BFMM4001 1-08 MAINTENANCE MANUAL COVERING MODELS: 40-300 Series (1/2”) 4S-100 Series (1/2” ONLY) 40-100 Series (3/4” - 2”) 40-100-T Series (3/4” - 2”) 40-100 Series (2-1/2” - 10”) 40-600 Series (3” - 10”) Conbraco Industries, Inc. P.O. Box 247 Matthews, NC 28106 Phone: (704) 841-6000 Fax 704-841-6020 www.conbraco.
TABLE OF CONTENTS Double Check Valve Backflow Preventer 1/2" - 10" & Double Check Detector Assembly 3" - 10" Section Page Description and Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2, 3 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 Trouble Shooting Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Double Check Backflow Preventer I DESCRIPTION AND OPERATION II INSTALLATION The Double Check Valve (DCV) device consists of two independently acting, spring loaded check valves. Two resilient seated shut-off valves and four test cocks complete the assembly. Each check is designed to maintain a minimum of 1 psi across the valve during normal operation.
(No Flow Condition) FIGURE 4 40 - 10X - T2 Top Entry (No Flow Condition) FIGURE 5 Double Check Detector Assembly (DCDA) The DCDA device consists of a mainline DCV and a by-pass assembly consisting of an approved DCV assembly and water meter. Each device is equipped with test cocks for periodic field testing and is normally supplied with inlet and outlet shut-off valves.
III TROUBLE SHOOTING GUIDE SYMPTOM 1. Check valve fails to hold 1 psid. CAUSE a. Shut-off valve not closed completely. b. Check valve fouled with debris. c. Check poppet stem not moving freely in guide. CORRECTIVE ACTION a. Close #2 shut-off valve or inspect for possible through leakage. b. Inspect and clean seat disc and seat. c. Inspect for debris or deposit on poppet stem or guide. IV MAINTENANCE INSTRUCTIONS 1/2" (40-103) A. Disassembly — Check Valves 1.
V MAINTENANCE INSTRUCTIONS 1/2" (4S-103) Disassembly 1. Close inlet and outlet shut-off valves 2. Bleed pressure from the assembly by opening #2, #3, and #4 test cock. 3. Unscrew and remove bronze cap. 4. Remove stainless steel spacer using lifting tab. 5. Remove first check module by pulling outward with fingers (a small screwdriver may aid removal). Be sure test cock #2 is open so as to prevent hydraulic lock. Generally, the first check o-ring will remain in the bore. 6.
VII MAINTENANCE INSTRUCTIONS 2-1/2" - 10" A. Disassembly — Check Valves 1. Close #2 shut-off valve, then close #1 shut-off valve. 2. Bleed pressure from the assembly by opening #2, #3, and #4 test cock. 3. Remove cover bolts and cover. NOTE: The spring load on the cover will be removed when the cover bolts are backed off approximately 3/8". 4. Remove the complete check assembly straight out of the valve body being careful not to damage the seat ring. 5.
TEST NO. 2: Purpose: To test check valve #2 for tightness against reverse flow. Requirement: The valve shall permit no through leakage in a direction reverse to normal flow under all conditions of a pressure differential. PROCEDURE: Same as test #1 except the “high” side hose is connected to test cock #3 and the “low” side connected to test cock #4. RESTORE OPERATION: Close all test cocks. Remove testing equipment. Open shut-off valves #1 and #2.
DOUBLE CHECK VALVE 8
METHOD 2 NOTE: Test set-up is illustrated in Figure 7 for 1/2" through 2" and Figure 8 for 2-1/2 through 10". EQUIPMENT REQUIRED: Differential pressure gauge type test kit such as Conbraco Model No. 40-200-TKU or 40-200-TK5U. NOTE: For all testing, the gauge and open ends of hoses not being used must be held at the same level as the assembly being tested. TEST NO. 1: Purpose: To determine the static pressure drop across check valve No. 1. Requirement: The static Pressure drop across check valve No.
FIGURE 7 10
FIGURE 8 11
Parts Listing 1/2" (Bronze) 7 8 9 10 2 3 6 5 4 40-300 Series Double Check Backflow Preventer ITEM NO. DESCRIPTION QUANTITY 1 2 3 4 5 6 7 8 9 10 Body Cap Spring Poppet Seat Disc Cap O-Ring Test Cock Union Nut Tail Piece Seal 1 2 2 2 2 2 3 1 1 1 PART NO. 1/2" Consult Factory F-3009-06 A-1750-00 K-3404-00 D-2600-00 D-2501-00 78-257-01 C-1778-06 L-5226-06 D-2607-00 Repair Kits Major Repair Kit (3 (2), 6 (2), part no.
1/2" 4S-103 Double Check Valve ITEM NO. PARTS LIST.
Parts Listing 3/4" - 2" (Bronze) 2 4 5 6 7 3 10 1 11 9 8 14
40-100 Double Check Backflow Preventer ITEM NO. 1 2 n/s 3 4 5 6 7 8 9 10 11 DESCRIPTION QUANTITY Body 1 Cap Plug Spring Poppet Seat Disc Seat Retainer Screw Cap O-Ring Test Cock Check Seat Check O-Ring 2 2 2 2 2 2 2 2 3 2 2 PART NO.
Parts Listing 3/4" - 2" (Bronze) Top Entry 9 4 5 2 6 8 7 3 10 11 1 16
40-100-T SERIES TOP ENTRY DOUBLE CHECK VALVE ASSEMBLY ITEM NO. DESCRIPTION QUANTITY 1 Body 1 2 3 4 5 6 7 8 9 10 11 Cap Spring Poppet Seat Disc Seat Retainer Screw Cap O-Ring Test Cock Check Seat Check O-Ring 2 2 2 2 2 2 2 3 2 2 PART NO.
Parts Listing 2-1/2" - 10" (Ductile Iron) 2 1/2" - 3" - 4" DCV 18
DCV Parts List ITEM NO. 1 1 1 2 3 7 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 DESCRIPTION QUANTITY Shut-Off Valve (OS&Y) Shut-Off Valve (NRS) Shut-Off Valve (Ball) Brass Nipple Test Cock Body C.V. Seat O-Ring C.V. Seat C.V. Stem C.V. Stem O-Ring Retainer Nut Retainer Washer C.V. Seat Disc Seat Disc Holder 1st Check Spring 2nd Check Spring Spring Retainer Jam Nut Cap O-Ring C.V.
6" - 8" - 10" DCV 20
DCV Parts List ITEM NO. 1 1 1 2 3 6A 7 7A 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 N/S *** **** DESCRIPTION QUANTITY Shut-Off Valve (OS&Y) Shut-Off Valve (NRS) Shut-Off Valve (Ball) Brass Nipple Test Cock Stud Body Body C.V. Seat O-Ring C.V. Seat C.V. Stem C.V. Stem O-Ring Retainer Nut/Bolt Retainer Washer C.V. Seat Disc Seat Disc Holder 1st Check Spring 2nd Check Spring Spring Retainer Jam Nut Cap O-Ring C.V.
3" - 4" DCDA Notes: 1. Use P/N W-7062-00 for meter in cubic feet register. Use P/N W-7094-00 for meter in gallons register.
DCDA Parts List ITEM NO. DESCRIPTION 1 2 3 N/S N/S 6 7 8 9 9 10 11 12 13 N/S 15 16 17 18 22 23 24 25 N/S N/S N/S N/S N/S N/S N/S Gate Valve (OS&Y) DCDA Body Test Cock 1st Chk Poppet Ass’y 2nd Chk Poppet Ass’y By-Pass Shut-Off Valve Tee, Reducing Coupling, Water Meter Water Meter in Cubic Feet Water Meter in Gallons 3/4" DCV Elbow, Street By-Pass Shut-Off Valve Swivel Nut Washer, Meter Coupling 3/4" Coupling Nipple, Close Test Cock Cap Cap Bolt Nipple Test Cock Nipple, 3/4" x 3" Lg.
6" - 8” - 10" DCDA Notes: 1. Use P/N W-7062-00 for meter in cubic feet register. Use P/N W-7094-00 for meter in gallons register.
DCDA Parts List ITEM NO. 1 2 3 4 N/S N/S 7 8 9 10 10 11 12 13 14 15 16 20 21 22 23 24 25 N/S N/S DESCRIPTION Gate Valve (OS&Y) Body (1st Check) Body (2nd Check) Ball Valve 1st Chk Poppet Ass’y 2nd Chk Poppet Ass’y By-Pass Shut-Off Valve Tee, 3/4" NPT Coupling, Water Meter Water Meter in Cubic Feet Water Meter in Gallons Coupling, 3/4" 3/4" DCV Elbow, 3/4" NPT By-Pass Shut-Off Valve Nipple, 3/4" NPT Ball Valve Cap Cap Bolt Nipple, 3/4" NPT Nipple, 3/4" x 5-1/2" Lg.
Conbraco Industries Statement of Warranty & Limitation of Liability Conbraco Industries Inc. warrants, to its initial purchaser only, that its products which are delivered to this initial purchaser will be of the kind described in the order or price list and will be free of defects in workmanship or material for a period of two years from the date of delivery to you, our initial purchaser.
SERVICE AND SALES DEPARTMENT P.O. Box 247 • Matthews, NC 28106 Phone: 704-841-6000 • Fax: 704-841-6020 Southeast Region Florida Georgia/Alabama North Carolina/South Carolina/Tennessee-East Virginia/Maryland/Washington, D.C./WV-East sales@blynchandassociates.com dlewis@spotswoodassociates.com sales@promarketinginc.net midsouth7@aol.
