2 replies to this topic

[ASH25320]

After replacement of steam traps I have to estimate the steam savings obtained. the traps replaced are 1/2 " thermodynamic type traps which were passing heavily(blowing steam). the service is tracing steam & inlet P=4 Kg/cm2 @148 DEG C & outlet connected to atmospheric pressure Steam condensate tank(with arrangement to condense the generated flash steam. Can somebody suggest a formula or thumb rule? Thanks in Advance...

[joesteam]

There are two factors that effect amount of steam through a blowing trap.
The choking effect of steam flowing through a small orifice
The amount of condensate present. Condensate will flash and further choke the flow and, if you have condensate flowing through the trap you don't have loss of steam!
The only real way to measure this is in a calorimeter, which you can't in the real world conditions.
SO....
I have seen using a conservative estimate of 10% of the rated full capacity of the steam trap at your differential pressure conditions. Sounds low but if you add it up over a 24/7/365 period it is a LOT of steam.

[kkala]

In addition to guide rule by joesteam, I have to point out that steam loss through a trap depends much on the trap situation, even though operators try to minimize steam loss (if possible by "setting" the trap). That is why some people support that electrical tracing can be cheaper than steam tracing, since steam losses can be 3 times the actual steam needed!
If you know the steam consumed now and that consumed before (under almost same weather and fluid conditions), you can find the steam saving by difference. Steam can be measured by installing an orifice, but you should have measured its flow rate before.