straight cuts and see if I have any scrap left to practice with.

don’t forget to give the conduit a good hard rub before you try to bend it...

 

[telectrix]

what's wrong with inspection elbows? how else do you come through a wall and then 90 degrees (up/down/left/right)? do youm bent the tube and have it sticking 4" off the wall?

 

[westward10]

Back entry terminal box, manufactured bends look terrible.

 

[Pete999]

what's wrong with inspection elbows? how else do you come through a wall and then 90 degrees (up/down/left/right)? do youm bent the tube and have it sticking 4" off the wall?

Me, I use a back entry on an end box and shoot off from there, better than an Inspection elbow I reckon, but each to their own I guess.

 

[littlespark]

Careful with the springs. Get one from the same supplier as the pipe you are using. There can be discrepancies between the inside diameter of different manufacturers. so it it can either be too tight to push in, or too loose and cause wrinkles.

whoever said bending the pipe with a spring would be more economical.... it depends how good you are at bending.

I see nothing wrong with using manufactured bends for neatness. All uniform radii, all the same.

 

[Risteard]

I would avoid manufactured bends and elbows they look terrible in any instance.

Not to put too fine a point on it, but they are truly awful.

 

[RDB85]

I’ve ordered the pvc adhesive. The diameter is 20mm but the elbow and inspection bends and even the end boxes don’t fit inside the conduit. As I wanted to get it all measures and test fitted before using adhesive.

As the tubing doesn’t fit over them I assume you would make some cuts in the end to make the diameter smaller?

 

[ferg]

The tube fits inside the accessories???

 

[freddo]

???? The pipe goes INSIDE the port on the fittings, it should stay there on its own, no need to cut anything, it just pushes in.

 

[RDB85]

???? The pipe goes INSIDE the port on the fittings, it should stay there on its own, no need to cut anything, it just pushes in.

I know it should do this doesn’t it’s the same diameter. So it doesn’t push inside. Not sure if it’s the conduit or the fixings I’ve bought. The fixing are a brand make and the conduit was given to me.

I will get a photo to show you what I mean. I assumed that the fixings should fit inside, so I was a bit confused when they didn’t and thought do I need 25mm tubing.

 

[freddo]

Can you post a photo showing the issue? It's not something I've come across before!

 

[Risteard]

I know it should do this doesn’t it’s the same diameter. So it doesn’t push inside. Not sure if it’s the conduit or the fixings I’ve bought. The fixing are a brand make and the conduit was given to me.

I'm going to guess that you have 25mm conduit with 20mm accessories/fittings.

 

[RDB85]

Measures the conduit and the inspection bend both 2cm.

 

[littlespark]

Plumbing drain pipe comes in a 21mm diameter size. Could be you’ve been given drain pipe.

 

[freddo]

21.5mm overflow pipe?

Oops, crossed with LS.

 

[ipf]

Who 'gave' you the conduit/pipe?

 

[RDB85]

So looks like I need some 20mm pipe then. Thanks it was a mate, he’s not a plumber though it was a fellow spark lol

 

[Pete999]

No not if the conduit is 20mm, 20 mm everything Saddles, fittings and bending spring.

 

[telectrix]

Measures the conduit and the inspection bend both 2cm.

that'snot conduit. it's a wet-pants' water pipe.

 

[Mike Johnson]

Yes overflow pipe, but if you must use it, asa it is thick walled I have successfully turned it down at the end by putting a mandrel inside and turning it on an electric drill with some sandpaper or file, gets you out of a problem if needs be.

 

[telectrix]

Yes overflow pipe, but if you must use it, asa it is thick walled I have successfully turned it down at the end by putting a mandrel inside and turning it on an electric drill with some sandpaper or file, gets you out of a problem if needs be.

easier to get the right conduit. and why white? bloody eyrsore. black is more appropriate.

 

[RDB85]

easier to get the right conduit. and why white? bloody eyrsore. black is more appropriate.

Because I have white pvc windows and doors and a white iron gate. So black would stick out.

 

[Simon47]

Every brand of conduit I've used has had the make and size printed along it - typically about once a meter. I try and put the printing at the back where it's not visible when I fit it.
As to fitting vs forming ... Well that's a tricky one. I agree that well formed bends and sets look waaaay tidier than a load of bends and short bits of pipe. But on the other hand, making well formed bends and sets is an art form in itself and I would imagine a novice would need "a few attempts and some spare pipe" during the learning process (especially doing it free-form with a spring). I don't consider myself very good at it
As mentioned, give the pipe a good rub (to warm it) before bending, and bend it well past where you want it to stay as it will spring back considerably.

 

[Mike Johnson]

As much as the hate a plumber on here extends, they have their own problems in that each manufacturer of plumbing fittings make then all a slightly different size so not that easy to co-ordinate fittings to fit together, and then we have tried to fit plumbing pipe into conduit fittings, will this madness ever end. LOL

 

[davesparks]

Because I have white pvc windows and doors and a white iron gate. So black would stick out.

If it is being used externally it should be black.
[automerge]1586987575[/automerge]

Yes overflow pipe, but if you must use it, asa it is thick walled I have successfully turned it down at the end by putting a mandrel inside and turning it on an electric drill with some sandpaper or file, gets you out of a problem if needs be.

That won't make it compliant as an electrical conduit though, it is manufactured to a different BS and made from a different material.

 

[littlespark]

I did use plumbers pipe once myself. For running CCTV along the front of my own house. I’ve got a bay window, and the plumbers pipe come with 45’ bends.

 

[Zerax]

I did use plumbers pipe once myself. For running CCTV along the front of my own house. I’ve got a bay window, and the plumbers pipe come with 45’ bends.

Please please please can we see a pic of that...

 

[andyb]

Manufactured inspection elbows look terrible and amateur/DIY. Get a bending spring and make required bends. It's also cheaper in the long run.

And short runs

 

[freddo]

Overflow elbow used on white and black conduit...

the other end went to:

 

[Pete999]

Overflow elbow used on white and black conduit...
View attachment 57478
the other end went to:
View attachment 57477

Somewhat inventive to say the least, DIY job was it?