Filters; Pressure Regulating Valves (Prv's) - Netafim Techline CV Design Manual

N E T A F I M T E C H L I N E
BASIC
DESIGN
STEPS
(continued)
14

FILTERS:

• Just like overhead irrigation, dripperline needs protection against dirt and debris. (In sprinkler heads,
filters are placed under the drive assembly or nozzle. With drip and dripperline, one filter is placed at
the beginning of the zone, or at the POC).
• Filters are normally installed immediately downstream of the remote control valve.
• Netafim uses a non-collapsing stack of flat grooved discs that effectively capture contaminants.
• They are easily removed from the filter body and flushed clean under a faucet or in a pail of clean
water.
• Disc filters come in a variety of sizes and filtering capacities.
• Rule of Thumb: Use 120 or 140 mesh filters for Techline CV designs. Techline CV only requires 120
mesh filtration. If a finer mesh filter is used, it may require more frequent cleanings.
• Refer to "DISC FILTER SIZING CHART" on page 28 to properly size the filter.

PRESSURE REGULATING VALVES (PRV'S):

Pressure Regulating Valves reduce the operating pressure so that Techline CV zones operate
between 15 and 45 psi.
• PRVʼs are normally installed immediately downstream of the disc filter and remote control valve.
Often all three components are in the same valve box, and the distance from the PRV to the Techline
CV is limited so additional friction is not incurred.
• The two most popular sizes of PRV are both
range of 0.25 - 4.4 GPM. The High Flow version has a flow range of 3.5 - 17.6 GPM. Other sizes
from 1 1 " - 3" are also available for zones with flows up to 200 GPM.
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2
• To select the correct PRV, choose the model that has the correct flow range based on total zone flow.
• Then select the correct pressure rating based on the following:
1. If you used the "Maximum Length of a Single Techline CV Lateral" chart, (Table 2) match the PRV
to the same pressure rating you used for your maximum lateral length calculation,
OR
2. Simply use a 45 psi PRV. (Because Techline CV is pressure-compensating, there is no reason to
intentionally reduce the pressure below 45 psi).
NOTES:
1. If the PRV is remotely located from the supply header, remember to account for any friction loss
that occurs through the piping to the supply header.
2. Low Volume Control Zone Kits:
• These preassembled kits speed installation and have all of the components needed for a low
volume zone.
• Kits are sized for a specific flow range
C V D E S I G N G U I D E
®
3 / " units. One is a Low Flow version that has a flow
4