[Ball Valve HD seal] 1

[gguliye]

dear All,
I am currently reading the ball valve seal options where it says HD seal is excellent for wiping scale buildup off the ball?
what is this supposed to mean? does this seat wipe the whole ball or simply sides of the ball? I am talking about V150 from Emerson

 

[gerhardl]

The answer is straightroward and geometrical:

the ball valve (segmented or not) have a movement from open to close of 90 degrees. The area that passes the sealing(s) when opening and closing will be cleaned.

As the sealings normally are one outlet side, one inlet side, all (or almost all) surface of the ball will pass the sealing. Make a scale sketch for yourself and check!

 

[gguliye]

Got it. Just need to think with calmer brain. Do u have also any idea where to use spring loaded metal seat ?

 

[gguliye]

Gerhardl,
can we tell the same thing for soft seated valve either? when the ball moves, its buildup is cleaned
Regards,

 

[gerhardl]

Depending on type of fluid (with or without contamination, dry stuff and particele content, properties of stickiness and drying at lower temperature etc. etc) you might get a 'dirty - not cleaned' ball, deposits and following abrasion and problems with the sealings over time with any valve.

Under ideal conditions you might 'clean' the ball also with soft sealings to a certain degree. This will among other things depend on the presision of fabrication and smoothness of all surfaces.

Like many other technical questions the general answer is not absolute and will depend on the actual details of use and construction.

 

[gguliye]

Thanks for your great explanation