10633 W Airport Blvd. STE 200
Chaoda Group USA Co., LTD
Tel: +1 (832) 939-9944
Stafford, TX 77477
Fax: +1 (832) 939-9942
Pa
ge
24
Chaoda Group USA Co., LTD
7. Troubleshooting
Si.no. Nature of defect
cause
remedy
1
Seat leakage
1.damage of the seat due to the
presence of foreign particles
2 damage of O- ring
3.damage of the seat in weld end
valves due to improper
precautions
4.damage of the seat at high
temperature
5.improper closing of actuator
operated valves
6.damage of the seat due to rust
at the body of seat retainer
1.disassemble, clean & replace
by new seats
2. disassemble, clean & replace
by a new O-ring
3.suggest following the right
steps as per this manual
4.check for suitability of seat
material and design
5.adjust the limit screw
6.disassemble and clean the
metal seat
2
Gland leakage
1.loosening of gland nut or locking
bolt
2.damage of stem seal/ stem
washer
3.misaligment of actuator bracket
& stem
4. damage of O- ring
1.tighten the gland nut & bolt
2.replace the stem seal/ stem
washer
3.ensure correct alignment
4.disassemble, clean & replace
by a new O-ring
3
Cover flange seal
leakage
1. loosening of cover flange nut
and bolt
2.no safety guard in weld end
valves
3.misalignment of flange end &
pipeline end
1.tighten cover flange bolt and
nut
2. suggest following the right
steps
3. ensure the correct alignment
of flanges
5
Jerky operation
1. presence of foreign particles at
the seat contact area
1. clean seat & reassembly
