Febco 805YD, 806YD Operation And Maintenance Manual

FEBCO Operation and Maintenance

805YD / 806YD

Double Check and Double Check Detector Assembly

(21/2" – 10")

805YD

806YD

(Shown with OS&Y Shut-offs)

FEATURES AND OPERATING PROCEDURES

This device consists of two independently operating poppet type check valves. Each check valve is spring loaded to maintain a minimum
of 1 PSIG differential pressure across the check in a no-flow condition. In a normal flow condition the checks open an amount correspond­ing to the flow rate. During a backflow (backpressure) situation the seat discs close and seal to prevent any flow reversal. Sizes 2
through 10" (805YD) include two spring loaded Y-pattern check valves with epoxy coated ductile iron bodies and bronze trim, two cast iron
shut-off valves and four testcocks for field testing. All valves are flanged type and the unit is shipped completely assembled.

The Model 806YD device consists of a mainline double check valve with a metered
the mainline checks. The mainline pressure drop is slightly higher than the by-pass, thus all small flow up to the crossover po int (approx.
9 GPM) is through the by-pass. Above the crossover point flow is through the mainline and the by-pass.

The FEBCO 806YD Device main line unit consists of two independent, spring loaded, Y-pattern check valves, two shutoff valves
and four testcocks. The spring loaded poppets in conjunction with soft elastomer discs provide drip tight closure against backflow. The
Y-pattern valve design provides low pressure loss at the high flow rates . The shutoff valves are OS&Y type, UL listed f or fireline service.

The by-pass line assembly consists of a water meter in series with a Model 805YB
with accurate registration between 1 and 20 gpm flow rates. The static pressure drop across both checks is approximately 2 PSI less
than the mainline check valves.

Consult local codes before installing any Backflow Prevention assembly.

3

/4" by-pass double check valve connected around

3

/4" double check valve. The meter is the total type

1

/2"

GENERAL SERVICE PROCEDURES (General service instructions applicable to all sizes.)

1. Rinse all parts with clean water prior to assembly.

2. DO NOT USE ANY PIPE DOPE, OIL, GREASE OR SOLVENT ON ANY PARTS unless instructed to do so.

4. Do not force parts. Parts should fit freely together. Excess force may cause damage and render the device inoperable.

5. Carefully inspect seals, seating surfaces, etc. for damage or debris.

5. Test unit after ser vicing to insure proper operations.

6. Refer to applicable parts list and figures for more information.

7. A table on the back page provides size and material information for standard parts (non-special design). These parts can usually be
purchased locally from parts distr ibutors, rather than special order from the factory.

8. Some water conditions can cause a buildup of calcium or similar material deposits on some moving parts. Normally this condition
would not occur on devices used in systems with varying flow rates. The scraping action of mo ving parts helps to remove any deposits.
However, with devices used on static systems such as firelines, any deposits would not be scraped away and could interfere with the
check valve operation. Devices in these applications should be disassembled and inspected on a periodic basis depending on water
quality. Any deposits should be removed from the center guiding stem and bushings. Use care to avoid damage to guiding surfaces.

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. Acceptable test procedures are published by
Foundation for Cross Connection Control and Hydraulic Research at the University of Southern California (USC), The American Water
Works Association (AWWA), The American Society of Sanitary Engineer ing (ASSE Series 5000) and the Canadian Standards Associa­tion (CAN/CSA B64•10). Please consult the regulatory authority in your area for more specific information.

FEBCO Model 805YD & 806YD (21/2" - 10") Page 1

TROUBLE SHOOTING GUIDE

Symptom #1

Cause:

Solution:

Check fails to hold 1.0 PSID min.

Symptom #2

Chatter during flow conditions.

Symptom #3

Low flows passing through the
mainline valve (806YD only).

A. Debris on sealing surfaces
B. Leaking shut-off valve
C. Damaged seat disc or seat ring
D. Damaged guide holding check open

E. Weak or broken spring

Cause:

A. Worn or damaged guide

Cause:

A. Mainline check fouled
B. Meter strainer plugged
C. Damaged mainline seat disc or seat
D. Broken mainline spring

Disassemble and clean
Disassemble and clean or repair
Disassemble and replace
Disassemble and replace guide pin

and/or sleeve bushing
Disassemble and replace spring

Solution:

Disassemble & repair or replace guide

Solution:

Disassemble and clean
Disassemble and clean
Disassemble and replace
Disassemble and replace

HOW TO ORDER 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 for.

3. Provide full model number located on I.D. plate.

4. Record 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.

REPAIR KITS

805YD/806YD Assemblies/Kits

Description 21/2"3"4"6"8"10"

Model 805YD Spring Assembly

(Items: 3. 4.1, 5, 6, 7, 7.1, 7.2, 9, 11, 15, 50) 905-086 905-088 905-467 902-469 902-471 902-473

Model 805YD/806YD Rubber Parts

(Items: 11, 14, 50) 905-059 905-060 905-061 905062 905-063 905-064

Model 805YD/806YD Seat Kit

(Items: 2, 2.1, 2.2, 12) 902-386YD 902-385YD 902-384YD 902-383YD 902-382YD 902-381YD

Model 805YD/806YD Lg. Mounting Kit

(Items: 16, 17, 17.1; Both Ends) 905-036 905-037 905-038 905-039 905-040 905-041

Model 805YD/806YD Cover Assembly

(Items: 4, 4.1, 14, Aircock (not shown) 902-497 902-498 902-499 902-500 902-501 902-502

Model 806YD Spring Assembly

(Items: 3, 4.1, 5, 6, 7, 7.1, 7.2, 9, 11, 15, 50) - - 902-514 902-515 902-516 902-517

Model 806YD By-Pass Kit (without meter)

(Items: 301 through 313) - 905-138 905-138 905-138 905-138 905-138

Page 2 FEBCO Model 805YD & 806YD (21/2" - 10")

41.1

MODEL 805YD / 806YD

Cut-a-Way

13

4

10.4

2.4

2.3

11

14

4.1

9

5

3

7.2

17.4

7.1

MODEL 806YD

By-Pass Assembly

40

41 42

16

305.1

17

17.1

2.17 615

12.1

2 150

Vertical Pipe

305.1

306

305.1

312

313
309

308
300

303

304

311

302

308
309

307.1

301.1
311

311

MODEL 805YD/806YD PARTS

Fig No. Description (QTY)

1 Body (1)
2 Seat Ring (1)

2.1 Bushing (1)

2.3 Washer (6)

2.4 Capscrew (6)
3 Guide (2)
4 Cover (4)

4.1 Bushing (2)
5 Disc Holder (2)
6 Disc Washer (2)
7 Stem (2)

7.1 Screw (2)

7.2 Washer (2)
9 Spring (2)

Fig No. Description (QTY)

12.1 O-Ring (2)
13 Capscrew (16)
14 O-Ring (2)
15 Hex Nut (2)
16 Gasket (1)
17 Capscrew (4)

17.1 Hex Nut (12)

17.4 Lift Strap (2)
40 Ball Valve (3)
41 Nipple (1)

41.1 Nipple (2)
50 O-Ring (2)
42 NRS Gate Valve
42 OS&Y Gate Valve

11 Seat Disc (2)

FEBCO Model 805YD & 806YD (21/2" - 10") Page 3

Fig No. Description (QTY)

300** Meter
301** Nipple
302** Ball Valve
303** Ball Valve

301.1** Testcock
304** Elbow
305** Nipple
306** Nipple

307.1** Tailpiece
308** Coupling Nut
309** Meter Washer
311** Nipple
312** 805Y (Less Shutoff's)
313** Coupling

** Used in the Model 806YD only.

MODEL 805YD/806YD COMMERICAL PARTS

Item Description Material 21/2"3"4"6"8"10"

7.1 Screw Brass - ­12 O-Ring Buna-N 568-238 568-246 568-254 568-264 568-273

31/

13 Cap Screw SS

7

14 O-Ring Buna-N 568-244 568-252 568-263 568-272 568-451

41/

15 Lock-Nut Brass

/

16

x

33/

2

-14

x

41/

4

3

/8 -24

1

x

/

4

8

x

1

1

x

/

2

8

41/

7

51/

/

16

x

43/

2

-14

x

51/

4

3

/8 -24

4

x

2

3

/8-16 x 11/

1

x

/

51/

8

1

1

/2 -13

1

x

/

71/

8

x

53/

2

x

71/

4

3

/4 -16

1

x

4

x

11/

1

x

2

3

/8-16 x 2

2

1

x

/

71/

8

5

4

/

91/

8

2

/8 -11

x

2

3

/4 -16

73/

93/

x

4

x

11/

1

x

4

3

/8-16 x 2

1

/

8

2

/

8

x10x

91/

2

3

/4 -10

11x111/

7

/8 -14

x

11/

x

2

/8105/

3

2

1

/4123/

3

/8-16 x 2

x

109/

16

/4 -10

x13x

4

7

/8 -14

1

x

/

16

8

x

13/

4

1

/

8

Elastic Elastic Elastic Elastic Elastic Elastic
17 Bolt & Nut Steel
40 Ball Valve Brass
51 O-Ring Buna-N 568-014 568-014 568-116 568-116 568-118 568-118

5

/8 -11 x 21/

1

/2 IPS 200#1/2 IPS 200#1/2 IPS 200#3/4 IPS 200#3/4 IPS 200#3/4 IPS 200#

1

5

1

x

x

/

/

2

8

41** Nipple Bronze - ­62** 90o Elbow Bronze - ­63** Tee Bronze - ­64** Nipple Bronze - ­65** Bushing Bronze - ­66** Nipple Bronze - - -

5

/8 -11 x 21/

4

1

5

1

x

/

16

x

/

/

2

8

5

/8 -11 x 23/

2

3

15

1

x

/

16

x

/

/

4

16

1

x

/

Close

2

1

/

2

1

1

1

x

x

/

/

2

2

1

x

/

5

2

1

3

x

/

2

/

4 ---

3

/4 -10 x 3

4

3

15

x

/

4

3

3

/

4

/

4

3

/

x

Close

1

3

x

3

x

/

4

x

/

4

/
/

16

2

4

21/

x

x

6

/

16

/

2

3

/4 -10 x 31/

1

7

x

/

16

3

/

4

2

x

/

11/

8

16

3

x

/

Close

4

1

/

2

3

3

3

x

x

/

/

4

4

3

x

/

6

4

3

x

/

21/

4

2

7

/8 -9 x 31/

4

3

7

/

/

32

8
3

/

/

4

x

x

4

3

3

/

11/

16

Close

3

/

4

-

x

/

4

x

21/

4

2

3

x

/

32

6

2

** Used in the Model 806YD only.
These parts are commercially available through most hardware distributors or retailers. Shut-off valves, testcocks, flange gaskets,
etc., are also commercially available but not listed. The water meter is a

5

3

x

/

/4 size. Several brands are USC approved for use on

8

the Model 806YD. Contact the factory for additional information.

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. also warrants that all internal components of
will be free from defects in workmanship and material for a period of five (5) years from the date of original shipment and also that the
body only of the

1

/

2" through 1

1

/

4" Model 765 will be subject to a lifetime warranty against damage by freezing.

1

/

2" through 2" Model 850/860 and

1

/

2" through 1" Model 766 products,

This warranty is applicable provided such products are used under normal conditions within the recognized pressure, flow and
temperature limits and are given normal service and care. CMB INDUSTRIES, INC. MAKES NO OTHER REPRESENTATION OR
WARRANTY OF ANY KIND, EXPRESSED OR IMPLIED, IN FACT OR IN LAW, AND EXPRESSL Y DISCLAIMS ALL O THER WARRAN­TIES, INCLUDING WITHOUT LIMITATION, THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR PARTICULAR PURPOSE.
In the event of a defect in mater ial or workmanship of a product covered by this warranty, CMB Industries, Inc. shall, at its sole option,
repair or replace such defective product. CMB Industries, Inc. shall not be liable for any labor required to repair or replace any product
covered by this warranty. This warranty is void with respect to any such product which is altered or tampered with by anyone
without prior consent of CMB Industries, Inc. CMB Industries, Inc. shall not be liable under any circumstances for damages caused by
accident, misuse or abuse of the product or for failure to follow the installation, maintenance or operating instructions. IN NO EVENT
SHALL CMB INDUSTRIES BE LIABLE FOR CONSEQUENTIAL, INCIDENTAL, INDIRECT, PERSONAL INJURY, PROPERTY OR
PUNITIVE DAMAGES.

To make a claim under this warranty, the buyer must notify the factory in writing within ten (10) days of discov ery of any claimed def ects
or workmanship, and if authorized by the factory, shall retur n the product in the same condition as when received by the buye r,
transportation prepaid, to the factory or to such other location as directed by the factory. If said returned product is found by the factory
to be defective in workmanship or materials, it shall be repaired or replaced without charge, pursuant to the terms of this warranty. This
warranty excludes component parts or appurtenances not manufactured by CMB Industries, Inc. Any claims with respect to such
equipment must be made to the manufacturer thereof in accordance with the terms of the warranty, if any, given by such manufacturer,
or pursuant to such warranties as may exist by law. The physical or chemical properties of CMB Industries, Inc. products represent
typical, average values obtained in accordance with test methods and are subject to normal manufacturing variations. This information
is supplied as a technical service and is subject to change without notice.

FEBCO Backflow Prevention

P.O. Box 8070 • Fresno, CA 93747-8070
559 252-0791 • Fax: [phone] •

mm805lg 2/02 Copyright 2002 SPX Valves & Controls

www.FEBCOonline.com

FEBCO is a product of

ISO 9001 CertifiedISO 9001 Certified

ISO 9001 Certified

ISO 9001 CertifiedISO 9001 Certified

SERVICE PROCEDURES FOR MODELS 805YD (2

1

/2"– 3)

1. Disassembly-Check Valves

a. Close inlet and outlet shut-off valves. Bleed residual

pressure by opening

#

2, #3 and #4 testcocks.

b. Remove cover bolts unif ormly while holding cover in place.

Remove cover. CAUTION: Spr ing is retained in body

by cover.
c. Lift spr ing and check assembly from body.
d. Unscrew bushing (Item 4.1) from cover.

2. Check Assembly Repair

a. Unscrew nut on stem and remove disc washer and

seat disc.

3. Valve Seat Removal

a. Remove seat ring by unscrewing in counterclockwise

direction.
b. Remove bushing and bushing nut.
c. Remove O-Ring.

SERVICE PROCEDURES FOR MODELS 805YD (4" -10")

1. Disassembly-Check Valves

a. Close inlet and outlet shut-off valves. Bleed residual

pressure by opening

#

2, #3 and #4 testcocks.

b. Remove cover bolts and cover. Unscrew bolts uniformly

to avoid binding of the cover. The spring will push the

cover approximately

1

/2" off the top of the valve body.

2. Check Assembly Repair

a. Leave check assembly in body.
b. Install long studs in body 180

o

apart. See Spring Removal

Tool on page 5.
c. Place spring removal tool over stud and retain with

nuts. See Spring Removal Tool on page 5.

CAUTION: To a void possible injury, do not attempt to

remove spring tension without the use of this tool.

NOTE: Newer devices have the disc holder threaded

on the stem. Therefore, the seat disc can be removed

without releasing spring tension. Threaded disc

holders have four (4) cast lugs, (6 lugs on 10 devices),

1

/

2" high located on back side, outside the spring

diameter. If the device being serviced does not

have these lugs, spring tension must be released

before further disassembly.

4. Assembly - Check Valve

a. Use reverse procedure for assembly.
b. NOTE: On older valves the disc holder is sealed

to the stem with permatex. If seal is broken, the
stem and holder must be cleaned and new sealant ap­plied. Newer valves use an O-Ring and permatex is not
required.

c. Do not apply any grease or oil on the rubber

seat disc.
d. Do not damage epoxy coating.
e. Test unit to insure proper operation.

d. Unscrew capscrew (7.1) using

9

/16" hex socket.

e. Release spring tension by unscrewing nuts on long studs.

Use alternating turns to keep tool parallel to valve body.
f. Remove spring guide and stem assembly.
g. Remove seat disc by unscrewing nut on stem.
h. Remove guide bushing by unscrewing.

3. Valve Seat Removal

a. Disassemble check valve .
b. Remove seat disc ring by unscrewing in counterclock-

wise direction. See Seat Removal Tool on page 5 for the

design of a tool that will simplify this process.
c. Remove bushing and bushing nut.
c. Remove O-ring.

4. Assembly - Check Valve

a. Use reverse procedure for assembly.
b. Do not damage epoxy coating.
c. Test unit to insure proper operation.

SERVICE PROCEDURES FOR MODELS 806YD

This device is serviced using the same procedures as the Model 805Y with the following exceptions:

a. Mainline springs are retained on the disc holder with a clamp.
b. For bypass Model 805YB service and repair consult maintenance manual 980116/mm805sm for more information.
b. The meter is removed by loosening the two union nuts. For specific meter service information contact the manufacturer

or their representative directly.
c. Remove and clean in-line strainer mounted in the meter inlet port.
d. Test unit after reassemble to insure proper operation.

FEBCO Model 805YD & 806YD (21/2" - 10") Page 4

"C" DIA
2PL'S

SPRING REMOVAL TOOL

1" DIA

"B""B"

"A"

"D" TREAD
THREADED ROD (STEEL)

1/2" STEEL PLATE (MIN)

2 1/4" (MIN)

NOTE: This information is provided to
expedite servicing of FEBCO products.
One tool may be fabricated for use on
all required sizes by drilling all holes at
appropriate dimensions in a single steel
plate of maximum required length.

CAUTION: To avoid possible injur y
during use, do not fabricate tool from
lesser strength material or to smaller
dimensions than minimums shown.

"B"

"D"

"E"

SEAT RING T OOL

"E" DIA THRU

SPRING REMOVAL TOOL DIMENSIONS

Size A B C D E

4" 91/
6" 121/
8" 141/

10" 161/

2

2

4

2

41/
55/
63/
71/

4

8

8

2

5

/

8

3

/

4

7

/

8

7

/

8

1

/

13 51/

2 –

5

/

11 51/

8 –

3

/

10 7

4 –

3

/

10 7

4 –

2

2

"A" STD WT. PIPE (STEEL)

SEAT RING T OOL DIMENSIONS

Size A B C D E

1

/

2

8

"C" MILLED NOTCH

"C" X "C" SQ - 120º APART

3 PLACES

21/2"2

3" 3 8
4" 4 9
6" 6 10
8" 8 12

10" 10 15

Page 5 FEBCO Model 805YD & 806YD (21/2" - 10")

1

/

2

1

/

5 11

1

/

2

5

/

8 11

5

/

8

5

/

8 11

11

11

11