T e c h n i c a lN e w s l e t t e r

Special Issue Published by Rain Bird Sales, Inc. Turf Products Fall 2000

IN THIS ISSUE:Winterization

PRS-Dial Pressure Regulating Module

Your Guide to Winterization

If freezing temps are in your forecast, the time to act is now!

Winterizing your sprinkler system – removing water from the pipes, valves and sprinkler heads – is essential before freezing occurs. It’s the best way to protect yourirrigation investment from potentially serious damage this winter. You can choosefrom three winterization techniques:

• the manual drain valve method

• the automatic drain valve method or

• the compressed air blow-out method.

Read about each to determine the method best for your system.

IMPORTANT! No matter which method you choose, be sure to reference the ProtectingYour Controller in Winter section on page 5 to complete the winterization process!

Manual Drain Valve Method

Design: To use this method, your system must be properly designed. Make sure the manual drain valve is installed at the lowest point on your system’s mainline.Additional manual drain valves should be installed if your mainline has multiple lowpoints where water may collect. A ball valve, gate valve, “Stop and Waste” valve orsimple threaded pipe with a cap can provide drainage. Make sure piping is properly

o ti ued o i side spread

Protect Your Irrigation SystemFrom Winter Damage

Property photos compliments of Kathi Hiatt

For additional copies, please contactRod Waller, Authorized Service Centermanager, at 520-434-6259 or email:

rwaller@rainbird.com Electronic version is also available.

sloped to drain. If the valve is outdoors,it should be installed over a “dry well”(underground pit filled with gravel) todrain water away from the piping. If thevalve is installed indoors, make sure youcan drain a volume of water withoutflooding or overflow.

Procedure:

NOTE: Be sure to wear proper eye protec-tion and follow these steps carefully.The manual drain valve or drain cap is pressurized and can cause injury ifopened before the pressure is relieved.

Turn off the sprinkler system mainline shut-off valve ( A ).

Open one of the sprinkler systemcontrol valves, either manually or electrically from the controller, to relieve pressure on the sprinkler system mainline.

Slowly open the manual drain valve ( B ).

Repeat this procedure for all manual drain valves on the sprinklersystem mainline.

NOTES ABOUT REMOTE CONTROLVALVES: Draining valves using gravity oractivating the valves manually does notremove water captured inside thevalves. Valves must be disassembled toremove standing water (unless they arewinterized using blown compressed air).

Manual valves should be left in theopen position throughout winter to

prevent repressurization.

Some sprinkler heads have both sideand bottom pipe inlets. If you use theside inlet, install a drain valve on thebottom inlet to prevent the case fromfreezing. Sprinkler heads with built-incheck valves to prevent low headdrainage must be disassembled orblown out with air.

Now refer to the Protecting YourController in Winter section on page 5.

Automatic Drain Valve Method

NOTE: You MUST use the Manual DrainValve method for winterization of amainline. Never install automatic drainvalves on a sprinkler system mainline!

Description: The automatic drain valveis a spring-loaded device installed onsprinkler heads or lateral pipes. Thedrain valve opens every time the systemis shut off and drains all water from thepipe. When the system is pressurized,water presses against the sealing mechanism, shutting the valve andallowing water to flow through thepipe and to the sprinklers.

Design: Automatic drains should beinstalled after or downstream of thesprinkler control valves at the lowpoints in the sprinkler lines. Usually oneor two drains per line are adequate. Thedrain valves simply screw on using 1/2

or 3/4" male pipe threads. Teflon tapewrapped two or three times around the connection ensures a proper seal. A small dry well directly beneath thedrain assists with drainage for poorlydraining soil.

Procedure: Because automatic drainvalves remove water every time the sys-tem is shut off, no manual interventionis required for this stage of winterizing.Simply check for excessive puddling onthe soil surface, which may indicate thatone of the drains has become stuckopen during sprinkler operation.

As with the manual method, draining or activating remote control valves electrically from the controller does not remove water captured inside thevalves. Valves must be disassembled to remove standing water (unless youwinterize using blown compressed air).

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• Diaphragm-style valves – remove thebonnet, solenoid and diaphragmassembly; drain or sponge any standingwater; then reassemble. Leave the solenoid in open position for winter.

• Actuator-type valves – remove thestem and solenoid assembly. Leave allvalves in the manual open position allwinter to prevent repressurization.Open by turning the bleed screw orsolenoid counterclockwise.

NOTE: If your sprinkler heads are usingthe side inlet, or if you have built-incheck valves (SAM) on your sprinklers,see automatic drain valve method (pg. 2).

Reminder! Now refer to the Protecting Your Controller in Wintersection to complete winterization.

Compressed Air Blow-Out Method

Protect Your System! Protect Yourself!

CAUTION: WEAR PROPER EYE PROTECTION AND STAND CLEAR!

Use extreme care when blowing out the system. Excessive pressure(above 50 psi) can damage valves orsprinkler pipe or cause physical injuryfrom flying debris. Never stand overirrigation pipes, sprinklers or valvesduring this process.

Description: This method uses com-pressed air to clear water from themainline pipe, sprinkler control valves,lateral pipes and sprinkler heads. Localirrigation contractors usually offer thisservice for a reasonable fee, which mayalso include start-up in the spring.Depending on the size and type ofequipment used in your system, youmay want to choose a professional who is fully equippedto provide this service.

Selecting the Right Air Compressor

To obtain proper air volume, use a compressor capable of providing 10 to25 cubic feet per minute (CFM) of airvolume. It is very important to rent orbuy the right air compressor for the job.Some small shop compressors (2 hp)may not be adequate.

CAUTION: Air pressure must not exceed50 pounds per square inch (psi) duringthe blow-out procedure. Use a pressure-regulating valve to avoid overpressuriza-tion. Air volume should be high and airpressure low to minimize the potentialfor damage.

Do not try to use an air compressor withhigh pressure (120 psi) and low volumeto evacuate water from the system. Donot compensate for a small compressorby filling the compressor’s holding tankwhile the mainline is closed to create asurge of pressure to blow the line cleanwhen you open the sprinkler controlvalve. This dangerous practice placesvery severe stresses on all componentsof the system. Never run the compressorwithout at least one sprinkler controlvalve open.

NOTE: Even if the system can withstand120 psi of water pressure, similar airpressure will damage the system. Theviscosity of air is much lower thanwater, generating much higher stresses.

Design: Your sprinkler system mainlineshould offer a separate quick-connect

fitting, manual gate valve, plugged“tee,” or capped pipe in the linespecifically for the air hose (C in thediagram on page 2). This connection

should be located as close to the water source as possible. Check withyour air compressor manufacturer for the correct procedure and equipment hookup.

Procedure: Blow-out using a timer is safer than activating the valves manually. If your system has a timer,follow the guidelines described first.

16 A-FDVDrain Valve

Clean Gravel

Blow-out procedure activating sprinkler control valves USING THE CONTROLLER:

CAUTION: Wear proper eye protectionand never stand over irrigation pipes,sprinklers or valves during this process.

Close mainline sprinkler shut-offvalve ( A ).

Relieve the water pressure on themainline by activating a circuit or zonefrom your controller. Activate the circuitthat is furthest from the air connectionbefore letting air into the piping. Alwayskeep a sprinkler zone control valveopen, from start-up to compressor shutdown.

Attach the compressor hose to theblow-out adapter ( C ).

Set the pressure-regulating valve onthe compressor to 50 pounds per squareinch (psi). Never exceed 50 psi.

Turn on the compressor. Graduallyincrease the flow of air until all thesprinkler heads pop up. The amount offlow or volume required will depend onthe length of pipe and number of heads.

Do not blow any circuit more than2 minutes at a time. Sustained heatfrom the compressed air may damagepipe and sprinkler drive mechanismsthat use water for lubrication and cooling. Switch to another station orzone by advancing the controller to the

next circuit. Do not turn the controlleroff at any time during this operationunless the compressor is first shut off.

To ensure that lines adequatelydrain, repeat the cycle two or moretimes, activating each zone from thecontroller until nothing more than afine mist appears from the heads.

After blowing out all the zones, leaveone zone on while shutting down thecompressor. You may then unhook thecompressor from the mainline.

Turn the controller to “OFF.”

Blow-out procedure activating sprinkler control valves MANUALLY:

NOTE: Use this option only if your system DOES NOT have electric remote control valves.

Always, if your system does have electricremote control valves, activate thevalves from the controller. Using remotecontrols is safer since you are not closeto irrigation components which can discharge debris during blow-out.

Always wear eye protection and neverstand over irrigation pipes, sprinklers orvalves during this process.

To activate valves manually for the blow-out:

Close main sprinkler shutoff valve ( A ).

Relieve the water pressure on themainline by slowly opening the manualshut-off handle on one of your irrigationzone control valves.

Attach the compressor hose to theblow-out adapter ( C ).

Set the pressure regulating valve onthe compressor to 50 psi. (Never exceedthis setting!)

Manually open the irrigation stationyou want to blow out BEFORE turningon the compressor.

Gradually increase the flow of airfrom the compressor flow valve (notfrom the sprinkler control valve) untilsprinkler heads pop up. The flow or vol-ume required will depend on the lengthof the pipe and the number of heads.

Do not blow any circuit more than 2 minutes at a time. Sustained heatfrom the compressed air may damagepipe and other components. After 2 minutes, turn the compressor off and allow the air to completely purgefrom the compressor tank and sprinkler system.

Turn on the next irrigation controlvalve you wish to winterize before turning off the irrigation control valveyou have just blown out.

Repeat steps until you have blownout each zone at least twice and only afine mist is blowing from each station.

After turning the compressor off,allow any air in the storage tank or irrigation components to dispersebefore approaching the air hose or valves.

Unhook the compressor from theadapter to the sprinkler mainline.

Reminder! Now refer to the Protecting Your Controller in Winter section.

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continued on back flap

A quick coupler located at the start of the mainline is used by many professionals as the blow-out point.

Protecting Your Controller in Winter

After draining the system by the appro-priate method, you need to protect thesystem’s controller to complete the winterization process. Read the follow-ing descriptions to determine whichoption is best for your system.

NOTE: Systems with water pumps requirespecial attention. See item 3 on page 6 if your system uses a water pump.

If your sprinkler system controllerhas a PROGRAMMING DIAL or amechanical ON/OFF switch:

Turn the controller to the “OFF” posi-tion, but leave the controller and back-up battery plugged in. This keeps yourwatering program intact and retainsheat inside the unit, warding off condensation which can harm thecircuit board.

Remember, mechanical models simply “turned off” may be reactivatedby accident. You may want to discon-nect common wires (see below) for further protection.

NOTE: If your system uses a waterpump, you must disconnect the common wire(s) as described in the next section.

If your controller is FULLY DIGITALand has a “keypad” only (such as theEZ-1, CRC or ISC models):

Turn the system to “SYSTEM/OFF”or “AUTO/OFF.” This leaves the programin the memory. A single digit flashingin the display indicates the system is interrupted.

You must now disconnect the com-mon wire(s) that connect the controllerto valves and/or the pump start relay. Apower surge or prolonged power failurecould cause the controller to default tothe automatic mode, sending a signal tothe control valves or pump to come on.

You may decide to unplug the controller and disconnect power before completing this process. THISWILL ERASE PROGRAMS and you willhave to reprogram next spring. If you are unsure, contact an experienced,qualified irrigation contractor.• On indoor models, unplug the

transformer (small black box at the end of the power cord) from the power source. Use gloves to avoid burns from hot transformers!

• On outdoor models, turn off thepower to the controller at themain circuit breaker. DO NOT

attempt to disconnect hardwiresthat run through the conduit direct-ly to your electrical system. This cancause electrical shock and burns.

• Verify that the power is completelyoff by removing the backup bat-tery. Wait for 2 minutes.

Now, disconnect the wire or wiresmarked COMMON, COM, or C on thecontroller terminal strip. (There may betwo terminals marked “common wire.”)Twist a wire nut or place a piece of electrical tape over any loose wire endsto prevent the wire(s) from touchingeach other and causing a short circuit.

NOTE: Many Rain Bird mechanical controllers have a valve wiring harnessthat may simply be unplugged to disconnect the common and stationwires altogether. This is usually a white multi-pin “snap” connector(Molex type) located behind the face panel, inside the cabinet.

If you turned power off, reconnectthe backup battery and turn power back on.

Set the controller to “OFF” and set all stations to zero minutes to preventoperation. In spring, reconnect the

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(Top Left)The start of normal irrigationoperation

(Middle)Air/water mixture as compres-sor forces water out of the heads

(Right)Mostly air out of the head asthe last of the water surges out

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Precisely regulate outlet pressure atthe valve regardless of incoming pres-sure fluctuations with Rain Bird’s newPRS-Dial Pressure Regulating Module.This rugged tool optimizes performanceby automatically maintaining a constant outlet pressure between 15 and 100 psi (1,0 and 6,9 bars) with an accuracy of plus or minus 3 psi (0,1 bar). Improvements in the designallow precise fine-tuning in incrementsas small as 1/2 psi.

Other improvements in spike reductionhelp reduce the potential of damagefrom water hammer and surges. Tooperate properly, the PRS-Dial (PRS-D)should be used in areas where the inlet

pressure is at least 15 psi (1 bar) higherthan the desired outlet pressure.

The PRS-D fits all Rain Bird PGA, ESCB,GB, EFB-CP, BPE and BPES series

valves. A dial cartridge is alsosold separately for retro-fitting existing PRS-B units.

The PRS-Dial’s visible scaleassists with quick, easy

installation. Field installationcan be completed by hand with

an adjustable wrench. The PRS dial isdesigned to simply thread underneaththe solenoid and adapter. A Schradervalve can be ordered separately to connect a pressure hose gauge.

The PRS-D combines an ergonomicdesign with a waterproof cartridge thateliminates fogging, corrosion-resistantglass-filled nylon construction and asnap-tight cover to prevent vandalism.

For more information on this and othernew Rain Bird products, check out theRain Bird Web site at www.rainbird.com.

New PRS-Dial Pressure RegulatingModule Keeps a Consistent Flow

common wires (and reprogram thecontroller if you turned off power during this process).

If your sprinkler system has a water pump, you must disconnect the common wire(s) (See photo B incolumn 2 on page 5). This ensures yoursystem will not default to a runningposition during power surges or powerfailure. Running the pump dry couldseriously damage it. Check with thepump manufacturer’s instructions for further winterization.

If you have a Backflow Preventer,check with the manufacturer for winterization techniques. Leave theshut-off valves open after draining theunit. “Ball”-type shut-off valves shouldbe left at a 45 degree angle to preventwater from entering the seal. Underextreme conditions, insulate the deviceor use heat tape to prevent damage.

Taking the time to winterize all parts of your sprinkler system will not onlyprotect it this winter, but will alsoextend the life of your irrigation components so they can serve yourneeds for years to come!

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Our special thanks to Greg Tepeat Tepe Irrigation for

his assistance with this newsletter. He can be contacted

at sales@TepeServices.comor 513-941-4500.

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