Page 318 - ToroProductCatalogue2016

Piping Flow Rates
318
Company
Flow Rates
One of the selection criteria Irrigation designers use to select pipe sizing for mainline pipe is to maintain the velocity of flow through the mainline pipe to be less than or equal to 1.5 m/s. Pressure rating and pressure loss are other criteria.
Tables 1 and 2 indicate flow rates in litres per minute for various PVC (AS 1477) and PE (AS/NZS 4130:1997) pipe sizes for a velocity of 1.5 metres per second.
Pipe sizing in sprinkler laterals (pipes downstream of the zone control valve) is based on maintaining the zone pressure to within a set tolerance. As a result, velocities in sprinkler laterals can sometimes need to be raised higher than 1.5m/s in an effort to balance friction loss and pressure gained
by elevation differences. This decision should only be undertaken by someone experienced in hydraulic design.
Table 3
Lateral Flow Rates for 2.0 m/s Velocity − PVC Pipe
PVC Pipe Size and Class
Maximum Flow (Lpm)
15mmcl15
30
20mmcl12
52
25mmcl12
82
32mmcl12
132
40mmcl12
173
50mmcl12
272
Table 1
Mainline Flow Rates for 1.5 m/s Velocity − PVC Pipe
PVC Pipe Size and Class
Maximum Flow (Lpm)
15mmcl15
23
20mmcl12
39
25mmcl12
62
32mmcl12
99
40mmcl12
130
50mmcl12
204
Table 4
Lateral Flow Rates for 2.0 m/s Velocity − PE80 PN 12.5
MDPE Pipe Size and Class
Maximum Flow (Lpm)
DN16
14
DN20
24
DN25
37
DN32
64
DN40
98
DN50
154
Table 2
Mainline Flow Rates for 1.5 m/s Velocity − PE80 PN 12.5
MDPE Pipe Size and Class
Maximum Flow (Lpm)
DN16
11
DN20
18
DN25
28
DN32
48
DN40
74
DN50
116
policy is one of constant improvement and therefore changes in specifications may be made without notice and without incurring liability. Please refer to www.toro.com.au Toro Australia Pty Ltd, 53 Howards Road, Beverley, South Australia, 5009. Phone 1300 130 898, fax (08) 8243 2488. A.B.N. 47 001 310 443