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Irrigation Pipes

The document explains Standard Dimension Ratio (SDR) and schedule numbers (SCH) for pressure piping, detailing how SDR indicates the relationship between pipe diameter and wall thickness, while SCH relates to wall thickness across different pipe sizes. It also covers pressure nominal (PN) ratings for PE pipes, temperature considerations for PVC, and notes on pipe dimension tables including hydrostatic design stress. Key points include maximum service temperatures and pressure ratings for various pipe specifications.

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ahmed.0.0.sherif
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23 views21 pages

Irrigation Pipes

The document explains Standard Dimension Ratio (SDR) and schedule numbers (SCH) for pressure piping, detailing how SDR indicates the relationship between pipe diameter and wall thickness, while SCH relates to wall thickness across different pipe sizes. It also covers pressure nominal (PN) ratings for PE pipes, temperature considerations for PVC, and notes on pipe dimension tables including hydrostatic design stress. Key points include maximum service temperatures and pressure ratings for various pipe specifications.

Uploaded by

ahmed.0.0.sherif
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
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 WHAT IS SDR-PR ?

 Standard Dimension Ratio - SDR - as method of rating


pressure piping such as SDR 26,21,13.5
 A SDR 11 means that the outside diameter - D - of the pipe is eleven
times the thickness - s - of the wall. As a consequence a high SDR
pipe has a low-pressure rating and low SDR pipe has a high-pressure
rating.
 SDR = D / s (1)
 where
 D = pipe outside diameter (mm, in)
 s = pipe wall thickness (mm, in)
 WHAT IS THE MEANING OF SCH ?
 The schedule number on pipe products relates to the thickness of the wall on the
pipesuch as SCH 40 , SCH 80 .
 as the number increases, the thicker the wall thickness becomes. Also, while the
schedule number can be the same on different sized pipes, the actual wall
thickness will be different
 Pipe size 1.000” Schedule 40 – The actual wall thickness is 0.133”
 Pipe size 2.000” Schedule 40 – The actual wall thickness is 0.145”
 Pipe size 1.000” Schedule 80 – The actual wall thickness is 0.179”
 Pipe size 2.000” Schedule 80 – The actual wall thickness is 0.218”
Comparison SCH 40,80,120
Temperature Considerations

 EXAMPLE: 10" PVC SCHEDULE 80 @ 49° C = !!!

 230 psi x 0.40 = 92 psi max. @ 49° C

 THE MAXIMUM SERIVCE TEMPERATURE FOR PVC IS 140°F / 60 C.


 Pressure Nominal - PN
 PE pipes are produced in different pressure grades (PN grades),
which indicates the pressure in bars the pipe can support with water
at 20 oC.
 The pressure grades available according to European standards are
 PN 2.5 - max pressure 2.5 bar
 PN 4 - max pressure 4 bar
 PN 6 - max pressure 6 bar
 PN 10 - max pressure 10 bar
 PN 16 - max pressure 16 bar
Note:
1. d = outside diameter of pipe
s = wall thickness of pipe
PN = Nominal pressure rating, in
bar at 20ºC
2. Pipe weight per 1 meter is
estimated by using pipe density at
0.952 gm/cm3.
3. Standard lenght is 6 meters, but
for small size, 16 mm - 110 mm it
can be coiled at the length of 50
and 100 m per coil.
 Notes on Pipe Dimension tables:
 HDS (Hydrostatic Design Stress), in (MPA), is obtained by applying a
design factor of not less than 1.26 to the minimum required strength
value of the pipe.
 minimum required strength value of the pipe. design safety factor
from 1,26 to 1,6.
Temperature Considerations

 The maximum recommended working temperature is 50°C


Comparison

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