Common faults and causes:
Â
(1) The regulating valve does not operate. The symptoms and causes are as follows:
Â
a. No signal, no gas source: 1 gas source is not open. 2 Because the water source water freezes in winter, the air duct is blocked or the filter and pressure reducing valve are blocked. 3 compressor failure. 4 gas source manifold leaks.
Â
b. There is a gas source, no signal: 1 regulator failure. 2 signal tube leaks. 3 Locator bellows leaks. 4 Adjust the mesh diaphragm damage.
Â
c. The positioner has no air source: 1 the filter is clogged. 2 The pressure reducing valve is faulty. 3 The pipe leaks or is blocked.
Â
d. The positioner has a gas source, no output: the orifice of the positioner is blocked.
Â
e. There is signal, no action: 1 valve core falls off, 2 valve core and valve seat are stuck. 3 The stem is bent or broken. 4 valve seat spool freezing or coke block dirt. 5 Actuator springs rust due to long-term use.
Â
(2) The operation of the regulating valve is unstable, and the fault phenomenon and causes are as follows:
Â
a. The air source pressure is unstable: 1 The compressor capacity is too small. 2 The pressure reducing valve is faulty.
Â
b. Signal pressure is unstable: 1 The time constant of the control system (T = RC) is not appropriate. 2 Regulator output is unstable.
Â
c. The air source pressure is stable and the signal pressure is also stable, but the action of the regulating valve is still unstable: 1 The ball valve of the amplifier in the positioner is not tightly damaged by the dirt, and the output oscillation occurs when the air consumption is particularly increased. 2 The nozzle flaps of the amplifiers in the positioner are not parallel, and the flaps cannot cover the nozzles. 3 output tube, line leakage. 4 The actuator rigidity is too small. 5 The frictional resistance is large in the movement of the valve stem, and there is a blockage in the contact part.
Replaced Parts For Case-Ih,Harvesting Blade,Harvester Spike Tooth,Auger Retractable Finger
Ningbo COMBINE Machinery Co., Ltd. , https://www.combine-harvester-parts.com