Brochure

Thermoplastic Valves Product Guide & Engineering Specifictions
Ball Valve Troubleshooting Guide
Page 763 Suitable for Oil-Free air handling to 25 psi, not for distribution of compressed air or gas Spears
®
Manufacturing Company
Due to Material Cost Variations, Prices Sub
j
ect to Chan
g
e. Check On-line Catalo
g@
www.spearsmf
g
.com
Frozen Movements — unable, or very difficult, to open/close; sometimes
accompanied by stem break (shear)
Possible Cause
Corrective Action
Internal Obstructions; Sediment or Particle
Buildup; Solvent Cement on Ball
Over-tight Seal Carrier
Remove valve and check for solids, debris or solvent cement deposits blocking the ball
or valve interior. Check for sediment particles lodged around ball-to-seat contact areas.
Remove stem and check for the same. Clean and reinstall.
True-Union Valves - remove valve; slightly loosen seal carrier (located on inlet end of
body).
Single Entry Valves - slightly loosen single Union Nut.
IMPORTANT: Generally only a slight adjustment is required (either valve). A properly
adjusted valve should have significant resistance to operation without binding.
Chemical Attack (generally appears as
distortion, peeling, etching or bleaching
of ball sealing surfaces or other internal
components)
Check valve material (PVC, CPVC) chemical compatibility with system fluids. Be sure to
consider operating temperatures with this determination.
Internal Leaks — In-line Leakage Past Valve
Possible Cause
Corrective Action
Ball obstruction
Broken Stem
Check that the valve is in its “full-closed” position. If not, remove valve and check for
solids blocking the ball port. Clean and reinstall valve.
Remove end connector and check for ball rotation while operating valve. Replace as
necessary.
Seal Carrier Loose
True Union Valves - remove valve; CAREFULLY tighten seal carrier (located on inlet end
of body).
Single Entry Valves - CAREFULLY tighten single Union Nut.
IMPORTANT: Generally only a slight adjustment is required (either valve). A properly
adjusted valve should have significant resistance to operation without binding - AVOID
OVER-TIGHTENING!
PTFE Seat Damage or Debris Laden
Remove and disassemble valve seats. Check for excessive debris and physical damage
(nicks, cuts, scoring, etc.). Clean and replace as necessary.
Seat O-ring Displaced, Damaged or Debris
Laden
Remove and disassemble valve seat O-rings; check for physical or chemical damage.
Check O-ring chemical compatibility; clean and replace accordingly. Check for excessive
system flow rate.
Ball Damaged
Remove and disassemble valve ball. Check for physical damage (excessive nicks, scoring,
etc.) at seat sealing surface (perpendicular to ball port). Clean surface; replace ball if nec-
essary. Check for chemical damage and valve material (PVC, CPVC) compatibility.
Solvent-Cement (glue) Contamination from
Installation Spillage
Remove valve and check for glue deposits on ball or seat areas. Clean, if possible;
excessive damage may require component replacement.
Thermal Damage
(component distortion)
Check system operating temperatures, external heat sources (including direct sun), and
heat generated from system design or valve placement.