AF & AG 7-96 Dry Pipe Valve - Tyco Fire

Drainage (per NFPA 13)The dry pipe system must bedesigned so that all portions of thepiping system may be drained. Inorder to assure proper drainage:a. If the trapped section is lessthan 5 gallons capacity,provide a 3/4" valve with plugor with nipple and cap.b. If the trapped section isgreater than 5 gallonscapacity, provide a drum drip(2" x 12" pipe nipple with a 1"valve on each end) with theoutlet valve equipped with aplug or nipple and cap.O4" valve 30 feet6" valve 33 feet2. Trapped sections of piping mustbe equipped with auxiliary drainsas follows:InstallationGeneralDry Pipe Valves must be installed in asprinklered area not subject tofreezing conditions, such as a welllighted and heated valve house orsimilar enclosure having sufficientroom to enable ease of installation,care and maintenance.Prior to installing the Dry PipeValve in the piping system, the watersupply line must be thoroughlyflushed to assure that no foreignmatter is present.The valve must be installed in thevertical position in the system piping.Trim according to the Trim AssemblyDiagram on page 6.Remove the hand hole cover andgasket and check the valve clapperfor freedom of movement.In order to place the Dry Pipe Valveinto operation, the valve must be “set”(see Setting Procedure on page 9).The system side of the valve clapperassembly must be primed with waterto the level of the priming connection.TEFriction LossFor use in hydraulic calculations,the pressure loss through the DryPipe Valve may be expressed inequivalent length of schedule 40,C 120 pipe as follows:1. Branch lines, cross and feedmains shall be pitched inaccordance with NFPA 13, Sec.3-6.1.3.LEAir Compressor (continued)The orifice is small enough thatwhen a sprinkler opens, the air supplywill not interfere with the operation ofthe Dry Pipe Valve by rapidly supplying additional air pressure to theupper chamber of the Dry Pipe Valve.The air compressor must beadequately sized to be able to bringthe system air pressure up to thedesign level in 30 minutes or less.The required size of the air compressor in C.F.M., may be determinedfrom the following equation:C.F.M. 0.012 X System Capacity(gallons), where C.F.M. is the free airdelivery in cubic feet per minutebased on standard air at sea level ata system pressure of 25 psig.BS4"6"Note: Priming water is as follows:6" 4 Gallons4" 2 GallonsOThe system piping must besubsequently pressurized with air (ornitrogen) via the air connection. Afterpriming and pressurization of the DryPipe Valve, the main system watercontrol valve must be opened fully.After initial installation, the alarm test,main drain test and trip test(s) mustbe performed and the system resetand placed in service.It is recommended that Central’sAutomatic Air Maintenance Device bepermanently connected to the systemto avoid the possibility of false valvetrips which may result from smallpiping leaks gradually loweringsystem air pressure.If difficulty in performance isexperienced, Central SprinklerCompany should be contacted if anyfield adjustment is to be made.8

Setting ProcedureStep 1. Close the main water supplycontrol valve to the sprinkler system(OS&Y, PIV or other).Step 2. Close all valves in the DryPipe Valve Trim, except the 1/4"three-way valves at the Air PressureGauge and Water Pressure Gauge(Figure 5).Do not force the clapper in attemptingto make the Dry Pipe Valve tight. Donot use grease or other sealingmaterials on the seat rings orrubber seal.Step 9. Reinstall the valve bodyCover and Gasket, being careful totighten the bolts evenly in astaggered fashion.Step 10. Open the Priming SupplyPlug (subassembly Fig. 5, #2) whilemaking sure that the CondensateDrain Valve (subassembly Fig. 5, #2)is closed. Prime the Dry Pipe Valveby slowly pouring water into thePriming Supply. Stop pouring whenwater remains visible in the PrimingSupply Line.Step 4. After all drainage hasstopped, tightly close all auxiliarydrain valves. Leave the inspector’stest valve and system main drainvalve open.Step 11. Open the CondensateDrain Valve to remove excesspriming water from the Dry PipeValve.LENote: Priming water is as follows:6" 4 Gallons4" 2 GallonsOStep 12. Close the CondensateDrain Valve and replace the PrimingSupply Plug.BSStep 5. Remove the valve bodyCover and Gasket (Fig. 1, #8 & #9).Caution: Never attempt to removethe valve cover while the valve isunder pressure.OStep 6. Lift the clapper assembly(Fig. 1, #7) and carefully inspect thewater seat ring (Fig. 1, #2), air seatring (Fig. 1, #3), rubber seal (Fig. 2,#3), and valve body interior. Clean ifnecessary. Do not use cleaningcompounds which could damage therubber seal. Be careful not to scratchor dent the seat rings. Damaged seatrings are not field-replaceable.Step 7. Verify that the clapperassembly moves freely and that thespring-loaded anti-reseat Latch (Fig.2, #7) moves freely under handapplied pressure.Step 8. Raise the rear portion of theanti-reseat Latch so that it clears thetwo cast-in-body latching positions,and lower the clapper assembly tothe closed and fully-seated position.Step 16. Open the Air SupplyControl Valve (subassembly Fig. 5,#4) and admit air to the system. If thesystem is equipped with an automaticAir Maintenance Device, refer to theappropriate Central Bulletin fordetailed instructions.Note: It is good practice to buildup the air pressure on the systemto 10 psi and then individuallyopen the auxiliary drains to forceany remaining water from the lowpoints in the system. When dry airstarts to discharge, close thevalve(s) tightly and replace theplug or cap.TEStep 3. Open the system main drainvalve, the system inspector’s testvalve, and all system auxiliary drainvalves connected to the piping.Replace any sprinklers which mayhave activated.By keeping the inspector’s testconnection open, the system pipingwill be maintained at atmosphericpressure and the test connection willserve as a vent during systemdrainage and during priming of theDry Pipe Valve.Step 15. Clean the Accelerator, if thesystem is so equipped. Refer to theappropriate Central Bulletin fordetailed instructions. Cleaning theaccelerator may proceed concurrentwith establishing the air pressure inthe system.Step 13. Check the Automatic BallDrip Valve (subassembly Fig. 5, #11)for leakage.a. If there is little or no leakage, theclapper is properly seated.Continue with the “SettingProcedure”.b. If there is leakage, the clapper isnot properly seated, and thepriming water is leaking past theair seat into the intermediatechamber. The Dry Pipe Valvemust be re-opened andrepaired. Replace the rubberseal on the clapper if it is worn.After performing the necessaryrepairs, repeat steps 5 through13 above.Step 14. Close the systeminspector’s test valve.9Step 17. Continue to admit air intothe system until the Air PressureGauge (Fig. 5, #5) registers the airpressure required to hold the DryPipe Valve closed against the watersupply pressure. The recommendedair pressure is a function of the watersupply pressure as shown below:Air (psi)Water 5050* When an accelerator is installed with the DryPipe Valve, a minimum air pressure of 25 psiis required.Step 18. Again, check the AutomaticBall Drip Valve for leakage. Thereshould be none.a. If there is no leakage, theclapper is properly seated.Continue with the “SettingProcedure”.b. If there is leakage, the clapperis not properly seated and isnot holding the priming water.

Step 20. Slowly open the main watersupply control valve to the sprinklersystem. When water starts todischarge from the main drain, slowlyclose the main drain valve(subassembly Fig. 5, #1). Then fullyopen the main water supply controlvalve (OS&Y, PIV or other).Step 21. Perform a Main Drain Test(see Main Drain Test Procedure).Acceptance TestingAfter the installation of a Dry PipeSystem is complete and prior to finalacceptance by the Authority HavingJurisdiction, the installer must conducta Main Drain Test, Alarm Test, andTrip Test. The test results must berecorded on the Contractor’s Materialand Test Certificate.Refer to the Trim AssemblyDiagram (Figure 5) which correlateswith the I.D. numbers noted in thefollowing procedures:BSStep 22. Open the Alarm Test Valve(subassembly Fig. 5, #6) and thenperform an Alarm Test (see AlarmTest Procedure).Air TestThe 40 psi air pressure test of thesprinkler system piping must beconducted to verify there are no leaksthat would allow a pressure loss of1.5 psi or more during the 24-hourtest period.Main Drain Test ProcedureThe purpose of the Main Drain Testis to show whether or not the normalwater supply is available to thesystem. By comparing the static andresidual water pressure readings withany previously established readings,a Main Drain Test can indicate thepossible presence of partially closedvalves or other obstructions in thesupply piping. To avoid propertydamage during testing, provision mustbe made for proper disposal of waterissuing from the test outlet.The procedure for conducting amain drain test is as follows:OStep 23. Seal, lock, or otherwisesecure the Alarm Control Valve(subassembly Fig. 5, #7) and themain water supply control valve in theopen position. The system is nowready for service.Step 24. If alarms connect to acentral station or fire department,notify the signal receiving station thatthe system has been placed inservice.TestingGeneralPrior to completion of the installation of a Dry Pipe System, the pipingmust be tested for strength and waterleakage (hydrostatic test) and for airStep 2. Open the main drain valve(subassembly Fig. 5, #1) slowly untilit is wide open. Verify that a fullsteady flow of water is dischargingfrom the main drain pipe. If a fullsteady stream is not discharging,check the main drain piping forobstructions.Step 3. Allow the water to flow untilthe reading on the Water PressureGauge drops and stabilizes. Thenrecord this reading. This is theresidual pressure.Step 4. Close the main drain valveslowly.Step 5. Compare static and residualpressure readings with any previouslyestablished or normal readings. If thereadings compare favorably, thewater supply may be consideredsatisfactory. If the readings vary toany great extent, the condition shouldbe investigated to determine thecause. Some possible causes are:TEStep 19. Activate the air supply tothe Accelerator, if the system is soequipped. Refer to the CentralAccelerator Bulletin for instructions.To prevent a possible false trip of theDry Pipe Valve, perform thisaccelerator activation step prior toopening the main water supplycontrol valve.Hydrostatic TestThe 2-hour, 200 psi hydrostatic testof the sprinkler system piping must beconducted with the valve clapperlatched in the open position. Therubber seal on the face of the clappermay be ruptured if the valve is testedwith the clapper in the closed position.The test should be conducted asweather permits to prevent freezing ofthe piping.LEPriming water must be retained inthe valve before the system can beplaced in service. After correctingany problems, repeat steps 3 thru18.leakage (air test). The test resultsmust be recorded on the Contractor’sMaterial and Test Certificate.OThe Dry Pipe Valve must bere-opened, inspected, andrepaired or replaced.Step 1. While the Dry Pipe Valve is“set”, and the main drain valve isclosed, note and record the readingon the Water Pressure Gauge (Fig. 5,#13). This is the static pressure.10a. Partially or totally closed watersupply control valves.b. Clogged or frozen water supplymains.c. Serious leakage at water supplyvalves or mains.d. Significant modifications to thewater supply system since theprior test. This may be verifiedwith the local water supply utilityor fire department.Alarm Test ProcedureUnlike wet sprinkler systems, it isnot practical to periodically test theoperation of the alarm connected to adry pipe system by opening theinspectors test valve normally locatedat the most remote position of thesystem piping. The reason being thatthe entire dry system piping would fillwith water, hence necessitating timeconsuming system draining and resetting. If alarms connect to a centralstation or fire department, notify thesignal receiving station prior to and atthe completion of the Alarm Test.The procedure for testing the alarmwithout tripping the system is asfollows:

Trip Test ProcedureDry Pipe Valves should be triptested during warm weather,preferably in the summer to allow allcondensation to drain from thesystem piping before the onset ofcold weather.Before proceeding with any trip testof a Dry Pipe Valve, the water supplyline to the system should bethoroughly flushed. The system maindrain may be used for this purpose. Ifthere is a hydrant on the supply line,it should be used to flush the pipingbefore the main drain is opened.Note: If two-way communication isnot available, the time of openingthe inspector’s test valve may bedetermined by observing when theneedle on the Air Pressure Gaugestarts to move downward.Step 5. When the Dry Pipe Valvetrips, quickly note the time and thereading on the Air Pressure Gauge.Step 6. Allow water to flow into thesystem. Note the time when waterstarts to discharge from theinspector’s test connection.BSNote: Assistance is required toperform some of the operations inthis test procedure.Step 4. While observing the AirPressure Gauge, have the inspector’stest valve opened by an assistant andnote the time.The procedure for conducting a fullflow trip test is as follows:OStep 1. While the dry pipe system is“in service”, open the main drainvalve (subassembly Fig. 5, #1) slowlyuntil it is wide open. Then check tomake sure that a full steady flow ofwater is discharging from the maindrain pipe. Allow the water to flow atfull pressure long enough to clear thewater supply pipe of anyaccumulation of scale or foreignmaterial.Step 2. Slowly close the main drainvalve. The Dry Pipe Valve is nowready for Trip Testing.Step 3. Note and record the readingson the Air Pressure Gauge and onthe Water Pressure Gauge.Caution: Before proceeding, beprepared to record the followingperson and organization performingthe test.The organization performing thetest should maintain separate recordswhich show the test results including:initial air and water pressures, triptime, trip air pressure, water deliverytime to the inspector’s test connectionand operating condition of the DryPipe Valve and accessory devices.Note: If there is an Acceleratorattached to the Dry Pipe Valve,initial acceptance testing mustinclude two trip tests, one with andone without the Accelerator inservice.TEStep 3. Open the Alarm Line DrainValve (subassembly Fig. 5, #7) anddrain the water from the alarm line.When drainage is complete, close theAlarm Line Drain Valve.a. Air Pressure reading when theDry Pipe Valve trips.b. The time when the inspector’stest valve is opened.c. The elapsed time, in seconds,when the Dry Pipe Valve trips.d. The elapsed time, in seconds,when water begins flowing fromthe inspector’s test connection.LEStep 2. Close the Alarm Test Valveto silence the sounding device.information; a watch with a sweepsecond hand will be required.OStep 1. Open the Alarm Test Valve(subassembly Fig. 5, #6). This willpressurize the alarm line, cause thepressure alarm switch (if any) toactivate and the water motor alarm (ifany) to sound.Step 7. Keep the Inspector’s TestValve open until clean water isflowing at the connection. Terminatethe test by closing the Inspector’sTest Valve and then the main watersupply control valve (OS&Y, PIV orother).Step 8. Compare the data on trippoint pressure, trip time, and waterdelivery time to the inspector’s testconnection, with previous testrecords. If the data differs to anygreat extent from previous records,the cause should be investigated, andthe condition corrected.Step 9. Drain the Dry Pipe System,thoroughly clean the Dry Pipe Valve,replace parts as required, and resetthe valve (see Setting Procedure).Step 10. The Dry Pipe Valve shouldbe provided with an attached tagwhich shows the date when the valvewas tripped and the name of the11Care &MaintenanceThe Central Model AF and ModelAG Dry Pipe Valves and their accessory devices (air maintenance device,accelerator, pressure alarm switch,water motor alarm), should be semiannually examined by experiencedand qualified personnel, to ensureproper operation and trouble-freeservice.Warning: Any systemmaintenance or inspection thatinvolves placing a control valve“out-of-service” will eliminate thefire protection normally providedby the system.Prior to proceeding, be certain tosecure permission from all AuthoritiesHaving Jurisdiction and notify allpersonnel who may be affectedduring system shutdown. A fire watchduring maintenance periods is arecommended precaution.The owner is responsible for theproper operating condition of all fireprotection devices and accessories.The NFPA Standard 25 entitled,“Inspection, Testing and Maintenanceof Water-Based Fire ProtectionSystems”, contains guidelines andminimum maintenance requirements.Furthermore, the Authority HavingJurisdiction may have additionalregulations and requirements formaintenance, testing and inspectionthat must be obeyed.

Priming Water Level(Refer to Figure 5) Loss of primingwater, either through evaporation intothe system or by seepage past the airseat ring, could result in operation ofthe Dry Pipe Valve. Conversely,accumulation of additional water fromcondensation in the system couldraise the primi

fire sprinkler systems with a maxi-mum working pressure of 175 psi. Manufactured by: Central Sprinkler Company 451 North Cannon Avenue, Lansdale, Pennsylvania 19446 The Central Dry Pipe Valve is a dry pipe sprinkler system water-supply control valve that makes possible the installation of sprinkler systems in buildings subject to freezing .