Nev. Admin. Code § 444.8396 - Pressure distribution system: Design criteria

1. A pump must be used to pressurize a pressure distribution system. A siphon may be used in lieu of a pump if adequate elevation head is available. The active dosing volume must be approximately 10 times the total volume of the distribution pipe.

2. A solid delivery pipe which goes from the dosing tank to the perforated distribution piping must be placed below the frost line. The delivery pipe must maintain a downward slope from the distribution lines to the dosing tank to ensure that the line will drain between discharges. Check valves and other devices that prevent backflow through the pump must not be used so that effluent may, when necessary, drain back to the dosing tank to protect the pipe from freezing.

3. To reduce the potential for plugging and clogging the distribution lines, the diameter of the discharge hole must be 3/8 inch or more. The rate of discharge for various-sized holes at various pressures are set forth in the following table:

DISCHARGE RATES AT VARIOUS PRESSURES (gallons per minute)
Pressure		Hole Diameter
Per Foot of Water	Per Square Inch	3/8 Inch	7/16 Inch	1/2 Inch
1	0.43	1.66	2.26	2.95
2	0.87	2.34	3.19	4.17
3	1.30	2.87	3.91	5.10
4	1.73	3.31	4.51	5.89
5	2.17	3.71	5.04	6.59

4. Friction losses in schedule 40 plastic pipe are listed in the following table:

FRICTION LOSS IN SCHEDULE 40 PLASTIC PIPE; C = 150 (ft/100 ft)
	Pipe Diameter (inches)
Flow in gallons per minute	1	1 1/4	1 1/2	2	3	4	6	8	10
1	0.07
2	0.28	0.07
3	0.60	0.16	0.07
4	1.01	0.25	0.12
5	1.52	0.39	0.18
6	2.14	0.55	0.25	0.07
7	2.89	0.76	0.36	0.10
8	3.63	0.97	0.46	0.14
9	4.57	1.21	0.58	0.17
10	5.50	1.46	0.70	0.21
11		1.77	0.84	0.25
12		2.09	1.01	0.30
13		2.42	1.17	0.35
14		2.74	1.33	0.39
15		3.06	1.45	0.44	0.07
16		3.49	1.65	0.50	0.08
17		3.93	1.86	0.56	0.09
18		4.37	2.07	0.62	0.10
19		4.81	2.28	0.68	0.11
20-24		5.23	2.46	0.74	0.12
25-29			3.75	1.10	0.16
30-34			5.22	1.54	0.23
35-39				2.05	0.30	0.07
40-44				2.62	0.39	0.09
45-49				3.27	0.48	0.12
50-59				3.98	0.58	0.16
60-69					0.81	0.21
70-79					1.08	0.28
80-89					1.38	0.37
90-99					1.73	0.46
100-149					2.09	0.55	0.07
150-199						1.17	0.16
200-249							0.28	0.07
250-299							0.41	0.11
300-349							0.58	0.16
350-399							0.78	0.20	0.07
400-449							0.99	0.26	0.09
450-499							1.22	0.32	0.11
500-599								0.38	0.14
600-699								0.54	0.18
700-799								0.72	0.24
800-899									0.32
900-999									0.38
1000 or more									0.46

5. Laterals must be spaced so that they are not less than 4 feet or more than 6 feet apart. The outside laterals must be placed at a distance from the perimeter of the bed that is equal to 1/2 of the distance between the laterals.

6. Distribution lines in the pressure distribution system must be looped.

7. The required lateral pipe diameters for various hole diameters, hole spacings, and lateral lengths for plastic pipe are shown in the following diagram:

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8. Manifold diameters for various manifold lengths, number of laterals, and lateral discharge rates for plastic pipe are shown in the following diagram:

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Notes

Nev. Admin. Code § 444.8396

Added to NAC by Bd. of Health by R129-98, eff. 3-25-99

NRS 439.200, 444.650