Zurn-Wilkins 1-375XL Installation Guide
Contents
1. 2 After the device has been pressurized vent all trapped air from both check valves by slightly opening each of the four test cocks 3 Slowly open the downstream shut off valve The Model 375 Reduced Pressure Principle Backflow Preventer is now in service 4 If spitting or intermittent discharges from the relief valve are noted it could be a result of pressure fluctuation and or a water hammer condition in the system If such conditions exist install a ZURN WILKINS water pressure reducing valve a ZURN WILKINS Model 40XL check valve ora ZURN WILKINS Model 1250XL water hammer shock arresters in compliance with industry standards as needed 5 After the Model 375 has been prop erly installed test the device see TEST PROCEDURES If the device fails the test remove the first and second check valves and thoroughly flush the device If the relief valve fails to operate properly inspect the sensing passage for clogging see MAINTENANCE INSTRUCTIONS Clean rubber seals of all debris and place unit back in service ZURN WILKINS www zurn com Testing Procedures MODEL 375 REDUCED PRESSURE PRINCIPLE ASSEMBLY Equipment Required Differential pressure gauge test kit TEST NO 1 Purpose Test 2 check valve for tightness against reverse flow Requirement The valve must close tight against reverse flow under all pressure differentials Procedure 1 Attach the HIGH hose to test cock 2 and th2. 4 13 Relief Valve Discharge Rates Worst case condition If 1st check or relief valve is lodged wide open BACKFLOW PREVENTERS ALL MODELS 375 475 amp 975XL RP amp RPDA FLOW RATE U S GPM Capacity thru Schedule 40 Pipe 7 5 ft sec 10 ft sec 15 ft sec REPAIR KITS FOR 375 s BLOW OUT FLUSH FITTING VESSEL 1 2 3 4 RK34 375BOF 1 2 3 4 RK34 375V 1 RK1 375BOF 1 RK1 375V COMPLETE INTERNALS WEDGE CLAMP 1 2 3 4 RK34 375 1 2 3 4 RK34 375W 1 RK1 375 1 RK1 375W RUBBER PARTS 1 2 3 4 RK34 375R 1 RK1 375R BLOW OUT FLUSH FITTING ZURN WILKINS 1747 Commerce Way Paso Robles CA 93446 Phone 855 663 9876 Fax 805 238 5766 A www zurn com
3. kept above 32 F All the basic installation instructions apply If installation is in a pit or vault the Backflow Preventer must never be submerged in water because this will cause a cross connection Make sure thatthe pit or vault always remains dry by providing ample drainage INDOOR INSTALLATION Indoor installation is preferred in areas that are subject to freezing conditions All the basic installation instructions apply to such installations PARALLEL INSTALLATION Where uninterrupted service from a single meter connection must be maintained two or more Backflow Preventers may be con nected in parallel All the basic installation instructions apply to parallel installation Be sure to allow adequate room between the units for testing and repair PLACING THE DEVICE IN SERVICE After the installation of a Model 375 has been completed place the unit in service as follows 1747 Commerce Way Paso Robles CA 93446 Phone 855 663 9876 Fax 805 238 5766 1 DIRECTION OF FLOW gt 375 REDUCED PRESSURE PRINCIPLE 1 Start with both shut off valves closed Slowly open the inlet shut off valve until the backflow preventer is completely pressur ized Abrief discharge from the relief valve may occur while the device Is pressurizing The discharge should cease by the time the shut off valve is fully open Device should function properly If the discharge does not stop refer to MAINTENANCE INSTRUCTIONS for repair procedures
4. Model 375XL 375XLB 375ST Reduced Pressure Principle Assembly 1 2 3 4 amp 1 This product contains a weighted average lead content less than 0 25 for wetted surfaces Certified to NSF ANSI 61 G LEAD FREE ZURN WILKINS LI Installation U Testing O Maintenance Instructions CAUTION Installation of Backflow Pre venters must be performed by qualified licensed personnel The installer should be sure the proper device has been selected for the particular installation Faulty installation could result in an improperly functioning device ZURN WILKINS Model 375 Reduced Pres sure Principle Backflow Preventers are for use on potable water lines where a health hazard could exist if a backflow situation were to occur Proper performance is dependent upon following these installation instructions and prevailing governmental and industry stan dards and codes Failure to do so according to ZURN WILKINS Limited Warranty releases ZURN WILKINS of any liability that it might otherwise have with respect to that device Such failure could also result in an improperly functioning device Damage to the device could result wherever water hammer and or water thermal expan sion could create excessive line pressure Where this could occur shock arresters and or pressure relief valves should be installed downstream of the device 1 Before installing a Model 375 Backflow Preventer flush the line thor oughly to r
5. N WILKINS parts The ZURN WILKINS Certificate of Limited Warranty provides that failure todo so releases ZURN WILKINS of any liability that it might otherwise have with respect to that device Such failure could also result in an improperly functioning device The Model 375 Reduced Pressure Principle Assemblies should be thoroughly flushed after backflow conditions occur to prevent any type of corrosive deterioration to its components Failure to do so could result in malfunction of the device GENERAL MAINTENANCE 1 Clean all parts thoroughly with water after disassembly ZURN WILKINS 1747 Commerce Way Paso Robles CA 93446 Phone 855 663 9876 Fax 805 238 5766 TEST NO 3 Purpose To test operation of the differential relief valve Requirement The pressure differential relief valve must operate to maintain the ZONE between the two check valves at least 2 PSID less than the supply pressure Procedure 1 Close by pass valve C and open by pass valve A 2 Open by pass valve B very slowly until differential gauge needle starts to drop Hold the valve at this position and observe the gauge reading at the moment the first dis charge is noted from the relief valve Record this as the opening differential pressure of the relief valve 2 TEST COCK 1 TEST COCK 1 SHUT OFF ue la pees VALVE BY PASS BY PASS VALVE A VALVE C BY PASS VALVE B HIGH SIDE HOSE WARRANTY ZURN WILKINS Valves are g
6. T CONNECTION 3 4 NPT BLOW OUT FLUSH FITTING LEAVE BALL VALVES AND TEST COCKS 1 2 OPEN TO PREVENT FREEZE DAMAGE ee te Pr Sime S OUTLET re OFF J NAME HOSE TO AIR FLUSH OUT COMPRESSOR MAIN SHUT OFF VALVE 1 DRAIN DIRECTION OF FLOW gt gt gt BLOW OUT FLUSH OUT CONNECTION 6 PORT 7 Ua BLOW OUT FLUSH FITTING RK34 375BOF RK1 375BOF ADAPTERS AND HOSES PROVIDED BY OTHERS To Blow Out System for freeze protection use the following To Flush System during installation use the following procedure l 2 Turn off main shut off valve 1 that supplies water to the system Open inlet drain valve in the system 2 Open inlet and outlet shut off valves on the backflow preventer 3 amp 5 and all of the test cocks 4 Leave all valves and test cocks in the half open half closed 45 position to allow full drainage of the ball valves and test cocks Remove black backflow preventer housing Replace with orange Blow Out Flush fitting Store backflow preventer housing in a safe location for winter Orange Blow Out Flush fitting may remain in valve body during winter Place plugs in ports to keep debris from entering housing A hose and adapter can be connected to flush out port 7 to drain water to a safe drain Connect an air hose and adapter to the air inlet connection 6 Inject an adequate volume of air to remove all water from the dow
7. check valve seal ring over or replace Continuous discharge of the relief valve signifies a failure of some part of the device To help determine the specific area of failure close the 2 shut off valve If the discharge stops the 2 check requires service If the discharge continues the 1 check requires service 1 CONTINUOUS DISCHARGE 1 Fouled 1 check 2 Fouled relief valve seat 3 Fouled 2 check A Clean check valves and turn check valve seal rings over or replace B Clean relief valve seat and turn relief valve seal ring over or replace In summation the amount of discharge is proportional to degree of fouling Most problems occur in the 1 check which is where debris enters the backflow preventer first Proper performance is dependent upon licensed qualified personnel performing regular periodic testing according to ZURN WILKINS specifications and prevailing governmental amp industry standards and codes and upon following these installation instructions Failure to do so releases ZURN WILKINS of any liability that it might otherwise SPECIFICATIONS Maximum working water pressure Maximum working water temp Hydrostatic End connections 175 PSI 180 F 350 PSI Threaded NPT ANSI B1 20 1 have with respect to that device Such failure could also result in an perly functioning device Blow Out Flush Procedure for Freeze Protection FLUSH OUT PORT 7 HOUSING KE CELS MODEL 375 AIR INLET BLOW OU
8. e LOW hose to test cock 3 2 Close 2 shut off valve 3 Open test cocks 2 and 3 4 Open by pass valves C and A and bleed to atmosphere until all air is expelled 5 Close by pass valve A Open by pass valve B and bleed to atmosphere until all air is expelled Close by pass valves B and C 6 Attach the VENT hose to test cock 4 7 Slowly open by pass valves A and C and keep by pass valve B closed 8 Open test cock 4 9 Indicated pressure differential will drop slightly If pressure differential does not continue to decrease the 2 check valve is considered tight TEST NO 2 Purpose Test 1 check valve for tightness and record pressure drop across 1 check valve Requirement The static pressure drop across 1 check valve shall be greater than the relief valve opening point test 3 and at least 5 0 psid Procedure 1 Close by pass valve A 2 Closetestcock 4 anddisconnect VENT hose from test cock 4 3 Open by pass valves B and C bleeding to atmosphere then close by pass valve B restoring the system to normal static condition 4 Observe the pressure differential gauge and note this as the 1 check valve psid All Model 375 Reduced Pressure Principle Backflow Preventers must be inspected and maintained by licensed personnel at least once a year or more frequently as specified by local codes Replacement of worn or damaged parts must only be made with genuine ZUR
9. e by unscrewing relief valve RV sPRING _ S O RING retaining screw RV SCREW g RV COVER O RING 4 Inspect diaphragm and o ring for damage Replace RV SEAL RNG S Aaa parts To a da coat of grease to RV LOWER PLUNGER _ RV DIAPHRAGM plunger o ring and place on plunger RVUPPERPLUNCER 5 Carefully reassemble cartridge assembly Q 6 Inspect relief valve seat for wear on seating surface BPLUNGER E l CO If damaged replace seat and seat o ring Twist seat O RING aS eal and o ring while inserting to keep it from popping out a P RV COVER BOLTS Troubleshooting When the relief valve discharges intermittently it can be almost always assumed that the device is functioning correctly and that the discharge is caused by systems problem such as inlet pressure fluctuations or water hammer due to quick closing valves PROBLEM POSSIBLE CAUSES CORRECTIVE ACTION 1 SUDDEN OR RAPID SPITTING 1 Drop in inlet pressure A Install an in line spring loaded check valve 2 Sudden increase in downstream upstream of backflow ZURN WILKINS pressure due to water hammer from Model 40XL2 quick closing shut off valve installed B Install pressure reducing valve upstream downstream of backflow unit ZURN WILKINS Model NR3XL C Install in line spring loaded check valve downstream of backflow as close to source as possible but not closer than 4 feet ZURN WILKINS Model 40XL2 2 LIGHT INTERMITTENT DRIP 1 Slightly fouled 1 check A Clean 1 check and turn
10. emove all debris chips and other foreign matter If required a strainer should be placed upstream of the Backflow Preventer CAUTION Do not use a strainer in sel dom used emergency waterlines such as fire lines 2 Provide adequate space around the installed unit so that the test cocks will be accessible for testing and servicing 3 WARNING If installation of a Model 375 is in a building a suitable drain ar rangement MUST be provided to drain off spillage from the relief valve An air gap at least two times the pipe diameter must be provided between the relief valve and the drain piping to prevent a cross connection Air Gap AG 11 not intended to support weight of drain pipe CAUTION Do not pipe the relief valve solidly to a floor drain sewer or sump CAUTION An adequately sized drain is required to prevent possible water dam age due to relief valve discharge ZURN WILKINS PROTECTIVE E gt ENCLOSURE 2 PIPE DRAIN LINE CAN BE ANY STANDARD PIPING MATERIAL OPTIONAL WATER INLET SHUT OFF 4 Install valve at least 12 inches above surrounding flood level 5 Always consult local codes for installa tion methods approvals and guidance OUTDOOR INSTALLATION Model 375 Backflow Preventers may be installed outdoors only if the device is protected against freezing conditions Exposure to freezing conditions will result in improper function or damage to the device The installation location must be
11. it is possible to invert the seal ring This would be considered a temporary solution to fixing a fouled check and should be replaced with a new seal ring as soon as possible 7 Insert cartridge assembly into relief valve cover 8 Check cover o ring in groove on body Clean or replace as necessary 9 Replace relief valve cover and cover screws 10 Place device in service and test per TESTING PROCEDURES MODEL 375 1 2 1 SEAT O RING P 1 CHECK SEAT 7 Inspect seat surface for nicks or dings and replace if necessary POPPET SCREW Use fingernail to check for dings Re grease seat o rings A SEAL RING RETAINER 8 Inspect seat o ring sealing areas in body and wipe clean EKNE POPPET SEAL RING 9 Reverse the above procedures to reinstall check valve l POPPET assembly Drop 2 check assembly in body Then drop 1 check 1 CHECK SPRING assembly in and turn until 1 spring retainer lines up with 2 seat Then push both assemblies into body Care should be taken to make sure the heavy spring is installed in the No 1 check valve Do not overtighten clamp screws as this can cause leak at the sleeve o ring SERVICING RELIEF VALVE eyes n ane 1 Remove relief valve cover screws and cover Gently i Aas pull on diaphragm to remove the cartridge assembly ORNE SFr 2 Inspect seal ring for cuts and embedded debris RV SEAT _ Turn over or replace if required BODY OUTLET 3 Disassemble cartridg
12. nstream portion of the system Do not allow the fitting to overheat Leave drain valve 2 shut off valves 3 amp 5 and test cocks 4 in the half open half closed position 45 for the duration of the winter to prevent freezing Store valve housing check assemblies clamp sleeve and O rings in sealed plastic bag during winter to prevent weathering procedures 1 Install backflow device in pipe system leave water off 2 Remove the black backflow preventer housing from the bronze body 3 Install the orange Blow Out Flush fitting into the bronze body 4 Thread a garden hose adapter into Flush Out port 7 Connect a hose to the adapter and run to a safe drain Shut off valves 3 and 4 should be open 5 Turn on water supply at main shut off valve 1 to flush out any debris in the pipe Turn water off 6 Remove orange Blow Out Flush fitting and replace black check housing back into the line Close shut off valves 3 and 4 Turn water on at main shut off 1 7 Slowly open shut off valve 3 to pressurize backflow preventer Once fully open pressurize system by slowly opening shut off valve 4 CAUTION For freeze protection be certain that main shut off valve 1 remains tightly closed to prevent refilling of the system Also the main shut off valve must be resilient seated to insure no leakage of water into the system Performance Characteristics ZONE PRESSURE U S PSIG ol IS375XL ST 12 1 REV
13. uaranteed against defects of material or workmanship when used for the services recommended If in any recommended service a defect develops due to material or workmanship and the device is returned freight prepaid to ZURN WILKINS within 12 months from date of purchase it will be repaired or replaced free of charge ZURN WILKINS liability shall be limited to our agreement to repair or replace the valve only Maintenance Instructions 2 Carefully inspect rubber seal rings diaphragms and o rings for damage 3 Test unit after reassembly for proper operation see Testing Procedures SERVICING CHECK VALVES 1 Close inlet and outlet shut off valves 2 Open No 2 No 3 and No 4 test cocks to release pressure from valve 3 Unscrew clamp screws and remove clamp inserting screw in center hole can remove stuck clamp Slide sleeve toward inlet pipe Slide valve body toward inlet and lift upward 4 Using finger or blunt object push in outlet end of body both checks should slide out the body inlet A phillips screw driver will work in a 1 2 3 4 valve The closed ball valve handle will work in a 1 valve ZURN WILKINS www zurn com Maintenance Instructions 5 Twist spring retainers counter clockwise to remove from seat and access poppets 6 Inspect the rubber seal ring for cuts or embedded debris To remove seal ring remove screw and seal ring retainer If the reverse side of the seal ring is unused
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