Pressure Measurement

Pressure Gauge Failure: Causes, Solutions & Troubleshooting Guide

  • Pressure gauges are crucial components of many applications, serving as vital indicators of system performance and safety. 
  • Pressure gauges are durable, but they can malfunction for a number of reasons which affect their accuracy and reliability. 
  • Here are common reasons for pressure gauge failure:
Pressure Gauge Failure: Causes, Solutions & Troubleshooting Guide

Mechanical vibration is a leading cause of pressure gauge failure in industrial settings. The continuous shaking and oscillation can disrupt gauge accuracy and damage internal components over time. The following are some effects of mechanical vibration:

Pressure Gauge Failure: Causes, Solutions & Troubleshooting Guide 1
  • Presence of metal filings or dust within the gauge window, especially around gears.
  • Pointer detachment, particularly in severe cases of vibration.
  • Faster deterioration of internal parts, including segment and pinion gears.
  • Gradual loss of accuracy or functionality in pressure measurements.
  • Higher chance of pressure system failure as a result of faulty gauge readings.
  • Employing gauges with liquid-filled cases, typically filled with glycerin or silicone oil, to act as dampers. 
  • This fluid helps absorb vibration energy, reducing its impact on gauge accuracy. 
  • This fluid reduces the effect of vibration energy on gauge accuracy by absorbing it. It also lubricates internal gears, extending the life of the gauge.
  • To reduce vibration exposure, move the gauge away from sources of vibration. 
  • In order to properly isolate the gauge from the vibrating source, this can be accomplished by placing the gauge in a less vibratory location or by employing diaphragm seals with capillary connections for remote reading.
  • Pulsation, distinct from vibration, entails rapid and regular pressure fluctuations within the media being measured. 
  • Here are the key aspects of pulsation and how it affects pressure gauges:
Pressure Gauge Failure: Causes, Solutions & Troubleshooting Guide 2
  • Instead of giving a consistent reading, the gauge pointer may move quickly or flutter.
  • The frequent pressure fluctuations that cause intense pulsation might cause the pointer to break or become loose.
  • Because of the pressure fluctuations, it can be difficult to get a reliable and consistent reading from the gauge.
  • The gauge’s performance may be impacted by the frequent pressure variations that cause internal component wear and tear to increase.
  • Over time, pulses may impair the gauge’s accuracy and functionality, reducing its dependability.
  • Pulsation-related inaccurate readings can lead to pressure system malfunctions or failures, which can be dangerous.
  • Using gauges with liquid-filled cases can help reduce the impact of pulsation, much as treating mechanical vibration. By serving as a buffer, the liquid reduces the impact of pressure variations on gauge accuracy.
  • Pulsation effects can be minimized by using protective devices such as socket restrictors and valves. In order to reduce pressure fluctuations, these devices have a tiny hole that limits and slows down the media flow before it reaches the gauge. Socket restrictors offer a simple solution and are inexpensive and simple to install.
  • Snubbers or needle valves can be used to reduce more intense pulsation. Snubbers work in a similar way as restrictors but provide more material, orifice size, and pressure rating options. They have characteristics that can be adjusted for field customization and are less likely to clog. Needle valves are frequently used in boiler house and pump discharge applications because they efficiently reduce pulsations by throttling the medium flow.
  • Overheating or excessive temperature creates serious problems for the accuracy and usefulness of pressure gauges. 
  • Extreme temperatures can cause a variety of problems that impair gauge operation, whether they are brought on by the surrounding environment or by being close to heated system components.
Pressure Gauge Failure: Causes, Solutions & Troubleshooting Guide 4
  • The gauge’s dial and/or liquid fill may become discolored, taking on hues such as yellow, orange, brown, or black.
  • When exposed to extremely high temperatures, the gauge’s dial, casing, or window may melt in extreme situations.
  • High temperatures can cause gauge components to strain, which can result in inaccurate pressure readings.
  • The strain brought on by extremely high or low temperatures can damage the gauge’s integrity and functioning, producing readings that are not accurate.
  • Safety issues can result from pressure system malfunctions or failures caused by inaccurate readings brought on by extremely high or low temperatures.
  • Choose a pressure gauge with a temperature rating that aligns with the expected temperature range of the system. Gauges with higher temperature tolerances are better suited for extreme temperature applications.
  • To measure pressure away from extremely high or low ambient or media temperatures, use a diaphragm seal combined with a capillary. The longer the capillary run, the more heat can dissipate before reaching the gauge.
  • Attach cooling adapters, such as those with fins to increase surface area, to effectively dissipate heat and prevent overheating of the gauge. These adapters are typically easy to retrofit using threaded connections.
  • Consider using silicone oil as a fill fluid for pressure gauges in extremely hot or cold ambient temperatures. Silicone oil is less prone to discoloration in heat over time or freezing in sub-zero environments compared to glycerin.
  • Implement pigtail, coil, or mini siphons to dissipate heat away from the gauge and mitigate the effects of extreme temperatures.
  • Pressure spikes, characterized by sudden sharp increases followed by rapid drops in pressure, can pose significant challenges to pressure gauges not designed to handle such conditions.
Pressure Gauge Failure: Causes, Solutions & Troubleshooting Guide 5
  • The gauge pointer may exhibit a bent shape, resembling a fishtail or fish hook, caused by repeated impacts with the stop pin.
  • Pressure spikes can lead to the pointer being cut or broken, often due to hitting the stop pin too hard.
  • The stop pin itself may become damaged or broken from repeated impacts due to pressure spikes.
  • Repetitive pressure spikes can accelerate wear and tear on the gauge’s movement and internal components.
  • Pressure spikes can compromise the accuracy and functionality of the gauge over time, resulting in unreliable readings.
  • Severe pressure spikes may cause the Bourdon tube to split, leading to the release of media and potential safety hazards.
  • In extreme cases, pressure spikes can contribute to pressure system failures or malfunctions, posing risks to equipment and personnel.
  • Utilize a liquid-filled gauge to dampen the effects of pressure spikes and reduce strain on internal components.
  • Employ accessories such as restrictors, snubbers, needle valves, or diaphragm seals with capillaries to mitigate the impact of pressure spikes on the gauge.
  • Replace the existing gauge with one having a higher pressure range, typically double the expected maximum pressure of the system to withstand pressure spikes without damage.
  • Attach an overpressure protector to the gauge for added reassurance. This device allows setting a maximum pressure limit, automatically closing the spring-loaded piston valve if pressure exceeds the limit, preventing gauge damage. The valve reopens once pressure drops to a safe level.
  • In water/wastewater treatment and gas lines, overpressure occurs when a pressure gauge routinely reads near or at maximum range. 
  • This condition is like pressure spikes but has constant high-pressure measurements.
Pressure Gauge Failure: Causes, Solutions & Troubleshooting Guide 6
  • The gauge pointer is consistently pushed against the stop pin, indicating that the pressure readings are at or near the maximum range.
  • In extreme cases, the pressure may dislodge the stop pin due to the constant pressure exerted on it.
  • Continuous exposure to high pressures can accelerate wear and tear on the gauge’s movement and internal components.
  • Overpressure can compromise the accuracy and functionality of the gauge over time, resulting in unreliable readings.
  • Prolonged exposure to overpressure may cause the Bourdon tube to deform and split, leading to the release of media and potential safety hazards.
  • Overpressure can contribute to pressure system failures or malfunctions, posing risks to equipment and personnel.
  • Install a pressure gauge with a higher pressure range to accommodate the maximum pressures encountered in the system without reaching the gauge’s limit.
  • Utilize an overpressure protector installed to the gauge to provide an additional layer of protection. This device automatically closes if the pressure exceeds the set limit, preventing damage to the gauge and potential safety hazards.

Corrosion poses a significant threat to pressure gauges, particularly in industries dealing with harsh chemicals such as hydrofluoric acid, chlorine, and chlorinated gasses.

Pressure Gauge Failure: Causes, Solutions & Troubleshooting Guide 7
  • Damage to the gauge housing, pointer, connection, and dial, as well as discoloration and deterioration of these components.
  • Loss of accuracy/functionality.
  • Potential pressure system failure.
  • Isolate the gauge from corrosive chemicals by using a diaphragm seal made of appropriate corrosion-resistant materials. Options include 316L and 316 TI stainless steels, Hastelloy®, Monel®, Inconel®, tantalum, and titanium. These materials can also be lined with Teflon® or plated with gold for additional protection.
  • When selecting materials for diaphragm seals, consider the composition of existing wetted parts to ensure compatibility.

Clogging presents a significant challenge for pressure gauges in industries dealing with slurry, pulpy, viscous, and high-particulate media, such as paper plants, wastewater plants, and pharmaceuticals.

Pressure Gauge Failure: Causes, Solutions & Troubleshooting Guide 8
  • Gauge indication may be at or very close to zero while the system is functioning.
  • Loss of accuracy/functionality.
  • Possibility of overpressure.
  • To prevent the gauge from coming into contact with the challenging material, a diaphragm seal should be utilized. 
  • Pressure installed with a flushing port, allowing operators to clear away media during clogging or regular maintenance.
  • Think about diaphragm seals, which have smooth walls for complete flow-through and minimal dead areas to avoid media build-up.

Mishandling and abuse of pressure gauges can lead to significant damage and compromise their functionality. Despite their appearance of sturdiness, pressure gauges are not designed to withstand rough treatment.

Pressure Gauge Failure: Causes, Solutions & Troubleshooting Guide 9
  • Cracked case
  • Broken window
  • Loss of case filling
  • Crooked or bent gauge and/or process connection
  • Loss of functionality
  • It is important to put in place thorough training programs to inform staff members about the risks associated with improper gauge handling.
  • Discourage using gauges as footholds or handholds and stress the need of using correct handling skills.
  • Make sure staff members are instructed on how to connect gauges correctly. 
  • To avoid damaging the casing, tighten the gauge onto the process connection using a wrench. 
  • When tightening NPT or G connections, use the wrench flat regions for a secure fit.

Click here for Step-by-Step Procedures for Pressure Gauge Calibration

This troubleshooting guide provides step-by-step solutions to address common pressure gauge problems effectively.

1Pressure Gauge Always Showing 0Isolate the main isolation valve and open it.Isolate manifold isolation valve and open it.Identify and clear any choking in valves, manifold, or gauge.Check for any other potential issues not covered and address accordingly.Check and replace faulty pressure gauge if necessary.
2Pressure Gauge Always Showing LowThrottle main isolation valve.Throttle manifold isolation valve.Identify and clear any choking in valves, manifold, or gauge.Attend to any leakage in tubes, manifolds, or fittings.Check and replace faulty pressure gauge if necessary.
3Pressure Gauge Showing High ValueFlush the pressure gauge and reinstall in line.Check calibration and adjust using zero and span screws as needed.Investigate process side problems that could lead to high readings.Check for leakage in the system.
4Pressure Gauge Value Fluctuating HighConsider installing a pressure gauge with glycerin or with restrictor/snubber.Check calibration and adjust if needed.Investigate process side problems causing fluctuations.Check for leakage in the system.
5Pressure Gauge Showing Incorrect ReadingVerify that the pressure gauge is installed correctly and connected properly to the system.Check for any damage or obstructions that may affect the gauge’s accuracy.Ensure that the gauge is compatible with the pressure range of the system.Consider replacing the pressure gauge if it consistently shows incorrect readings despite calibration and troubleshooting efforts.Investigate any process side issues that could affect the accuracy of pressure readings.

Sundareswaran Iyalunaidu

With over 24 years of dedicated experience, I am a seasoned professional specializing in the commissioning, maintenance, and installation of Electrical, Instrumentation and Control systems. My expertise extends across a spectrum of industries, including Power stations, Oil and Gas, Aluminium, Utilities, Steel and Continuous process industries. Tweet me @sundareshinfohe

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