MAINTENANCE MANUAL INDEX DOUBLE CHECK ASSEMBLIES MODELS 850 & 850U 1/2" - 2" FEATURES AND OPERATING PROCEDURES VANDALISM GENERAL SERVICE PROCEDURES CUT-A-WAY DRAWING TROUBLE SHOOTING PROCEDURES CHECK MODULE DISASSEMBLY CHECK MODULE SEAL REPLACEMENT CHECK MODULE RE-ASSEMBLY EXPLODED VIEW PARTS LIST REPAIR KITS TESTING FREEZE PROTECTION OTHER FEBCO MASTERSERIES® PRODUCTS WARRANTY
TABLE OF CONTENTS Features and Operating Procedures ................................................................................................................ 2 Vandalism ......................................................................................................................................................... 2 General Service Procedures ............................................................................................................................ 3 Cut-A-Way Drawing .......
GENERAL SERVICE PROCEDURES 1. FEBCO backflow prevention assemblies can be serviced with standard tools and are designed for ease of maintenance. The assemblies are designed to be serviced in line, so the unit should not need to be removed from the line during servicing. NO special tools are required. Suggested Tool Kit Model 850 (1/2" - 2") • 1 crescent wrench • 1 medium standard screw driver • Differential pressure test kit • 1 medium Phillips screw driver • Box/open end wrench 2.
TROUBLE SHOOTING GUIDE Symptom #1 Cause: Solution: Check fails to hold 1.0 PSID min. A. Debris on sealing surfaces Inspect and clean B. Leaking shut-off valve Inspect and clean, or repair C. Damaged seat or seat disc Disassemble and replace D. Spring stem not moving freely Inspect for debris or damage Symptom #2 Cause: Solution: Chatter during flow conditions. A. Worn or damaged parts Inspect and replace Symptom #3 Cause: Solution: Low flows passing through the mainline valve. A.
SEAL REPLACEMENT CHECK MODULE RE-ASSEMBLY Both check assemblies are disassembled and reassembled in the same manner. To service the checks you may replace the check modules with new ones by using check module assembly kits available from FEBCO. Or, you may also replace the rubber components in the check modules by using the replacement rubber parts kits available from FEBCO. For details on parts and kits please see pages 6 - 8. Use reverse procedure for assembly with the following special instructions.
EXPLODED VIEW CHECK MODULE Page 6 FEBCO Model 850 / 850U (1/2" - 2")
PARTS LIST /4 1 11/4 11/2 2 110134 110031 110032 110136 110027 110025 1 110127 110040 110039 110138 110138 110037 O-Ring 1 39603070 39603070 39603370 39604370 39604370 39604370 2 Cover 1 110041 110041 110035 110026 110026 110026 2.2 O-Ring 1 39622470 39622470 39622970 39624070 39624070 39624070 3 Seat 2 500393 500393 500373 500358 500358 500358 3.
REPAIR KITS How to order parts and Repair Kits 1. Locate item number and kit number in this maintenance manual. 2. Verify the size of the valve the parts are to be used on. 3. Provide full model number located on I.D. plate. 4. Give kit number. 5. A serial number (located on the I.D. plate) will assist in ordering the proper kits. 6. Contact your local FEBCO Parts Distributor. 850 Rubber Parts Kit Part No.
TESTING All mechanical devices should be inspected on a regular basis to ensure they are working correctly. The assembly should be tested at time of initial installation, after servicing or maintenance, and at least annually thereafter.
FEBCO PERFORMANCE, VALUE, AND QUALITY FEBCO MasterSeries® (21/2" - 10") Double Check Assembly Reduced Pressure Assembly Model 876V Model 880V "N" - Shape Model 870V Double Check Detector Assembly Model 876V Model 880V Conventional In-Line Vertical Model 870V Model 850 Model 856 Model 860 For nearly half a century customers have looked to FEBCO for quality products, reliable low headloss performance, and great value.
NOTES FEBCO Model 850 / 850U (1/2" - 2") Page 11
WARRANTY All products manufactured and sold by CMB Industries, Inc. carry with them the following warranty: CMB Industries, Inc. warrants to the original purchaser (who is the end user) all products manufactured by it will be free from defects in workmanship and material for a period of one (1) year from the date of original shipment. CMB Industries, Inc.
