Nelson 800 Series User manual

Nelson Irrigation Corp. 848 Airport Rd. Walla Walla, WA 99362-2271 USA Tel: [phone] Fax: [phone] E-mail: [e-mail] Web site: www.nelsonirrigation.com
VALVE CONTROL FUNCTION:
The PRESSURE REDUCING MANUAL ON-OFF model of the 800 Series Control
Valve is a hydraulically operated sleeve type valve with a pressure
reducing pressure control kit and a manual on-off. The flow through
the valve is controlled by a rubber sleeve which is actuated by
hydraulic pressure. When the selector is pointed to the "AUTO" position
then the valve will automatically reduce a higher inlet pressure to a
constant lower downstream pressure. The pressure reducing control
is adjustable to give a constant down stream pressure even with
fluctuating upstream pressure. The manual selector is used to
manually open or close the valve. Pointing the manual selector
handle to "OPEN" or "CLOSE" will override the "AUTO" control. Pointing the
Manual Selector handle mid way between "OPEN" and "CLOSE" will
hold the valve partly open.
The information on this sheet is for the PRESSURE REDUCING MANUAL ON-
OFF control function with plastic tubing and internal or external filter
option (items D2 - D4, D12-D13, E1, H2 - H3 control function on
the VALVE SELECTION GUIDE apply to this sheet).
800PR5
800 SERIES CONTROL VALVE — CONTROL FUNCTION and MAINTENANCE
PRESSURE REDUCING MANUAL ON-OFF
D
MANUAL
SELECTOR
INTERNAL
FILTER
PRESSURE
REDUCING
CONTROL
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Nelson Irrigation Corp. 848 Airport Rd. Walla Walla, WA 99362-2271 USA Tel: [phone] Fax: [phone] E-mail: [e-mail] Web site: www.nelsonirrigation.com
800 SERIES CONTROL VALVE — PRESSURE REDUCING MANUAL ON-OFF CONTROL
TROUBLE SHOOTING GUIDE
SYMPTOM: Valve will not close when the manual selector valve is in the “CLOSE” position.
CHECK ITEMS: bCheck for leaks on all tube lines and fittings. If it is
necessary to remove any control tube lines from the fittings
then use an opposing force as shown here. Pull the tube
while pressing in the opposite direction on the fitting ring.
bCheck that water can flow through the tube "U" which
connects the upstream (high pressure) side of the main
valve to the “CLOSE” port of the manual selector valve. Refer
to the control function diagram. If little or no flow, find the
reason for the blockage and clear it.
bCheck the filter to assure it can pass adequate water flow. This can be deceptive
because when you unhook the line from the filter some water can still flow. A partially
blocked filter will reduce the valve closing response time. If little or no flow is present then
clean the filter. If the valve is equipped with an external filter open the valve on the filter
to clean the filter.
bCheck the sleeve for damage. To do this, point the
manual selector valve to the “OPEN” position. The total
volume of water that should flow from the sleeve
chamber through the “OPEN” port is the same as the
volume required to fully open or close the valve. If more
than this volume of water continues to flow, then the
sleeve has been punctured and must be replaced.
SYMPTOM: Valve will not open or has excessive pressure drop when the manual selector valve is in
the “OPEN” position.
CHECK ITEMS: bCheck all tube lines and fittings for blockages and kinks. If there are no obstructions
then check that upstream pressure is adequate. The 200 psi rated valve starts to open at
8 psi and is fully open at 30 psi. The 80 psi rated valve starts to open at 10 psi and is fully open
at 18 psi. The 50 psi rated valve starts to open at 8 psi and is fully open at 10 psi.
bCheck the total volume of water in the sleeve chamber to verify that enough water volume
(see table) flows between fully open and fully closed. This water volume can be measured
as it flows from the “OPEN” port. If there is still a large pressure drop across the valve then
debris could be caught blocking the flow on the upstream side of the cage. This type of
obstruction will require removing the valve from the line and cleaning out the debris.
CAUTION! BE CAREFUL TO SHUT DOWN PRESSURE ON THE SYSTEM BEFORE SERVICING THIS
VALVE! IF THE VALVE IS CLOSED AND UNDER PRESSURE, DISCONNECTING THE CONTROL
TUBE "U" (8970-005) WILL CAUSE RAPID OPENING OF THE VALVE! SYSTEM DAMAGE COULD OCCUR!
!!
!!
!
WATER VOLUME REQUIRED TO
FULLY OPEN OR CLOSE VALVE
8" 4 Quarts
6" 2 Quarts
4" 1 Pint
3" 1 Cup
2" 5 oz (145ml)
3/02

SYMPTOM: 800 Series valve will not pressure regulate.
CHECK ITEMS: bCheck all tube lines and fittings are connected as shown on the diagram and that all
isolation valves are in the open position.
bCheck that the regulating 9358 spool valve inside the 9529 pressure control is not stuck.
This spool valve must be free to move in response to down stream pressure. Inspect the spool
valve by unscrewing the sensitivity bushing assembly as shown in this drawing.
bCheck the filter to assure it can pass adequate water flow. A partially blocked filter will reduce
the valve regulating and closing response time. If little or no flow is present then clean the filter.
SYMPTOM: The regulated pressure is unstable (fluctuating high and then low several times a minute) and
water is discharged from the exhaust port during each low pressure cycle.
CHECK ITEMS: bCheck for trapped air in the pipe system down stream from the 800 Series valve. This
problem is not easily detected. The installation of an automatic air release valve will help rid
the system of trapped air. It is recommended this type of air release valve be installed at high
elevation points on the system where air could accumulate. Typical location for the
accumulated air is shown.
Note: Be sure to drain the system to reduce the potential of winter freeze damage.
Nelson Irrigation Corp. 848 Airport Rd. Walla Walla, WA 99362-2271 USA Tel: [phone] Fax: [phone] E-mail: [e-mail] Web site: www.nelsonirrigation.com
3/02
800 SERIES CONTROL VALVE — PRESSURE REDUCING MANUAL ON-OFF CONTROL
TROUBLE SHOOTING GUIDE

Nelson Irrigation Corp. 848 Airport Rd. Walla Walla, WA 99362-2271 USA Tel: [phone] Fax: [phone] E-mail: [e-mail] Web site: www.nelsonirrigation.com
800 SERIES CONTROL VALVE — PRESSURE REDUCING MANUAL ON-OFF CONTROL
SCHEMATIC WITH EXTERNAL FILTER
3/02