Introduction to Steam Trap Testing

A short introduction to testing steam traps with ultrasound using the SDT270 ultrasound detector.

[@KrashTWazo]

great video, thanx for sharing

[@bilalpisces1989]

Good. Thanx 4 sharing

[@tariqalavi]

For testing steam trap using temperature only, what do you expect the temperature on down stream of trap? if downstream is on atmosphere pressure. By Keeping upstream pressure 5bar at 250F as you mentioned. I thing it should be at saturated temperature I.e 212F (or around 190F keeping in view 10% heat loss). You have mentioned it is faulty. Plesae explain. Thanks

[@paulk3961]

Greetings Tariqalavi. When inspecting steam traps using temperature only, please recall that after the trap, most condensate systems are not under pressure, and therefore at or below 100 C. The upstream side of the trap is almost always under some pressure, therefore it should be significantly higher then 100 C. With a few years of experience behind me testing traps, I can say that I have never looked for a particular downstream temp. but I was looking for a large delta between the upstream and downstream temperature. I hope this assists you in monitoring steam traps.

[@georgeyetka7689]

So I could use a flir camera to trace and anything with no delta or an extreme delta we would use an SDT340 to measure? This would be the fasted method?

[@allanrienstra5176]

Hey George, I don't know about using a FLIR camera. Maybe a FLUKE will due just fine if you have one. Temperature is a key element to good surveys of steam traps and taking comparative temperature readings upstream, downstream, and directly on the steam trap can give some indication of proper function as well. But temperature alone will not reveal chattering valves, blocked or open traps, and proper purging. Therefore, the SDT340 is equipped with both ultrasound for listening and temperature for feeling. But temperature is not the first indicator of a problem in a steam trap and may even be misleading. Since a steam trap works on the basis of "collect" and "purge" the prime symptom we listen for is turbulent flow (or the lack thereof). The SDT340 hears that (or hears that there is NO flow) and from there we determine the trap cycles properly.

[@malvernjones2445]

Thermodynamic steam traps do not work on the difference in temperature. They operate on the difference in flow velocity (Dynamics)

[@allanrienstra5176]

Dear Malvern Jones, thank you for watching our video and adding your comment. Indeed, you highlight an operational point that I could have explained more precisely. The relationship between velocity and pressure, first described by Bernoulli, is certainly what drives the purge cycle in this style of traps. However, temperature also plays a role as pressure, and consequently flow velocity are both dictated by temperature changes. As more condensate gathers the internal temperature drops. This causes steam in the pressure chamber to also cool and condense. The resultant change in pressure (caused by cooling temperatures) opens the disc allowing the condensed steam and gases to evacuate.