Understanding steam trap inspection methods

November 21st, 2018
Understanding steam trap inspection methods

Steam traps are often taken for granted – they perform a simple, but important function. When they're working properly, their presence is subdued. But when one fails, its impact can be felt throughout the plant.

In a comprehensive webinar, Inveno Engineering, LLC technical manager and steam system expert Kelly Paffel explained why inspections are essential and how to optimize the process. Here are a few questions Paffel answered in his presentation:

Why test steam trap stations?

Testing steam traps ensures that assets are optimized for performance reliability. If left alone, condensate can form within the system, degrading the quality of the steam over time. Problems within a steam trap can reduce the overall efficiency of the system, lead to future reliability challenges such as erosion and waterhammer, and increase the amount of unnecessary emissions. An optimized steam trap can actually save the facility money on energy costs, thereby reducing financial and operational risk simultaneously.

Paffel noted that facilities must decide where to focus their attention in order to produce the best results. For instance, a 25 psig steam system may actually lead to higher levels of energy loss, compared to a 250 psig system, simply because the higher pressure system is better at retaining thermal energy. Over time, this can make a significant difference to a facility's overall energy use.

Condensate will always form within a steam system, which is why steam traps are so important. If condensate isn't removed properly, it negatively impacts the performance of the entire system. Testing steam traps regularly, and with the right tools, is important because it reduces the risk of damaging assets, as well as risk to worker safety. Steam trap testing identifies safety issues before they become a hazard. Likewise, testing can pinpoint system inefficiencies and give stakeholders the ability to fully optimize their facility.

How often should facility managers test steam traps?

Facility managers need to optimize their maintenance schedules to ensure worker safety and efficient plant operation. Paffel reported that the best practice is to test steam traps every three months, until the failure rate is 3 percent or lower. Once that benchmark has been achieved, plant stakeholders should continue testing traps at least every six months.

No matter the size of the system, regular trap inspections are essential.No matter the size of the system, regular steam trap inspections are essential.

What are the best methods for testing steam traps?

The three most common methods for testing steam systems are visual assessments, temperature readings and ultrasound testing. Each is capable of identifying unique performance indicators. Therefore, Paffel recommended utilizing all three methods to achieve optimal results.

Visual inspection

A qualified reliability expert should be able to spot major issues at a glance. Poor installation, extreme asset degradation and severe failure modes are all examples of challenges that can be identified during a visual assessment.

Temperature measurement

When performing a temperature assessment, reliability stakeholders need to know if the system is in operation and if the specific steam trap station is operational. They also need to know the expected steam and condensate pressure measurements so that they can determine if the system isn't functioning properly. An infrared temperature measurement can provide maintenance personnel with a deep understanding of system performance in a matter of moments.

Ultrasound comparison

An ultrasonic reading can pick up on minute performance differences that the human ear is not capable of identifying. This method uses benchmarks to compare current ultrasound output to established optimal readings. In this way, stakeholders can determine which traps are most likely to fail in the future, so they can take preventive action. As noted by Paffel, an effective ultrasound assessment compares multiple test points to ensure an accurate reading. For example, a reliability stakeholder might test the upstream and downstream piping as well as the trap body.

Steam system assessments produce benefits in the near and long term. An optimized system will produce immediate savings in the form of energy conservation, noise reduction and plant efficiency. Over time, an optimized steam system will produce a greater number of opportunities for stakeholders to improve other aspects of the plant, such as implementing process changes and reducing risk to employee safety.

To learn more about how to optimize your plant's steam traps using a comprehensive visual, thermal and ultrasound inspection, watch Paffel's informative webinar, hosted by UE Systems.

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