How to work out fall need help!!??

[Has23]

Hi guys, wonder if you can help me, I am installing a ensign pipe 4" I got a drawing saying 1:80 IL how do I work out a fall? thanks any example will help

 

[Chalked]

I take that as 1m fall in 80m length.

 

[jonnyswamp]

So do I, so for every 80 inches, cm's or m's it travels, it must fall by 1 inch, cm or m
What is a ensign pipe

 

[ShaunCorbs]

So do I, so for every 80 inches, cm's or m's it travels, it must fall by 1 inch, cm or m
What is a ensign pipe

cast iron if im not mistaken ??????

 

[joni os]

1:80 , half inch fall per metre run, for those of us who still think imperial.

 

[rpm]

1:80 , half inch fall per metre run, for those of us who still think imperial.

Clever reply, was trying to remember the maths but gave up after 10 minutes.

 

[Deleted member 25704]

1:40 fall is 25mm drop every 1m in length

1:80 fall is 12.5mm drop every 1m in length

 

[rpm]

The original post said 1:80 IL and I haven`t the slightest clue what IL stands for but for those still puzzled .....

The maths is the same for all 1: x falls, in this case the number is 80 so 1000 divided by 80 = 12.5 and so 100 divided by 80 =1.25.