Nelson 800 Series Manual

Valve Control Function:
The
PRESSURE SUSTAINING PRESSURE PRESSURE PRESSURE PRESSURE SUSTAINING SUSTAINING SUSTAINING SUSTAINING
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 "
handle to " " will override the "
OPEN
· 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:
Pressure upstream
If lower than pilot set point.
If higher than pilot set point.
If higher than pilot set point.
*Caution on this condition if the system pressure is capable of rising to a dangerous point and causing damage.
· 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.
The information on this sheet is for the
- - - - - - - - - - control function with both internal
RELIEF RATE RELIEF RELIEF RATE RATE RATE OF OF OF FLOW FLOW FLOW
RELIEF RELIEF RATE OF OF FLOW FLOW
and external filter options (items D5,D8-D9, D18, H2 & H3
control function on the
Size* Range of Flow Control adjustment
3" 120 GPM (27 M
4" 200 GPM (45 M
6" low flow 330 GPM (75 M
8" low flow 490 GPM (111 M
6" ** 500 GPM (114 M
8" ** 900 GPM (204 M
*Pipe diameter **In-Valve option available
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.
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 — CONTROL FUNCTION and MAINTENANCE
PRESSURE SUSTAINING/RELIEF & RATE-OF-FLOW
/ / / / / - - - - - - - - - - model of the 800 Series Control Valve is a hydraulically operated sleeve
RELIEF RELIEF RELIEF RATE RELIEF RELIEF RATE RATE RATE RATE OF OF OF OF OF FLOW FLOW FLOW FLOW FLOW
" position then the control functions will control the valve. Pointing the manual selector
AUTO
" control. Pointing the manual selector valve to "
AUTO
Water available to Rate-Of-Flow
None
Less than flow setting.
More than flow setting.
PRESSURE SUSTAINING PRESSURE PRESSURE PRESSURE PRESSURE
apply to this sheet).
VALVE SELECTION GUIDE
/Hr) - 400 GPM (91 M
3
/Hr) - 540 GPM (122 M
3
/Hr) - 1000 GPM (227 M
3
/Hr) - 1500 GPM (341 M
3
/Hr) - 2000 GPM (454 M
3
/Hr) - 3800 GPM (863 M
3
Manual Selector Valve
Thread into control chamber
Rate-Of-Flow Control
Flow Adjustment
Screw
Flow Sensing Paddle
Valve Status
Closed.
Open - upstream pressure will be maintained.
Partially open - upstream pressure will go higher than set.*
/ / / / /
SUSTAINING SUSTAINING SUSTAINING SUSTAINING
Upstream
/Hr)
3
/Hr)
3
/Hr)
3
Upstream
/Hr)
3
/Hr)
3
/Hr)
3
800PSFC4 - 3/05
" will always close the valve.
CLOSE
(See inside for
TROUBLE
information and
SHOOTING
back page for a schematic
with an internal filter.)
H2 External Filter
TO OPEN THE VALVE
COMPLETELY REMOVE
THIS PLUG AND SELECT
THE OPEN POSISTION
Pressure
Sustaining/
Relief Control
Pressure
Adjustment Screw
800 Series Valve
Flow Direction
D