In industries ranging from manufacturing to energy production, pressure gauges play a critical role in ensuring the safe and efficient operation of various systems. These small yet vital devices provide valuable insights into the pressure levels within pipes, vessels, and other equipment. However, like any mechanical component, pressure gauges are not immune to failure. A malfunctioning gauge can lead to inaccurate readings, posing significant risks to both personnel and equipment.
In this article, we’ll delve into the importance of detecting pressure gauge failure early on and understanding the common causes of gauge malfunctions.
The pressure gauge seems small but is a critical part of systems across industries. The visual indication of their system pressure lets you know whether everything operates within the desired range or if a problem is imminent. A gauge not functioning accurately may lead to lower quality in your system output due to the loss of valid data and the effects of too much or too little pressure in the system. A gauge that fails can also release system fluid into the environment and lead in potential injury to employees, damage to your system requiring downtime and money to repair, and lost system output and profits.
Recognizing the indicators of pending gauge failure and the cause will help you quickly realize that the pressure readings are no longer accurate, helping you avoid undesirable outcomes.
Top 5 Causes of Pressure Gauge Failure
Top 1 Overpressure
A gauge with its pointer pressed against the stop pin indicates that it is nearing or has reached its maximum pressure. This means that the installed gauge has the wrong pressure range for the application and cannot accurately reflect system pressure. As a result, the Bourdon tube may rupture, resulting in gauge failure.
A Bourdon tube is a curved, hollow tube inside the gauge, typically made from metal. This tube responds to the system pressure and will move the connected pointer to display a pressure reading on the gauge dial.
Select a gauge with a range of two times the expected system operating pressure to provide for a larger window of measurable pressure or include overpressure protection (i.e., a relief valve) in the system preceding the gauge. For a more robust solution in harsh system circumstances, utilize a gauge with an aperture restrictor (0.3 mm) to restrict flow, or consider a diaphragm seal alternative rather than a Bourdon tube design.
Top 2 Pressure Spikes
When a gauge pointer is bent, broken, or nicked, the gauge is likely subjected to a sudden spike in system pressure caused by a pump cycling on/off or a valve opening/closing upstream. The force of hitting the stop pin can harm the pointer. This sudden pressure drop can cause a Bourdon tube rupture and gauge failure.
Examine your system design for unpredictability in pressure spikes and the consequent strain on system components, including the gauge.
Another option is to select a gauge with a more extensive pressure range to accommodate any expected spikes in pressure.
Top 3 Mechanical Vibration
A misaligned pump, reciprocating compressor, or poorly mounted gauge can result in a missing pointer, window, window ring, or back plate. You may also see black dust or scrapes on the dial from a loose pointer. The gauge movement is linked to the Bourdon tube, and vibration can cause the movement component to break, resulting in the dial no longer reflecting system pressure. Filling the system with a liquid casing will dampen the movement and remove or lessen the avoidable vibration. Use a snubber or a gauge with a diaphragm seal in extreme system conditions.
Top 4 Pulsation
Frequent, fast fluid cycling through the system creates wear on the gauge movement components. This can impair the gauge’s capacity to measure pressure and will be indicated by a fluttering pointer. Redesign your system to move the gauge within your application to minimize the gauge’s cycling speed while maintaining measurement integrity. If you cannot redesign your system, using a gauge with liquid fill, a gauge orifice restrictor or a snubber will help reduce the effects of pulsation.
Top 5 Excessive Temperature/Overheating
A gauge that is incorrectly mounted or located too close to a scorching system liquid/gas or components can have a discolored dial or liquid case fill from the breakdown of the gauge components. Elevated temperatures cause strain on the metal Bourdon tube and other gauge components, which stresses the pressure system and degrades measurement accuracy. Choosing a gauge with a different temperature rating will better suit the system’s conceivable temperature range. For extreme temperature applications, select a gauge with a diaphragm seal or a diaphragm seal with a cooling element.
As we wrap up our exploration into detecting and protecting against pressure gauge failure, it’s evident that a proactive approach is paramount. Regular inspections, calibration checks, and adherence to maintenance schedules form the foundation for a robust defense against potential malfunctions. Safeguarding against pressure gauge failure is not just a task; it’s a commitment to the well-being of your workforce and the longevity of your operations. As industries evolve and technology advances, staying ahead of potential issues becomes more crucial than ever. Let this be a reminder that the diligence invested in pressure gauge maintenance today lays the groundwork for a safer and more resilient industrial landscape.