Belly Down and Eccentric

Meeting a steam plant for the first time is a bit like meeting a person for the first time (stay with me here!). Before can you consciously think, just a quick glance and you have formed an early impression and evaluated that poor person, or…err….steam system. For me it’s like a picture I have in my mind of my Dad in a knee socks and sandals combo. Tell me you wouldn’t send him back into the house. Same thing!

So for steam installations there are the “dad in socks and sandals” moments too. One example is the installed position of Y-type strainers. They are filters that prevent foreign matter entering other crucial equipment and they should be fitted with the belly in the horizontal plane. Fitted belly down, they act as a weir and fill with condensate (water), from which the travelling steam picks up water droplets, reducing the steam’s heat transfer potential significantly.

You can get the same effect with the use of concentric reducers, pipework reducers used to accommodate equipment like pressure reducing valves and control valves. Concentric reducers have a bottle neck profile, acting again like a weir and holding back the condensate. In steam systems you need to use eccentric reducers, which have a flat bottom, so that any condensate present in the pipework can travel on to the next condensate trap set unabated.

I want to mention condensate in more detail in the future, but suffice to say the mismanagement of condensate leads to many of the problems found in steam systems, including erosion, pitting and corrosion and of course water hammer and all its most devastating effects.

In précis, of my most erudite illuminations today, I would leave you with these thoughts:

• stop leaving bellies down
• concentric is a con on steam systems
• and my Dad in socks and sandals