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Valve Disassembly Instructions

 

Before undertaking valve disassembly, it is recommended to gather the following tools to aid you during the process:
• Small & large adjustable wrenches
• Screwdriver set
• Machinist fine metal file
• Fine wire brush
• Bench vise
• Basic valve IO&M manual
• Hammer & dull cold chisel
• Heavy-duty ratchet & socket set
• Hexagonal wrench set
• 320 grit/fine Emery cloth
•  Appropriate technical bulletins for  

valve start-up procedures.

1.  Isolate the valve from line pressure and depressurize it to ensure safe working conditions. Disconnect any electrical  

connections if so equipped.

2.  Carefully remove Position Indicator or Limit Switches if equipped. Remove all tubing, fittings, and Control Pilots  

necessary to easily access and remove the cover. 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 by lifting straight up. 

a.  Large diameter valves may require a lifting “eye” bolt to be installed in the valve stem accessory threads located on the very  

top of the valve stem.

5.  Before removing Stem Nut, examine stem threads for mineral build-up. Remove deposits with a fine wire brush. Extreme care should 

be taken not to damage the finish on stem guiding surfaces when disassembling. Avoid applying pipe wrenches to top or bottom 

stem guide surfaces.

VALVE COVER

BRASS BAR STOCK
(ANGLE UPWARD)

HAMMER

8          IOM-ACV-127-8_6127-8 2115 

EDP# 1917065 

© 2021 Watts

Summary of Contents for LFM127-8

Page 1: ...on 2 Setting the Altitude Controls 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 ...

Page 2: ...lowing instructions on Technical Bulletin Start up of an automatic control valve requires that proper procedures be followed Time must be allowed for the valve to react to adjustments and the system to stabilize The objective is to bring the valve into service in a controlled manner to protect the system from damaging over pressure installed sensing line and directs pressure into and out of the co...

Page 3: ...wly open the valve See Figure 1 STEP 3 Pressure the line by opening the upstream isolation valve slowly Air is vented through the air bleed valve Tighten the fitting when liquid begins to vent See Figure 1 Repeat the process until no air is trapped in the system Globe Angle Size in 11 4 11 2 2 21 2 3 4 6 8 10 12 14 16 20 24 A in 16 16 20 22 22 24 32 34 38 44 48 52 56 56 B in 10 10 12 14 14 16 24 2...

Page 4: ...r 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 See Figure 2B 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 2A STE...

Page 5: ...red setting STEP 10 Adjust the Sustaining Control screw IN clockwise until the inlet pressure begins to increase See Figure 4A or OUT counter clockwise See Figure 4B to decrease stopping at the desired pressure STEP 11 Allow pressure to stabilize STEP 12 Fine tune the sustaining setting as required as detailed in STEP 10 STEP 13 Open upstream isolation valve to return to normal operation IOM ACV 1...

Page 6: ...e 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 valv...

Page 7: ... 2 1 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 Diaphragm is damaged Conduct diaphragm seal test repair and replace if necessary Main valve stem assembly corroded damaged Inspect stem assembly clean replace if necessary Blockage in main valve Perform freedom of movement test if...

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 c...

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 1...

Page 11: ...l 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 17A...

Page 12: ...ot 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 ov...

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