Anhui Star Control Instrument Co., Ltd.

Anhui Star Control Instrument Co., Ltd.

What if the pressure gauge pointer does not move?

What if the pressure gauge pointer does not move?
Common faults are:
(1)
The pointer does not move, and when the pressure rises, the gauge pointer does not move. The reason may be: the cock is not open; the cock, pressure gauge
The pipe or trap is blocked; the pointer is loose with the center shaft or the pointer is stuck.
(2)
The pointer is shaken, causing the pointer to shake due to: the hairspring is damaged; the cock or the trap pipe is partially blocked; the center
Both ends of the shaft are bent, and the ends of the shaft are rotated differently.
(3)
The pointer does not return to zero when there is no pressure. The reason for this phenomenon is that the spring bend has permanent deformation and loses its elasticity;
The pointer and the central axis are loose, or the pointer is stuck; the passage of the cock, pressure gauge pipe or trap pipe is blocked.
(4)
Incorrect indication, exceeding the allowable error, mainly due to excessive deformation of the spring tube due to high temperature or overload; gear
Loose wear; sluggish hairspring; cock leaks and other reasons.
The pressure gauge should be discontinued if it has one of the following conditions:
(1)
The pressure gauge with limited nails, when there is no pressure, the pointer cannot be returned to the limit nail after the rotation; the pressure gauge of the infinite nail,
When there is no pressure, the value of the pointer from the zero position exceeds the allowable error specified by the pressure gauge;
(2)
The cover glass of the dial is broken or the scale of the dial is ambiguous;
(3)
The seal is damaged or exceeds the validity period of the verification;
(4)
The spring tube in the watch leaks or the gauge pointer is loose;
(5)
Other defects that affect the accurate indication of the pressure gauge.
pressure gauge common
Failure and repair
method:
1.
After the pressure is removed, the pointer cannot be restored to zero.
1)
If the pointer is bent or loose, it can be corrected with tweezers and tightened after verification.
2)
Insufficient hairspring torque,
The center gear can be disengaged from the sector gear,
Rotate the sun gear shaft counterclockwise to increase the balance of the spring
Torque.
3)
The drive gear has friction. Adjust the drive gear meshing clearance.
2.
The pointer of the pressure gauge has a beating or sluggishness.
1)
The pointer rubs against the surface glass or dial.
Correctable pointer,
Thicken the gasket under the glass or twist the pointer shaft hole
Bigger.
2)
The center gear shaft is bent, the shaft diameter is not concentric, and the gear can be removed. The gear can be straightened with a wooden hammer or straightened with a flat-nose pliers;
3)
There is dirt in the meshing of the two gears, and the two gears can be removed for cleaning.
4)
The movable screw between the connecting rod and the sector gear is inactive or the movable screw is loose. The thickness of the connecting rod can be thinned with a file.
3.
Only one verification point is out of tolerance
1)
On which scale the overshoot is found,
Just stop on which scale.
Check the fit of each part on the scale point,
Drive shaft hole
Whether it is blocked or not; whether the connecting rod is flexible; whether the tooth meshing point is damaged or not, and foreign matter is excluded.
2)
When a positive error occurs at a certain point, there are often dirt and burrs due to the tooth engagement point; when a negative error occurs,
More due to the shape loss of the tooth or
Injury. If the tooth is seriously damaged, replace it with a new one. When there is no new piece replacement, the center wheel has a tooth that can change the meshing position, causing injury.
The teeth avoid the drive. If the sector wheel has a tooth, it cannot be repaired and a new one must be replaced.
4.
In use, the indication value is not stable and the pressure is significantly reduced.
At this point, first check the oil pressure at the connection between the pressure gauge and the pressure gauge checker.
If there is no oil leak,
The verifier is intact,
Description
The inside of the spring tube leaks and the scale plate should be removed for further inspection.
1)
The base itself has trachoma,
Leakage occurs gradually after long-term use.
Need to replace the same size of the base,
Measuring low pressure
force
Can be repaired.
2)
Long-term exposure to pulse pressure,
The spring tube is fatigued or leaks at the seals at both ends.
Can repair the two seals or
Retighten and rupture to scrap the spring tube.
3)
Long-term corrosion by the measured medium,
The spring tube causes a leak.
Need to use a pressure gauge that is resistant to corrosion,
when necessary
Replace the spring tube.
4)
Due to the quality of the spring tube,
There are obvious cracks or cracks.
Need to replace the high quality spring tube of the same specification.
Take appropriate protection measures
Shi.
5)
Improper selection of specifications,
The measured pressure is close to the upper measurement limit of the table.
Long-term stress causes fatigue and breaks.
Should be serious
Use a pressure gauge of the appropriate size and update the tube of the same specification if the spring tube is broken.
5.
Pressure indication value error is uneven
1)
The deformation of the spring tube fails, the displacement is not proportional to the pressure, and the spring tube needs to be replaced.
2)
The free end of the spring tube and the gear ratio of the sector gear and the wheel rod are not properly adjusted, and need to be re-inspected and adjusted.
3)
The gear splint is not in the correct position to be combined with the bottom plate. The splint should be loosened and the splint should be driven in a counterclockwise direction.
4)
Pointer displacement size,
Leading to the front or the back,
The balance springs are different.
Adjustable balance of the hairspring,
Turn the center gear to the position.
6.
When the applied pressure reaches the upper limit of the pressure gauge measurement, the pointer of the pressure gauge remains still or rarely moves, indicating the pressure
Not passed to the spring tube.
Check that the gasket connected to the gauge checker is blocking the passage at the joint.
If there is no connection
If there is a problem, it proves that the pressure gauge is clogged inside and should be cleaned.
7.
During the pressurization process, the pressure gauge pointer jumps, sluggish,
Great variation, etc.
Explain that the transmission mechanism has friction and must be disassembled.
The meter checks the meshing of the transmission mechanism and performs the necessary processing.
8.
The checked table error always increases or decreases by a fixed value. The characteristics of this error, the gauge being increased with the pressure, the error
Increase or decrease in equal amounts,
Throughout the measurement range,
The pointer reading is always a fixed value from the standard indication.
it is
Systematic error due to incorrect pointer installation.
Adjusting this error is easy,
Just re-start the needle to adjust the pointer
The position can be eliminated. If the error is very small, a slight rotation of the dial can also be solved. the reason
:1
Pipe fouling
Blocking
Wash off the dirt inside the reed pipe and use the steel wire to clear
2
Sector gear and pinion resistance is too large
Adjust the fit clearance to moderate
3
The two gears wear too much and cannot mesh
Replace the two gears
(2)
Pointer rotation is sluggish or beating
the reason
:1
The matching clearance of the transmission parts is too small, the transmission is not flexible, the clearance is increased, or the watch oil is added.
2
There is dirt on the moving parts between the transmission parts, and the transmission is not working.
Cleaning and rust removal, decontamination or replacement of transmission parts
3
Free end and connecting rod are not flexible
Adjust the connection to flexible
4
The pointer is rubbed against the dial and the watch
Correct the pointer, thicken the underside of the glass
(3)
The pointer does not turn smoothly
the reason
: 1
Sector gear tilt
Correct or replace gear
2
Pointer shaft bending
Straightening needle shaft
3
Splint bending
Correction plate flatness
4
The pillars are inclined, causing the upper and lower splints not to be parallel
Correct the strut, add or remove washers to make the splint parallel
(4)
Large pointer jitter
the reason
: 1
The measured medium has large fluctuations in pressure
Close small valve opening
2
Poor fit between gears
Adjust gear fit
3
The pointer sleeve does not fit well with the shaft
Adjust the matching gap between the pointer sleeve and the shaft
(5)
Pointer deviation from zero indication error exceeds allowable value
pressure gauge needle swing frequent causes
:
1
The fastening screw of the transmission mechanism is loose
Tighten the fixing screws
2
The buck speed is fast, the pointer is bent or loose,
Tightening and trimming the update pointer, slow down
3
The spring tube is permanently deformed
Reload the pointer and replace the new spring tube if necessary
(6)
High indication
the reason
: 1
Gear ratio misalignment
Re-adjust the transmission ratio
2
Positive zero indication is too large
Make the pointer from zero to negative zero allowable range
(7)
Low indication
the reason
: 1
Gear ratio misalignment
Re-adjust the transmission ratio
2
Spring tube has leakage
Repair or replace the spring tube
3
The pointer or the transmission has friction
Find the friction and eliminate it
4
The pressure guiding pipeline has a leak
Find out where the pipeline leaks are given and excluded
(8)
The pointer cannot indicate the upper limit scale
the reason
: 1
Small transmission ratio
Move the joint screw inward
2
The movement is fixed in a hungry position
Loosen the screw and turn the movement a little counterclockwise
3
Spring tube welding position is improper
Resolder
The gauge pointer has a beating or sluggishness
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