Troubleshooting valdisk 150 valves – Flowserve BX 150 User Manual
Page 7
37-7
Failure
Probable Cause
Corrective Action
Valve moves to failure
1. Failure of actuator O-ring
1. Replace actuator stem O-ring
position, excessive air
2. Failure of sliding seal assembly
2. Repair or replace sliding seal assembly
bleeding from transfer case
Jerky shaft rotation
1. Overtightened packing
1. Retighten packing box nuts to slightly over
finger-tight for V-ring packing, 14 ft-lbs for
braided packing
2. Improper adjustment of lever arm on
2. Readjust lever arm (see step 1 in the
shaft causing arm to contact transfer case
“Remounting Actuator” section)
3. Cylinder wall not lubricated
3. Lubricate cylinder wall with silicone lubricant
4. Worn piston O-ring allowing piston to
4. Replace O-ring; if galling has occurred
gall on cylinder wall
replace all damaged parts
5. Worn actuator stem O-ring causing
5. Replace O-ring; if actuator stem is galled
actuator stem to gall on stem collar
replace it
6. Worn (or damaged) thrust bearings, shaft 6. Disassemble and inspect parts; replace
bearings or packing followers
any worn or damaged parts
Excessive leakage
1. Improper adjustment of external stroke
1. See “Remounting Valve to Actuator”
stops
section
2. Worn or damaged seat
2. Replace seat
3. Damaged disc seating surface
3. Replace disc
4. Improper handwheel adjustment acting
4. Adjust handwheel until disc seats properly
as limitstop
Leakage through line
1. Dirty line gasket surfaces
1. Clean gasket surfaces and reinstall valve
2. Improper sealing of line flanges
2. Tighten line flanges evenly and
completely (see Table 1 for proper torque)
3. Flange or pipe misalignment
3. Clean body bore and stem, replace packing
Leakage through
1. Loose packing box nuts
1. Tighten packing box nuts to slightly over
packing box
finger-tight for V-ring packing, 14 ft-lbs for
braided packing
2. Worn or damaged packing
2. Replace packing
3. Dirty or corroded packing
3. Clean body bore and stem, replace packing
Disc interferes with body
1. Disc installed upside down
1. Reinstall disc
2. Worn thrust bearings
2. Replace thrust bearings
Disc interferes with line
1. Cement lining or heavy schedule pipe
1. Modify line to allow proper disc clearance
Valve slams, won’t open,
1. Improper valve installation
1. See step 2 in “Installation” section and
or causes severe water
correct flow direction
hammer
Shaft rotates, disc remains
1. Missing or broken taper pin
1. Replace taper pin
open or closed
2. Broken shaft
2. Replace shaft, make sure disc does not
overstroke and contact disc stop
Actuator operates, shaft
1. Broken internal actuator parts
1. Refer to appropriate actuator Maintenance
does not rotate
Instructions
Troubleshooting Valdisk 150 Valves