Nelson 800 Series User manual

Nelson Irrigation Corp. 848 Airport Rd. Walla Walla, WA 99362-2271 U A Tel: [phone] Fax: [phone] E-mail: [e-mail] Web site: www.nelsonirrigation.com
VALVE CONTROL FUNCTION:
The PRESSURE REDUCING ELECTRIC RATE-OF-FLOW model of the 800 Series Control Valve is a hydraulically operated sleeve type valve
with a pressure reducing pressure control, an electric solenoid for on/off and a Rate- f-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 electric solenoid is used to automatically open or close the valve.
The 3-way electric solenoid must be energized to open the valve and de-energized to close the valve. Pointing the manual
selector handle to "OPEN" will override the "AUTO" control and bypass the electric solenoid functions. Pointing the manual
selector valve to "CLOSE" will always close the valve.
·The Rate- f-Flow control senses the flow by means of a paddle. The Rate- f-Flow function depends on flow rate and not
on pressure. The Rate- f-Flow adjustment screw is normally set to 120% of design flow to limit the flow during system start
up. After the system is filled and back pressure is available then the pressure reducing control takes over to control the
downstream pressure. If the Rate- f-Flow setting is less than design flow rate then the Rate- f-Flow retains control to hold
the flow rate down and keep the valve from fully opening. The pressure reducing control serves no function if the Rate-
f-Flow is set less than design flow rate.
·The pressure reducing pilot controls the valve to automatically reduce a higher inlet pressure to a constant lower
downstream pressure. The pressure reducing control is adjustable to give the desired constant down stream pressure even
with fluctuating upstream pressure.
·When the selector is pointed to "OPEN" the pressure reducing and Rate- f-Flow controls still function but the solenoid has
no effect.
·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 PRESSURE REDUCING ELECTRIC RATE-OF-FLOW control function with both internal and external
filter options (items D2 through D4, D18, E20 - E70, H2 & H3 control function on the VALVE SELECTION GUIDE apply to this sheet .
800REFC4 D
E
800 SERIES CONTROL VALVE  CONTROL FUNCTION and MAINTENANCE
PRESSURE REDUCING ELECTRIC RATE-OF-FLOW

Nelson Irrigation Corp. 848 Airport Rd. Walla Walla, WA 99362-2271 U A Tel: [phone] Fax: [phone] E-mail: [e-mail] Web site: www.nelsonirrigation.com
800 SERIES CONTROL VALVE  PRESSURE REDUCING ELECTRIC RATE-OF-FLOW 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 " " 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.
SYMPTOM: The valve opens to let excessive amount of water flow more than the Rate-of-Flow setting.
CHECK ITEMS: bCheck the Rate-of-Flow sensing paddle for damage. If damage is found then repair
the paddle.
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" (8970-00 ) 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 P nt
3" 1 Cup
2" 5 oz (145ml)
8/02

SYMPTOM: Electric solenoid will not open or close the valve when in AUTO control mode.
CHECK ITEMS: bCheck that the valve can be opened or closed manually. Verify that there is power to the
solenoid. The solenoid must have power to open the valve.
bDisassemble the solenoid to make sure the plunger is not stuck and check the coil for
continuity. If the solenoid coil is burned out then replace the coil.
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 a Nelson ACV200 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.
bChange the BLUE sensitivity bushing to RED or BLACK in order to change the valve response
to the pressure swing cycles.
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 U A Tel: [phone] Fax: [phone] E-mail: [e-mail] Web site: www.nelsonirrigation.com
8/02
800 SERIES CONTROL VALVE  PRESSURE REDUCING ELECTRIC RATE-OF-FLOW CONTROL
TROUBLE SHOOTING GUIDE

Nelson Irrigation Corp. 848 Airport Rd. Walla Walla, WA 99362-2271 U A Tel: [phone] Fax: [phone] E-mail: [e-mail] Web site: www.nelsonirrigation.com
800 SERIES CONTROL VALVE  PRESSURE REDUCING ELECTRIC RATE-OF-FLOW CONTROL
TROUBLE SHOOTING GUIDE
8/02
SYMPTOM: The valve will not open adequately to build the desired pressure on the downstream side
of the valve.
CHECK ITEMS: bCheck that the Rate-Of-Flow adjustment screw setting is set slightly greater than the
design flow rate (usually 120% of design). If the setting is lower than the design flow then
the down stream pressure will not rise adequately to reach the pressure desired. 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 the Rate-
Of-Flow is in control of the valve. Change the adjustment setting of the pressure reducing
control and/or the Rate-Of-Flow control to get the desired results.
WARRANTY AND DISCLAIMER: Nelson Irrigation Corporation 800 Series Control Valves are warranted for one year from date of original sale to be free
of defective materials and workmanship when used within the working specifications for which the product was designed and under normal use and service.
he manufacturer assumes no responsibility for installation, removal or unauthorized repair. he manufacturers liability under this warranty is limited solely
to replacement or 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. HIS WARRAN Y IS EXPRESSLY IN LIEU OF ALL O HER WARRAN IES, EXPRESS OR IMPLIED, INCLUDING HE WARRAN IES OF
MERCHAN ABILI Y AND FI NESS FOR PAR ICULAR PURPOSES AND OF ALL O HER OBLIGA IONS OR LIABILI IES OF MANUFAC URER. 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.
PRESSURE REDUCING ELECTRIC RATE-OF-FLOW SCHEMATIC SHOWING INTERNAL FILTER