Organizations that depend on steam to power their processes are realizing the importance and challenge of scheduling regular steam trap testing. Here is the steam trap inspection checklist to get the best results.
by Isabell Berry
The Department of Energy estimates that 8-15% of steam traps fail annually. A failed trap is impossible to diagnose by sight or sound as the failure evidence is encased inside the pipes and traps. The exception is when closed failures cause explosions, like the one in Ontario a few years ago where a 100-ft section of 24" pipe filled with 54,000 lbs of condensate water, and when it burst it was thrown half a mile due to the strength of the hammer.
Most facilities test all of their traps on a regular basis, varying from every few hours to every few months to as little as once a year. This, however, is a costly and time consuming task and the accuracy of these manual tests is very low. To ensure maximum benefit of steam trap testing we have come up with a little steam trap preventative maintenance checklist:
To ensure maximum accuracy, the test should include temperature, visual, and sound readings. Records should be kept of readings from all tests to allow the inspector to have the context that will help to determine if the trap is failed or not.
The next point of our steam trap inspection checklist is that testing should be done once a month for traps between 50 psi and 150 psi. Once a quarter for traps under 50 psi, and weekly for traps over 150 psi. The reason for this is that steam at higher psi produces less condensate but poses greater danger in case of explosion. Open failures in traps at lower psi don’t cost as much on a daily basis but , and closed failures tend to be much less dangerous.
To determine whether it is an open failure it is recommended that you use both ultrasound and temperature data. In the case of an open failure, you will see that the delta between temperature above the steam trap and in the condensate line, will usually diminish. Additionally, you won’t be able to hear the trap opening and closing anymore.
To diagnose a closed failure you may find that both pipe and condensate temperatures decrease significantly, you may find that temperatures become reversed, you may find a large increase in sound, or no change at all.
The best way to diagnose open and closed failures is through the use of an artificial intelligence engine that can analyze all data points including psi, orifice size, type of trap, as well as reference historical data and data of traps in the same system and in the vicinity.
6. In addition to auditing whether or not the trap is failed, it is good practice in steam trap inspections to regularly assess the other trap data (size, type of trap, and pressure). All measurements should be reviewed to assess whether the trap chosen is best suited for that location and function.
7. Another point worth noting in the steam trap inspection checklist is that it is important that inspectors wear protective clothing, glasses and gloves. Pipes may be hot, and the most dangerous steam leaks may be invisible as they are above the temperature of condensation.
8. A steam trap failure will affect more than just the trap itself. It will cause traps around it to work harder, it could cause temperature and/or pressure to decrease in the entire system or areas close to the failure. A steam trap failure may cause the boiler to have to work harder and potentially reduce the life expectancy of the boiler. A steam trap failure could have significant effects on the processes closest to it; for example, if a steam trap that is located just after an essential internal process fails, it could create issues for that entire process as it could be under-served in power, or not be able to maintain a stable or sufficiently high temperature. When checking steam traps, it is beneficial to check any changes in steam temperature, pressure, or sound in all steam traps in the vicinity as well.
This is a steam trap maintenance checklist that we have created in our experience talking to hundreds of organizations that use steam, as well as discussions with steam auditors, steam system manufacturers, safety inspectors and more. Ultimately, some of the challenges around steam trap testing was what led Pulse CEO Thomas Uhlenbruck to focus on steam trap IoT sensors in the first place. He saw the need for a real time steam trap monitoring solution.
The complexity of actually determining failures required an AI backend that the team worked on for years to ensure a much more accurate failure detection than any form of manual testing can achieve. It is encouraging that more organizations are understanding the need for frequent steam trap testing; when they see how easy and reasonably priced steam trap monitoring can be, it isn't a very big leap to bring Pulse on board.
