Cable trays: Return Flange cable tray

[hisham.i]

I am designing cable tray for installation, while i am looking on different types of cables trays i found that there is cable trays called "Cable trays with return flange".

So i am wondering where such type of trays is used?

Thanks,
Hisham

 

[the_emi_guy]

Most cable trays have return flange because this makes them several times stronger. The actual strength is a function of the cross sectional detail (which includes the flange design) and material properties. You would probably only use non-return flange in cases where loading was minimal and you wanted to save a little money.

This is really a ME question and, unless this is something really simple, you need to work with your cable tray supplier because there are potentially lots of factors you need to consider:

Maximum span length between supports, maximum permissible deflection, material, surface treatment, loading (cable, wind, snow ...).

 

[AlephZero]

A return flange means the top edge of the flange is bent through 180 degrees, to make the flange double the thickness.

As #2 said, it makes the flange stronger. Also there are no sharp edges at the top of the flange, that might damage cables if they are pulled over the flange.

 

[hisham.i]

Thanks for your helpful info.

But i don't understand how can a flange on the top of the cable tray make it stronger?

 

[the_emi_guy]

If this is not intuitive to you then it may be best for you to discover this hands-on:

Get a flat, rectangular piece of material (thin sheetmetal if you have it, or even just cardboard).

See how easy it is to bend it along its long axis with no flange.

Now bend up along both long edges 90 degrees, (like a cable tray flange), and try bending it now.

 

[AlephZero]

When you have tried the experiment in #5, think how "floppy" something like a 3 meter long section of tray would be, and how easily it could be damaged when transporting it and installing it, without flanges.

 

[hisham.i]

Agreed that it will provide more strength on horizantal forces, but how it will affect the loading?

You would probably only use non-return flange in cases where loading was minimal and you wanted to save a little money.

as "the_emi_guy".

Since return flange will not provide any strength for the loading capacity.

 

[Manian M R S]

I agreed with the point of thinking of hisham.i..
How can the return flange give additional strength to the cable loading part (bottom part) of the cable tray...?
Can anyone share the mechanical strength Comparison calculations for the types...?
And also can anyone know how to calculate the the distance between and the type of supports for cable tray...?
Please share the details it would be very much useful for everyone..!

Thanks in advance,
Manian M R S

 

[dlgoff]

I just added this Cable Tray Systems post to the pinned Useful EE Links and Search Engines thread.