Determine the diameter of a suitable air main for the

Question

Using the nomogram and charts.

Types of fitting		Equivalent pipe length in m.
		Inner pipe diameter in mm.
		25	40	50	80	100	125	150
Seat valve		6-Mar	10-May	15-Jul	25-Oct	15-30	20-5C	25-60
Diaphragm valve		1.2	2	3	4.5	6	8	10
Gate valve		0.3	0.5	0.7	1	1.5	2	2.5
Elbow		1.5	2.5	3.5	5	7	10	15
Bend r=d		0.3	0.5	0.6	1	1.5	2	2.5
Bend r=2d		0.15	0.25	0.3	0.5	0.8	1	1.5
Hose connection T-piece		2	3	4	7	10	15	20
Reducer		0.5	0.7	1	2	2.5	3.5	4

Table of equivalent pipe lengths for valves and fittings as used on air distribution systems

Determine the diameter of a suitable air main for the distribution of 6 m³ min-1 FAD.

System pressure is 6 bar, the length of the pipe run is 175 metres, and a maximum pressure drop of 0.3 bar is allowed.

The distribution main must also include the following : . 4bends(r=2d) . 2 elbow fittings . 6 tee connectors . 2 diaphragm valves.