Rate-Of-Flow Control
Flow Direction
Upstream
800 Series Valve
H2 External Filter
Upstream
Manual Selector Valve
Thread into control chamber
Flow Adjustment
Screw
Flow Sensing Paddle
TO OPEN THE VALVE
COMPLETELY REMOVE
THIS PLUG AND SELECT
THE OPEN POSISTION
Pressure
Sustaining/
Relief Control
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
800PSFC4 - 3/05
D
800 SERIES CONTROL VALVE — CONTROL FUNCTION and MAINTENANCE
PRESSURE SUSTAINING/RELIEF & RATE-OF-FLOW
Valve Control Function:
The
PRESSUREPRESSURE
PRESSUREPRESSURE
PRESSURE
SUSTAININGSUSTAINING
SUSTAININGSUSTAINING
SUSTAINING
//
//
/
RELIEFRELIEF
RELIEFRELIEF
RELIEF
RATERATE
RATERATE
RATE
--
--
-
OFOF
OFOF
OF
--
--
-
FLOWFLOW
FLOWFLOW
FLOW
model of the 800 Series Control Valve is a hydraulically operated sleeve
type valve with a pressure sustaining/relief pressure control and a Rate-Of-Flow control. The flow through the valve is
controlled by a rubber sleeve which is actuated by hydraulic pressure responding to the controls as listed here:
· When the selector is pointed to the "
AUTO" position then the control functions will control the valve. Pointing the manual selector
handle to "
OPEN" will override the "AUTO" control. Pointing the manual selector valve to "CLOSE" will always close the valve.
· The pressure sustaining/relief pilot controls the valve to automatically open in the event the upstream pressure goes
higher than the control set pressure. Both the sustaining/relief and Rate-Of-Flow controls work together and the valve
responds depending upon the adjustment screw setting of both controls and also depending upon the system available
flow. Use this table to get the desired results:
· The Rate-Of-Flow control senses the flow by means of a paddle. The Rate-Of-Flow function depends on flow rate and
not on pressure. The Rate-Of-Flow adjustment screw is normally set to the desired flow to limit the flow through the valve.
The Rate-Of-Flow serves no function if the pressure on the upstream side of the valve is lower than the set point of the
pressure sustaining/relief pilot.
· Pointing the Manual Selector handle mid way between "OPEN" and "CLOSE" will lock the valve sleeve in position.
Size* Range of Flow Control adjustment
3” 120 GPM (27 M
3
/Hr) - 400 GPM (91 M
3
/Hr)
4” 200 GPM (45 M
3
/Hr) - 540 GPM (122 M
3
/Hr)
6” low flow 330 GPM (75 M
3
/Hr) - 1000 GPM (227 M
3
/Hr)
8” low flow 490 GPM (111 M
3
/Hr) - 1500 GPM (341 M
3
/Hr)
6” ** 500 GPM (114 M
3
/Hr) - 2000 GPM (454 M
3
/Hr)
8” ** 900 GPM (204 M
3
/Hr) - 3800 GPM (863 M
3
/Hr)
*Pipe diameter **In-Valve option available
Pressure upstream Water available to Rate-Of-Flow Valve Status
If lower than pilot set point. None Closed.
If higher than pilot set point. Less than flow setting. Open - upstream pressure will be maintained.
If higher than pilot set point. More than flow setting. Partially open - upstream pressure will go higher than set.*
*Caution on this condition if the system pressure is capable of rising to a dangerous point and causing damage.
The information on this sheet is for the
PRESSUREPRESSURE
PRESSUREPRESSURE
PRESSURE
SUSTAININGSUSTAINING
SUSTAININGSUSTAINING
SUSTAINING
//
//
/
RELIEFRELIEF
RELIEFRELIEF
RELIEF
RATERATE
RATERATE
RATE
--
--
-
OFOF
OFOF
OF
--
--
-
FLOWFLOW
FLOWFLOW
FLOW
control function with both internal
and external filter options (items D5,D8-D9, D18, H2 & H3
control function on the VALVE SELECTION GUIDE apply to this sheet).
NOTE: Better valve operation and
accuracy will result by avoiding pipe
size change, flow meters, pumps and
elbows immed-iately upstream of the
Rate-Of-Flow paddle. A straight length
of five pipe diameters helps improve
accuracy and valve performance.
(See inside for TROUBLE
SHOOTING
information and
back page for a schematic
with an internal filter.)
Pressure
Adjustment Screw
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