Zurn-Wilkins RK114-975XL Installation Guide
Contents
1. 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 The Model 975XL2 must be installed in a horizontal position to provide proper operation of the relief valve 3 Provide adequate space around the installed unit so that the test cocks will be accessible for testing and servicing 4 If installation of a Model 975XL2 is in a building provide a suitable drain arrange ment 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 PROTECTIVE ENCLOSURE 12 MIN OPTIONAL 30 MAX WATER METER AIR GAP DRAIN N UE WY DIRECTION OF FLOW gt a INLET SHUT OFF CAUTION Do not pipe the relief valve solidly to a floor drain sewer or sump 5 Install valve at least 12 inches above surrounding flood level 6 Always consult local codes for installation methods approvals and guidance OUTDOOR INSTALLATION Model 975XL2 Backflow Preventer may be installed outdoors only if the device is protected against freezing conditions Exposure to freezing conditions will result in improper function or damage to2. trapped air from both check valve by slightly opening each of the four test cocks 3 Slowly open the downstream shut off valve The Model 975XL2 Reduced Pres sure 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 water pres sure reducing valves or water hammer shock arresters in compliance with industry standards as needed 5 After the Model 975XL2 has been pro perly 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 Proposition 65 Warning This product contains chemicals known to the State of California to cause cancer or birth defects or other reproductive harm ZURN WILKINS 1 Testing Procedures MODEL 975XL2 REDUCED PRESSURE PRINCIPLE ASSEMBLY Equipment Required Differential pressure gauge test kit 975XL2 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 Procedur
3. 876 Fax 805 238 5766 4 ISSM975XL2 REV 4 13 www zurn com
4. Model 975XL2 LEAD FREE Reduced Pressure Principle Assembly 1 4 2 This product contains a weighted average lead content less than 0 25 for wetted surfaces Certified to NSF ANSI 61 G ZURN WILKINS Installation U Testing Q 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 se lected for the particular installation Faulty installation could result in an improperly functioning device ZURN WILKINS Model 975XL2 Reduced Pressure 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 accord ing 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 975XL2 Back flow Preventer flush the line thoroughly to remove all debris
5. at the discharge is caused by systems such as inlet pressure fluctuations or water hammer due to quick closing valves PROBLEM 1 SUDDEN OR RAPID SPITTING 2 LIGHT INTERMITTENT DRIP POSSIBLE CAUSES 1 Drop in inlet pressure 2 Sudden increase in downstream pressure due to water hammer from quick closing shut off valve installed downstream 1 Slightly fouled 1 check CORRECTIVE ACTION A Install an in line spring loaded check valve upstream of backflow B Install pressure reducing valve upstream of backflow unit C Install in line spring loaded check valve downstream of backflow as close to source as possible but not closer that 4 feet A Clean 1 check and turn 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 ZURN WILKINS 1747 Commer
6. ce Way Paso Robles CA 93446 Phone 855 663 9876 Fax 805 238 5766 3 ZURN WILKINS www zurn com Performance Characteristics SPECIFICATIONS Maximum working water pressure 175 PSI a End connections Threaded NPT 38 3 4 6 9 Com e a o FLOW CHARACTERISTICS MODEL 975XL2 1 4 3 8 amp 1 2 STANDARD amp METRIC FLOW RATES l s L 0 0 57 0 76 0 95 N PRESSURE LOSS PSIG a k PRESSURE LOSS kpa FLOW RATES GPM Rated Flow Established by approval agencies MODEL 975XL2 3 4 1 1 1 4 1 1 2 amp 2 STANDARD amp METRIC FLOW RATES l s 1 26 2 52 3 8 5 0 a 12 Ls 158 20 2 B N g 15 2 rd ag gt 10 5 l i E fd a 5 2 FLOW RATES an Rated Flow Established by approval agencies 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 in structions Failure to do 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 ZURN ZURN WILKINS WILKINS 1747 Commerce Way Paso Robles CA 93446 Phone 855 663 9
7. e 1 Attach the HIGH hose to test cock 2 and the 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 3 TEST COCK 4 TEST COCK BY PASS VALVE A HIGH SIDE HOSE ZURN WILKINS 2 1747 Commerce Way Paso Robles CA 93446 Phone 855 663 9876 Fax 805 238 5766 975XL2 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 1 and at least 5 0 psid Procedure 1 Close by pass valve A 2 Close test cock 4 and disconnect 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 975XL2 TEST NO 3 Purpo
8. l check valve as sembly Care should be taken to make sure the heavy spring is installed in the No 1 check valve For the 3 4 1 975XL2SE the No 2 poppet has a cupped seal retainer For the 1 1 4 2 975XL2SE the No 1 seat has a taller seat profile than the No 2 seat SERVICING RELIEF VALVE 1 Remove relief valve cover bolts and cover Gently pull on dia phragm to remove the cartridge assembly 2 Inspect seal ring for cuts and embedded debris Turn over or replace if required 3 Disassemble cartridge by unscrewing relief valve retaining screw 4 Inspect diaphragm and o rings for damage Replace required parts and apply a light coat of grease to plunger o ring 5 Carefully reassemble cartridge assembly 6 Inspect relief valve seat for wear on seating surface If dam aged replace seat and seat o ring 7 Insert cartridge assembly into relief valve body 8 Replace relief valve cover and cover bolts 9 Place device in service and test per TESTING PROCEDURES For seat removal assistance consult factory 1 SEAT RELIEF VALVE PLUNGER UPPER RELIEF VALNE 0 0 Y FERA ay gt amp ee Dof ER a RELIEF VALVE COVER COVER BOLTS heme SCREW RELIEF VALVE RING RETAINER RELIEF VALVE J LOWER SEAT O RING O RING PLUNGER RELIEF VALVE Troubleshooting When the relief valve discharges intermittently it can be almost always assumed that the device is functioning correctly and th
9. revent 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 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 check valve covers using appropriate size wrench CAUTION Cover is spring loaded To avoid injury hold cover down firmly with one hand while unscrewing 4 Remove check valve cover spring and poppet assembly RETAINING SCREW CHECI SEAL RING RETAINER CHECK COVER CHECK SERINE CHES TE y AAAA AAAA POPPET onno COVER L SEAL RING CHECK 5 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 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 6 Inspect valve cavity and seating area Remove any debris 7 lf installed with removable seat unscrew seat from body and replace with new seat and lightly grease o ring 8 Reverse the above procedures to reinstal
10. se 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 discharge is noted from the relief valve Record this as the opening differential pressure of the relief valve 1 CHECK VALVE 2 TEST COCK 1 TEST COCK 1 SHUT OFF VALVE BY PASS VALVE C BY PASS VALVE B i VENT HOSE LOW SIDE HOSE ZURN WILKINS www zurn com Maintenance Instructions All Model 975XL2 Reduced Pressure Principle Backflow Preven ters 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 ZURN WILKINS parts The ZURN WILKINS Certificate of Limited Warranty provides that failure to do so releases ZURN WILKINS of any liability that it might otherwise have with respect to that device Such failure could also result in an im properly functioning device The Model 975XL2 Reduced Pressure Principle Assemblies should be thoroughly flushed after backflow conditions occur to p
11. the device The installation location must be 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 could cause a cross connection Make sure that the 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 975XL2 has been completed place the unit in service as follows 975XL2 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 A brief 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 INSTRUC TIONS for repair procedures 2 After the device has been pressurized vent all
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