 |
|
|
 |
| Selection of Air Valve Size |
The Air Valves size can be selected 1/5 of the diameter of the main pipe for quick sizing as a thump rule.
The recommended Air Valves sizes according to pipe diameter is given below:
| Pipe Diameter MM |
80 - 250 |
300 - 400 |
450 - 550 |
600 - 1200 |
1250 - 2400 |
Above 2400 |
| Air Valve Diameter. MM |
50 - 80 |
80 - 100 |
100 - 150 |
150 - 200 |
200 - 250 |
250 - 300 |
The flow capacity of Air Valve should be at least one to one and half times of the filling rate of water in the pipe line. The flow capacity of Air Valve varies from manufacturer to manufacturer.
The flow capacity of Air Valve is calculated as below :
Qa = Ao*Co*(2*Diff.P)^0.5
|
Where |
Qa – Air Flow Capacity in Cubic meter per hour. |
|
Ao – Orifice Area in Sq.mm. Refer Table.1. |
|
Co – Coefficient of orifice. Refer Table.1. |
|
Diff.P – Differential Pressure across the Air Valve in Kg. Per Sq.cm. |
Table.1.
| Air Valve Size in mm |
50 |
80 |
100 |
150 |
200 |
| Area of orifice (Ao) in Sq. mm. |
615 |
1385 |
2641 |
13678 |
13678 |
| Coefficient of orifice (Co) |
0.85 |
0.85 |
0.85 |
0.85 |
1.35 |
Table.2.
|
Air Valve
Size
in mm |
Air Flow Rate (Qa) in Cub. Meter Per Hour |
|
Differential pressure (Diff.P) Kg. Per Sq. Cm. |
|
0.8 |
0.7 |
0.6 |
0.5 |
0.4 |
0.3 |
0.2 |
0.1 |
|
50 |
662 |
619 |
573 |
523 |
468 |
405 |
331 |
234 |
|
80 |
1489 |
1393 |
1289 |
1177 |
1053 |
912 |
744 |
526 |
|
100 |
2839 |
2656 |
2459 |
2245 |
2008 |
1739 |
1420 |
1004 |
|
150 |
14706 |
13756 |
12736 |
11626 |
10399 |
9006 |
7353 |
5199 |
|
200 |
23357 |
21848 |
20227 |
18465 |
16516 |
14303 |
11678 |
8258 |
If there are no other constraints, use maximum differential pressure of 0.35 Kg/Sq.Cm (5 PSI) for sizing to avoid excessive noise and other nuisances.
It is recommended to install Big Orifice Kinetic Air Valve / Tamper Proof Air Valve along with Small Orifice Automatic Air Valve at All Peaks, All points where there is change in gradient and Every 1500 Feet on low gradient long pipe lines. It is also recommended to install Small Orifice Automatic Air Valve at Every 500 Feet.
If the desired capacity cannot be achieved with a single Air Valve the valves can be placed in clusters – up to four air valves – on a single vent pipe from the main pipe. |
|
|
Registered office at:
1404, Elitis, Lodha Aurum Chs. Ltd.,
Kanjurmarg (E), Mumbai - 400 042
Mobile: 9322593122 / 9821466441
e-mail : amflow@hotmail.com
Web site : www.amflowtechnologies.com
Factory at:
Unit No.1, Dharam Raj Industrial Estate,
Descent Soap Compound, Lake Road,
Bhandup (W), Mumbai 400 078.
Mobile: 9322593122 / 9821466441
|
| An ISO 9001 certified company |
|
 |
