|
Failure |
Reason |
Methods |
|
Wear of the Body |
(1)Fulid speed is too high
(2) Particle in fluid
(3)Cavitate and Flash vaporization |
(1)Increase the size of trim,to reduce fulid speed.
(2)Exchange body with the streamline structure to avoid attacking.
(3)Increase rigidity of body material.
(4)Change trim structure to reduce pressure. (5)Exchange with low-pressure
to avoid cavitating. (6)Welding with the stainless. |
|
Wear of the Trim |
(1)Fulid speed is too high
(2)Particle in fluid
(3)Cavitate&Flash vaporization |
(1)Increase trim size to reduce fulid speed. (2)Change
rigidity of trim material.
(3)Change the structure of trim to reduce fluid speed.
(4)Exchange with valve or trim to avoid cavitating.
(5)Exchange with the streamline structure to avoid attacking. |
Leakage occurred between plug and seat ring
|
(1)The surface of plug,seat ring is bad(wear,corraded)
(2)The force of actuator is too small
(3)The screw of seat ring is corraded or loose |
(1)Improve the connection surface(grind).
(2)Adjust the connection of actuator with stem.
(3)Screw tightly or maintenance,replace plug,seat ring. |
|
Leakage occurred between seat ring and body |
(1)Screw moment is too small
(2)Surface is bad(unclean,glabrous degree is bad)
(3)Gasket isn't matched
(4)Body has the eyelet |
(1)Increase screw moment.
(2)Reprocesse and clean.
(3)Maintenance or replace gasket.
(4)Sometimes the eyelet is easy to occurred in the casting ,please welding
after grinds. |
|
Leakage of Padding |
(1)Glabrous degree of stem is bad
(2)Stem is curving
(3)Padding cap isn't pressed out
(4)Padding type or structure is bad
(5)Padding layer stack too high
(6)Padding cautery,has pit
(7)Padding gland distort,damage |
(1)Grind the stem smoothly.
(2)Press the stem to straight.
(3)Screw firmly again.
(4)Choose padding again and replace the padding. (5)Install interval
ring,reduce the high of padding. |
|
Wear of sliding |
(1)System is precarious
(2)Cotact force too big
(3)Misalignment
(4)Surface glabrous degree is bad
(5)Material chosen is bad |
(1)Improve stability.
(2)Increase bearing size.
(3)Reprocesse and maintenance.
(4)Grind the surface again.
(5)Choose better guidance piece and material. |
|
Leakage between bonnet and body |
(1)Screw moment is small
(2)Surface glabrous degree is bad
(3)Bolts leakage |
(1)Increase screwing force.
(2)The surface of gasket cleanness.
(3)Nearby the stud valve body cann't have the eyelet. |
|
The connection of stem come away or break off |
(1)System astaticism
(2)Pin connection is bad
(3)Vibration or astaticism |
(1)Fasten firmly with pin conncetion.
(2)Eliminate vibration. |
|
Piston ring seal outside-leakage |
(1)Cylinder glabrous degree is bad or inner-diameter
is too big
(2)Piston ring installment is bad,no seal
(3)Seal ring type is bad
(4)Seal ring work temperature is too high
(5)Use-time too long,seal ring is destroyed |
(1)Grind cylinder,change the inner diameter.
(2)Install correctly.
(3)Replace seal ring by request.
(4)Design by high temperature
(5)Replace seal ring. |
|
Valve without action |
(1)No air or air supply not enough
(2)Actuator failure,leakage
(3)Adjust positon haven't input signal
(4)Air supply pipe break off,distortion
(5)Air supply pipe break,distortion
(6)The flow direction is not correct,force is too big fall plug off
(7)Stem or bearing locked
(8)The position or E/P transmitter failure
(9)Trim is amaged or locked
(10)Plug is locked in the seat ring |
(1)Examine and maintenance air source.
(2)Maintenance failure component.
(3)Maintenance failure component.
(4)Replace.
(5)Maintenance or replace.
(6)Install according to the direction of arrowhead.
(7)Maintenance or replace.
(8)Maintenance or replace.
(9)When the friction force too big to be locked,loose,luricate,and install
again.
(10)Reprocesse,maintenance or replace. |
