Bending pipe 90 degrees (Accurately)

[wilhelm]

neverrrrrrrrrrrrrrrr!!!!!!!!!!!!!!!!!!!!

 

[kevplumb]

man after my own heart

 

[wilhelm]

 

[kevplumb]

 

[Henny]

thanks again guys,

Yep your right I am referring to the bend allowance. The give a measurement say 200mm from the centre of the bend and on the right angle of the bend they say 180mm. When I'm bending I seem to be over or under, and as they will not let you use a pipe cutter in class it becomes a real pain in the preverbial when using a hacksaw. The pipe has to mesaure 200mm from the centre and 180mm from the centre on the other angle. If I use half the diameter of a 15mm pipe: being 7.5mm added on this still does not make the other measurements accurate. I'm not being a goody two shoes but I think the tutors method of instruction is poor and I'm struggling to grasp an accurate bend. Thanks to Kevplum and wihem for earlier input but does this shed anymore light. I seem to get more help from you guys on here that the actual tutors at college.

Thanks in advance

Henny

 

[brumylad]

Sounds like an unrealistic and very time consuming practice to follow when doing an installation to me.

Anyway, to give you an idea of the principle involved using the bender to achieve a degree of accuracy I'll explain my way of doing an accurate U-bend using 2 x 90' bends. It is as follows

1. mark on the pipe the centre to centre distance

2. insert pipe into bender, insert the former and pull together the arms of the bender so that the pipe is fixed against the hook.

3. have to hand an ~12' length of pipe the same diameter as that being bent which has been cut dead straight using a pipe cutter.

4. insert this length of pipe into the fixed curved former so that it meets the pipe being bent exactly perpendicluar.

5. move the pipe being bent so your first mark meets that wall of the short piece of pipe closest to you. now do your first 90' bend.

6. repeat the procedure to do the second bend but this time your mark should meet the wall of the short pipe which is furthest away from you.

Doing this will give you an idea of the principle involved using the bender to achieve a degree of accuracy

I was taught to use actual measurements only rarely, it is faster and more accurate to mark the pipe by "dead reckoning".

 

[htgeng]

another born again non-bender here. I can't be doing with them benders anymore!

A box of elbows everytime.

 

[Henny]

Hi guys,

Thanks for the replies from Brumylad & htgeng. I totally agree with you both but, this is an NVQ course starting from the basic - basics. Whether their trying to thin us out with boredom I don't know, they won't even let us use pipe cutters.

There giving us a length of pipe which is say 450mm and telling us they want a 90 degree bend, one side being 160mm & the other being 220mm with only minimal pipe to play with. There is a formula wher you measure the first length, in this case 160mm and then you add twice the diameter or radius orrrrrrr 4 times the diameter. It's horses for courses and we have to do it but I just don't know the formula??????

Thanks

Henny

 

[brumylad]

practice the method I describe. It is far more accurate than any measurement and formula's. It is a solution that will give you the result you want, honest.

 

[kevplumb]

try this
http://www.ukcopperboard.co.uk/public/howcanwehelp/inst_tips3_contents_list.shtml

 

[Bahco]

l I seem to get more help from you guys on here that the actual tutors at college.

Henny

You at Wolverhampton college too

 

[kevplumb]

am i missing something here ?
whats wrong with bilston

 

[Bahco]

Same thing marra only City of Wolverhampton College sounds more upmarket

 

[Henny]

I 'm at Boston, Lincolnshire guys

Henny

 

[doblo7]

Hi,
I've just passed my pipe installation examination, which requires to bend a pipe 90 degrees to fixed measurements.
This is the method, using your example measurements:

There giving us a length of pipe which is say 450mm and telling us they want a 90 degree bend, one side being 160mm & the other being 220mm with only minimal pipe to play with. There is a formula wher you measure the first length, in this case 160mm and then you add twice the diameter or radius orrrrrrr 4 times the diameter. It's horses for courses and we have to do it but I just don't know the formula??????

Always mark one end of the pipe, this is called the fixed point. From there measure the length you require, your example 160mm, then take off twice the tube diameter which is 30mm if using 15mm copper tube. From this point ie 130mm from the fixed point insert copper tube with the fixed point sticking out the right end of pipe benders (which is refered to the front of the pipe bender). Align the mark (130mm) so that it is in line with the edge of the former, use a set square sitting on the guide touching edge of former and make sure marked point of 130mm is in line with set square edge. Then just bend pipe. one end will be 160mm as required. If you want other end to be to a specific measurement and are not allowed just to measure and trim off excess then what you first need to do is add the two measurements you are given ie 160 and 220, take off twice the pipe diameter (30mm for 15mm copper tube). the length of pipe you will need will be 160+220-30=350mm. Now when you bend as above instructions on 160 length the remainding tube will be exactly 220 on the other end. Try it if you don't believe me..it will work because I just tried it in my workshop to be sure. Finally join the copper club at www.ukcopperboard.co.uk and you'll get a free cd rom which will be invaluable in passing the practical and written exams you'll be doing.
Please let me know you tried it, copper tube is cheap to buy always practice the best way of learning.[/quote]