Nelson 800 Series Manual

Nelson Irrigation Corp. 848 Airport Rd. Walla Walla, WA 99362-2271 USA Tel: 509.525.7660 Fax: 509.525.7907 E-mail: info@nelsonirrigation.com Web site: www.nelsonirrigation.com
800 SERIES CONTROL VALVE — PRESSURE SUSTAINING/RELIEF & RATE-OF-FLOW CONTROL
SCHEMATIC WITH INTERNAL FILTER
3/05
WARRANTY AND DISCLAIMER: Nelson 800 Series Control Valves and Accessories are warranted for one year from the date of original sale to be
free of defective material and workmanship when used within the working specifications for which the products was designed and under normal use and
service. The manufacturer assumes no responsibility for installation, removal or unauthorized repair of defective parts and the manufacturer will not be
liable for any crop or other consequential damages resulting from any defects or breach of warranty. THIS WARRANTY IS EXPRESSLY IN LIEU OF ALL
OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR PARTICULAR PURPOSES
AND OF ALL OTHER OBLIGATIONS OR LIABILITIES OF MANUFACTURER. No agent, employee or representative of the manufacturer has authority
to waive, alter or add to the provisions of this warranty nor to make any representations or warranty not contained herein.
SYMPTOM: The valve will not open adequately and then the upstream pressure goes higher than the
sustaining/relief pressure control setting.
CHECK ITEMS: bCheck that the Rate-Of-Flow adjustment screw setting is set for the correct flow. If the
setting is lower than the available flow then the valve will be held partially closed and
upstream pressure will rise. One method to evaluate the control status is to feel the control
tube connected to the "VALVE" port on the Rate-Of-Flow to determine if it is pressurized. If
it is pressurized then he Rate-Of-Flow is in control of the valve. Change the adjustment
setting on the Rate-Of-Flow or increase the amount the valve is opened. The pressure
sustaining/relief will then maintain the upstream pressure.
Flow Direction
Upstream
Manual Selector Valve
Thread into control chamber
800 Series Valve
Flow
Adjustment
Screw
Flow Sensing Paddle
Pressure
Sustaining/Relief
Control
H3 Internal Filter
Upstream
TO OPEN THE VALVE
COMPLETELY REMOVE
THIS PLUG AND SELECT
THE OPEN POSISTION
Pressure Adjustment
Screw

Nelson 800 Series Specifications

General

Brand	Nelson
Model	800 Series
Category	Control Unit
Language	English