Basınç göstergesinin 5 yaygın arızasının analizi

Pressure gauges are essential instruments used in various industries to measure pressure. However, over time, they may encounter several issues that can impact their accuracy and reliability. Here, we analyze five common pressure gauge faults, their causes, and troubleshooting methods.

1. Pointer Failing to Return to Zero (Large Zero Error)

This issue occurs when the pressure gauge pointer doesn’t return to the zero mark when there is no external pressure. If the deviation exceeds the allowable range, it can significantly affect measurement accuracy, shorten the lifespan of the gauge, and potentially pose safety risks.

Causes and Solutions:

• Excessive Load Pressure: If the Bourdon tube has been subjected to excessive pressure, it can become permanently deformed, causing the pointer to fail to return to zero.
  Solution: Remove and re-zero the pointer. If calibration doesn’t resolve the issue, replace the Bourdon tube.
• Loose Mounting Screws: Loose screws can cause the gauge to wobble, leading to inaccurate readings.
  Solution: Tighten the mounting screws using specialized tools.
• Missing Teeth in the Pressure Gauge Gear: This occurs when there are too few meshing teeth between the sector gear and the gear shaft.
  Solution: Replace the worn or missing gears.
• Deformation of the Pointer: Excessive load pressure can cause deformation of the pointer.
  Solution: Replace the deformed pointer.
• Clogged Internal Cavity: Over time, the internal cavity may become clogged, affecting the gauge’s performance.
  Solution: Clean the internal cavity.

2. Pointer Behind the Zero Pin

After prolonged use, the pointer may sometimes position behind the zero stop on the dial, preventing it from returning to zero. This can occur due to a large gap between the pointer and the dial or insufficient pointer strength.

Cause and Solution:

• Cause: Vibrations may cause the pointer to overshoot the stop pin and fail to reset.
• Solution: Gently lift the pointer to the zero stop pin and adjust the gap between the pointer and dial to prevent this issue from recurring.

3. Pointer Moving Beyond Allowable Error Due to Tapping

Some pressure gauges may move beyond the allowable error when tapped during pressurization or depressurization. This is often caused by factory assembly issues, corrosion, or wear.

Causes and Solutions:

• Low Initial Torque During Assembly:
  If the spring tension is too low, the pointer may move excessively.
  Solution: Adjust the spring tension to increase the initial torque.
• Corrosion of the Hairspring:
  Prolonged exposure to harsh conditions can corrode the hairspring.
  Solution: Replace the corroded hairspring.
• Worn Gears:
  Over time, gears may become worn and affect movement accuracy.
  Solution: Adjust the meshing position of the gears or replace severely worn gears.
• Dislodged Hairspring Seat or Pin Holder:
  If the hairspring seat or pin holder has fallen off, the hairspring may lose control.
  Solution: Reinstall the hairspring seat or pin holder to its original position.
• Loose Dial Fixing Screws or Riveting Issues:
  A loose pointer or rivet may cause erratic pointer movement.
  Solution: Retighten the screws or rivets.

4. Unstable Pointer Deflection

Unstable pointer deflection can result from erratic movement or jumping of the pointer.

Causes and Solutions:

• Erratic Pointer Movement: Dust entering the sector gear or pinion may cause jittery pointer movement.
  Solution: Clean the gear or adjust the sector gear alignment.
• Pointer Deformation: If the pointer becomes deformed, it may contact the dial, causing erratic movement.
  Solution: Adjust the pointer shaft to prevent contact with the dial.
• Pointer Lag or Jumping:
  This can occur due to rust, tight moving parts, or uneven pressure within the gauge.
  Causes and Solutions:
  • Rust or Dust Buildup:
    Rust or debris accumulation can jam the transmission components.
    Solution: Clean rust and debris or replace rusted parts if necessary.
  • Tight Moving Parts:
    Tight components can cause rough movement.
    Solution: Adjust the clearance between the components and apply appropriate lubrication.
  • Uneven Pressure in Bearing Holes:
    If the bearing pillars are different lengths or skewed, the transmission mechanism may not work smoothly.
    Solution: Adjust the bearing pillars to ensure equal length or alignment.
  • Tie Rod Misalignment:
    If the tie rod holes are misaligned, the rod can become stuck.
    Solution: Align the holes to restore flexibility.
  • Non-Concentric Wheel Diameter:
    If the wheel diameter is not aligned with the wheel axle, it can affect pointer movement.
    Solution: Straighten the wheel axle.

5. Pointer Failure Under Load

Pressure gauge pointers may fail to move correctly under load, leading to inaccurate readings.

Common Scenarios and Solutions:

• Scenario 1: The pointer doesn’t move under load.
  Solution: Check for loose pins or screws and secure them.
• Scenario 2: The pointer moves normally but gets stuck when approaching 1/3-3/4 of the measurement limit.
  Solution: Inspect and replace worn-out internal components or ensure proper damping.
• Scenario 3: The pointer moves under load but fails to return after removing the pressure.
  Solution: Reinstall loose pins or screws that connect the Bourdon tube to the tie rod.

Çözüm

Pressure gauge faults can occur for various reasons, from mechanical issues to environmental factors. Regular maintenance, proper calibration, and timely replacements are essential to ensuring the reliable operation of pressure gauges. By understanding the common causes and solutions for these issues, you can prolong the life of your pressure gauge and maintain accurate measurements.