background image

Size 

A

C

D

E (Dia.)

F

in

Pipe Size (in)

Min. Length (in)

in

in

in

in

1

 

1/4

1

3.12

0.38

0.25

0.44

0.55

1

 

1/2

1

3.12

0.38

0.25

0.44

0.50

1

 

1/4

3.38

0.38

0.25

0.44

0.50

2

 

1/2

2

4.0

0.38

0.38

0.56

0.62

2

 

1/2

4.5

0.50

0.38

0.56

0.62

3

5.0

0.50

0.44

0.56

0.62

6.50

0.62

0.44

0.56

0.62

6.  After removing the Stem Nut, the remainder of the Disc & Diaphragm Assembly should disassemble easily. Polish stem guide  

surfaces with fine emery cloth to remove any mineral deposits and inspect for excessive wear. Remove any mineral build-up from 

other components with wire brush or by using a Mineral Dissolving Solution. Inspect parts for wear and replace if necessary.

7.  Inspect valve seat. If seat is not damaged, removal is not necessary. Valve seats 6" and smaller are threaded into the body of the 

valve and require a seat removal tool (Figure 5) (Table 1 details the tool dimensions for seat removal). Valve seats 8" and larger are 

held in the valve body with stainless steel cap screws. Remove seat retaining screws and lift seat straight up (Figure 6).

Figure 6

*Schedule 40 steel pipe

Figure 5

Valve Body

Valve Seat

All-Thread

Nut and Washer

2PLCS

Angle or 

Channel Iron

120

B (Min)          

E  Dia. 4 Holes

    

 

90  Apart        

D         

TYP <3 PLCS>

    

 

120  Apart  

C TYP <3 PLCS>      

F       

A         

Table 1: Seat Removal Tool Dimension

IOM-ACV-115-74_6115-74   2115 

EDP# 1917043 

© 2021 Watts         9

Summary of Contents for LFM115-74

Page 1: ...he Pressure Reducing Control 3 Maintenance Schedule 6 Trouble Shooting Guide 6 Valve Disassembly Instructions 8 ACV Schematic 11 Local building or plumbing codes may require modifica tions to the information provided You are required to consult the local building and plumbing codes prior to installation If the information provided here is not consistent with local building or plumbing codes the lo...

Page 2: ... in a controlled manner to protect the system from damaging over pressure 1 Prior to installation flush line to remove debris 2 Install valve so the flow arrow matches flow through the line and gauges to monitor valve inlet and outlet pressures A Position Indicator can be installed to provide visual indication of valve position and operation without disassembly 3 Install isolation valves upstream ...

Page 3: ...26 28 30 34 40 STEP 2 To ensure proper operation any trapped air will need to be bled off the valve cover during startup If your ACV includes a bleed valve use a flat head screwdriver to slowly open the valve See Figure 1 If your valve does not include a bleed valve bleed air by loosen ing a fitting on the valve or a plug at the highest point of the valve assembly STEP 3 Pressure the line by openi...

Page 4: ...terclockwise increasing the rate of opening IF recovery of downstream pressure is too quick as indicated in a rapid increase in pressure possibly higher than the desired set point turn the adjustment screw IN clockwise decreasing the rate of opening See Figure 3 STEP 4 If equipped with closing speed Closing Speed Needle Valve Adjustment The closing speed needle valve regulates fluid pressure into ...

Page 5: ...While the LFM115 74 is controlling pressure with the Main Valve Pressure Reducing Control start adjusting the Low Flow By Pass by adjusting IN until you see the downstream pressure rise on the gauge Continue adjusting to the specified set point See Figure 4 Counterclockwise to DECREASE downstream pressure Figure 4 223 Low Flow By Pass Control Setting the Low Flow By Pass Control IOM ACV 115 74_611...

Page 6: ... specification sheets for approximate cover capacity A continuous flow of water from the open port indicates a damaged diaphragm or loose disc diaphragm assembly Disassemble valve and replace diaphragm or tighten disc diaphragm assembly Test 2 Seat Seal Test 1 Close downstream isolation valve and install pressure gauges on an open inlet and outlet port of main valve 2 Open upstream isolation valve...

Page 7: ...bly by partially opening from full closed position Improperly configured opening speed control if equipped Adjust opening speed control to verify functionality adjust as required Standard setting for opening speed control is 11 2 21 2 turns open from full closed position Can be adjusted in field Main Valve will not close Closed isolation valves in pilot system Check isolation valves ensure open Di...

Page 8: ...Remove cover nuts and washers 3 Remove the cover If cover is not free to be removed loosen it by tapping upward along its outside edge with a dull cold chisel pic tured above a Large valves may require the installation of lifting eye bolts in order to facilitate cover removal installation ports are provided on the cover for this purpose 4 Remove the Disc and Diaphragm Assembly from the valve body ...

Page 9: ...brush or by using a Mineral Dissolving Solution Inspect parts for wear and replace if necessary 7 Inspect valve seat If seat is not damaged removal is not necessary Valve seats 6 and smaller are threaded into the body of the valve and require a seat removal tool Figure 5 Table 1 details the tool dimensions for seat removal Valve seats 8 and larger are held in the valve body with stainless steel ca...

Page 10: ...Nuts in a crossing pattern to ensure even distribution Test the Disc and Diaphragm Assembly for smooth travel by following the Freedom of Movement Test procedure in previous section 11 Test the integrity of the Seat Seal by following the Seat Seal Test procedure in previous section 12 Return valve to service by following instructions on the Technical Bulletin matching the valve function Size in 11...

Page 11: ...eel 9 Stem Washer ASTM A276 304 Stainless Steel 10 Diaphragm Washer ASTM A536 65 45 12 Epoxy Coated Ductile Iron 11 Diaphragm Buna N Nitrile 12 Disc Retainer ASTM A536 65 45 12 Epoxy Coated Ductile Iron 13 Seat Disc Buna N Nitrile 14 Spacer Washer x5 NY300 Fiber 15 Disc Guide ASTM A743 CF8M 316 Stainless Steel 16 Shaft ASTM A276 304 Stainless Steel 17 Seat Ring ASTM A743 CF8M 316 Stainless Steel 1...

Page 12: ...not be responsible for any incidental special or consequential damages including without limitation lost profits or the cost of repairing or replacing other property which is damaged if this product does not work properly other costs resulting from labor charges delays vandalism negligence fouling caused by foreign material damage from adverse water conditions chemical or any other circumstances o...

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