Generating steam requires tons of energy and financial resources, which is why it only makes sense to want your steam system to run as efficiently as possible. Besides using quality parts for key components like a pressure relief valve, it is also vital to make sure they remain in good operating condition. One such component that warrants close attention is steam traps in industrial operations, which play an integral role in the safety and efficiency of steam systems and the overall optimisation of a plant’s productivity. Therefore, any issues that could impede their proper functioning, such as ineffective heating, steam loss or leakage, or water hammer, must be addressed immediately to prevent failure.
The consequences of steam trap failure
Failure among drip and process steam traps can have a significant impact on a system, and it commonly manifests as either a failed closed or failed open incident. The former is when a steam trap fails while closed and causes condensate to move back into the system. This situation often results in a flooded heat exchanger in process traps and reduces their ability to transfer heat. Should these process traps fail in a high-capacity application like coils while cold air is being introduced into the system, freezing and sorts of damage may follow.
Meanwhile, the latter occurs when a trap fails in the open position and causes steam to flow straight into the condensate return system and potentially flood it, causing a water hammer phenomenon. This issue is less severe in gravity-vented systems since the steam leakage simply vents to the atmosphere, yet it still wastes energy and increases operational costs.
Benefits of periodic steam trap testing
1. Boosts system performance
Faulty steam traps introduce inconsistencies in system performance that largely affect production rates and product quality. Hence, proper testing and routine maintenance are the only ways to make sure the system operates at maximum efficiency and produces the desired results.
2. Achieve higher energy savings
Steam trap testing helps identify and repair faulty traps to prevent further energy losses. Regularly conducting these tests is proven to save much in energy costs and give much-needed peace of mind that a system is operating as expected.
3. Reduce maintenance costs
Discovering failed steam traps as early as possible prevents more damage from occurring in a system and the costly repairs that come with them, ensuring the longevity of the plant’s equipment and minimising downtime.
4. Improve overall safety
Malfunctioning steam traps pose severe safety risks to both personnel and equipment, which can largely be mitigated by frequent testing to maintain a safe working environment for all.
5. Adhere to regulatory compliance
Industries that leverage steam systems must typically observe strict regulations regarding efficiency and safety. Steam trap testing can significantly help with maintaining compliance with these standards and steer clear of avoidable fines and penalties.
Common steam trap testing methodologies
There are several methods to test a steam trap’s operating condition and check if it is still functioning properly. These include:
1. Visual observation
Visual observation is limited in its scope compared to the other tests, but it is still an important first step that should not be overlooked. This is because certain issues often come with visual signs like the absence of any condensate discharge, abnormal quantities of steam leakage from the trap, and so on.
It is important to note that these assessments are only applicable to open systems since recovering condensate in closed systems, for example, is simply not possible due to the piping being in the way. This obstacle can somewhat be overcome by putting a sight glass on the trap outlet, which can provide a visual indication. External inspection of steam traps can also reveal issues affecting the gasket, connection joint, and pinhole.
If a condition cannot be clearly determined visually, conducting other tests will then be required to reach an accurate diagnosis.
2. Temperature testing
The next step in testing for steam trap failure is to measure its inlet condensate temperature. This variable should be close to that of saturated steam save for cases where there is intentional subcooling. Checking the temperature can be incredibly useful when determining if a trap is blocked or its capacity is inadequate since these problems lead the condensate to back up and consequently lower the trap’s temperature.
If there is a low temperature reading while the application is running, it generally indicates that either the steam trap is undersized, experienced a strainer discharge/blocked trap failure, or has an incorrect pressure orifice. In some cases, it could also potentially indicate a “stall” or negative pressure differential condition in situations where a modulating control valve is supplying the equipment.
Do note that identifying steam trap leaks using temperature measurement may result in erroneous analysis since condensate at high temperatures flashes into steam when fed into lower pressure systems. The temperature of this flash steam and a live steam leak are virtually the same, making it impossible to differentiate between the two.
3. Sound testing
As condensate flows through a steam trap, it generates sounds (typically one with a low pitch) and vibration. Once a trap no longer functions as intended due to issues like blockage, wear and tear, and other factors, these sounds also change. Therefore, identifying this difference can be an effective means of determining a steam trap’s condition.
For instance, bucket traps may have their vent hole blocked by scale and floating debris, which results in the inverted bucket temporarily locking shut and potentially causing freeze-ups and blocked discharge. A live steam leak also produces a unique sound which is best described as the difference between a “whistle” and a “wave.” The former is a high-pitched and vapour-based sound that cannot be reproduced with a liquid, whether it is small, like a drip from a water faucet or something larger, like an ocean wave.
Overall, if the sound changes from a low to a higher pitched sound that is usually produced by steam flow, that indicates the steam trap may be experiencing a leakage or have lots of flash steam.
Conclusion
Steam trap testing is crucial for maintaining the efficiency and safety of steam systems as it quickly identifies malfunctions that can lead to energy loss, equipment damage, or unsafe operating conditions. By enabling early repairs and maintenance, testing allows businesses to implement proactive maintenance strategies that protect their investments and maintain system integrity over the long term.
Techmatic Controls is the leading supplier of industrial products you can trust to source durable and high-performance steam traps and heating and cooling-related pipeline solutions. With our commitment to quality and reliability, we guarantee that all our offerings will meet your expectations and application requirements.
