background image

Step 2

Opening Speed Flow Control Adjustment: The Opening speed 
flow control allows free flow into the cover and restricted flow out 
of the cover of the main valve. If recovery of pressure is slow upon 
increased downstream demand, turn the adjustment screw OUT, 
counterclockwise, 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 4).

Step 3

Closing Speed Needle Valve Adjustment: The closing speed 
needle valve regulates fluid pressure into the main valve cover 
chamber, controlling the valve closing speed. If the downstream 
pressure fluctuates slightly above the desired set point, turn the 
adjustment screw OUT, counterclockwise, increasing the rate of 
closing.

Setting the Pressure Sustaining Control

Step 1

Setting The Relief/Sustaining Control requires lowering the 
upstream pressure to the desired minimum sustained pressure.

STEP 2

Leave the downstream isolation valve fully open and close the 
upstream isolation valve until the inlet pressure drops to the 
desired setting.

STEP 3

Adjust the Relief/Sustaining Control screw IN, clockwise, until the 

inlet pressure begins to increase, or OUT, counterclockwise to 

decrease, stopping at the desired pressure (See Figure 5). 

STEP 4

Allow pressure to stabilize

Step 5 

Fine-tune the relief/sustaining setting as required as detailed in 
Step 3

Step 6

Open the upstream isolation valve to return to normal operation.

Clockwise to INCREASE 

inlet pressure

Counterclockwise to DECREASE 

inlet pressure

Figure 5 

PV20C — Pressure Sustaining Control

Counterclockwise to INCREASE 

the rate of opening

Clockwise to DECREASE 

rate of opening

Figure 4 

Flow Control

4          IOM-ACV-115-43_6115-43   2115 

EDP# 1917037 

© 2021 Watts

IOM-ACV-115-43_6115-43   2115 

EDP# 1917037 

© 2021 Watts         5

Summary of Contents for LFM115-43

Page 1: ...tion 2 Setting the 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 plumb...

Page 2: ...y valves ensure valve disc does not contact the main valve 6 Provide adequate clearance for valve servicing and maintenance Refer to valve servicing dimensions on next page 7 Avoid installing valves 6 and larger in the vertical position main valve stem horizontal Automatic Control Valves ACVs are designed for horizontal in line installation with the cover facing up main valve stem vertical Slow op...

Page 3: ... 14 16 24 26 28 30 34 40 48 48 Size in 11 4 11 2 2 21 2 3 4 6 8 10 12 14 16 C in 16 16 20 22 22 24 32 34 38 44 48 52 D in 10 10 12 14 14 16 24 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 bl...

Page 4: ...ed pressure set point by turning the adjustment screw OUT counterclockwise until downstream pressure decreases to the desired setpoint See Figure 3 STEP 6 Adjust the Surge Control by turning the adjustment screw IN clockwise to increase or OUT counterclockwise to decrease the downstream pressure surge set point See Figure 2 Counterclockwise to DECREASE downstream pressure Clockwise to INCREASE dow...

Page 5: ...kwise increasing the rate of closing Setting the Pressure Sustaining Control Step 1 Setting The Relief Sustaining Control requires lowering the upstream pressure to the desired minimum sustained pressure STEP 2 Leave the downstream isolation valve fully open and close the upstream isolation valve until the inlet pressure drops to the desired setting STEP 3 Adjust the Relief Sustaining Control scre...

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 6 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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