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:

Factor No.1: Mechanical Vibration

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:

Visible Signs of Mechanical Vibration

• Presence of metal filings or dust within the gauge window, especially around gears.
• Pointer detachment, particularly in severe cases of vibration.

Risks Associated by Mechanical 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.

Remedies for Gauges that Are Vibrating Mechanically

Gauges with Liquid-Filled Case

• 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.

Relocation of Gauges 

• 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.

Factor No. 2: Pulsation

• 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:

Visible Signs of Pulsation

• 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.

Problems Induced by Pulsation

• 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.

Remedies for Gauges that are Pulsating

• 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.

Factor No. 3: Extreme Temperature

• 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.

Visible Symptoms of Extreme Heat

• 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.

Risks Posed by Extreme Temperatures

• 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.

Solutions for Gauges in Extreme 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.

Factor No. 4: Process Pressure Spikes

• 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.

Visible Signs of Pressure Spikes

• 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.

Risks Posed by 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.

Solutions for Gauges Experiencing Pressure Spikes

• 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.

Factor No. 5: Overpressure in the process

• 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.

Signs of Overpressure

• 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.

Risks posed by Overpressure

• 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.

Ways to Resolve Overpressure in Gauges

• 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.

Factor No. 6: Corrosion

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

Visible Signs of Corrosion

• Damage to the gauge housing, pointer, connection, and dial, as well as discoloration and deterioration of these components.

Risks Created by Corrosion

• Loss of accuracy/functionality.
• Potential pressure system failure.

Solutions for Gauges in Corrosive Environments

• 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.

Factor No. 7: Clogging

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.

Visible Signs  of Clogging

• Gauge indication may be at or very close to zero while the system is functioning.

Risks Created by Clogging

• Loss of accuracy/functionality.
• Possibility of overpressure.

Solutions for Gauges Measuring Clogging Media

• 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.

Factor No. 8: Mishandling/Abuse of pressure gauge

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.

Visible Signs of Mishandling

• Cracked case
• Broken window
• Loss of case filling
• Crooked or bent gauge and/or process connection

Risks Created by Mishandling

• Loss of functionality

Solutions for Gauge Mishandling/Abuse:

• 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

Step by Step Troubleshooting Guide for Pressure Gauge Problems

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