Valve trim 1

[thunderspeed]

What does the expression trim of valve mean ?
Does it refer to valve seat only ? Or it points seat and disk ?

 

[gerhardl]

I am a non-native English speaking person, so please feel free to comment and correct!

In my understanding 'trim' is used somewhat freely, and often in combination with data-sheets and specifications describing the other parts of the valve that are 'non-trim'.

Body and stem, and if necessary treatment of wetted inside of body, is generally separately described. (But not always stem.)

For ball-valves, ball and ball surface is described, for gate valves most often gate and gate surface, for globe valves globe ( but not always.)

If not anything else is described I would read trim as all wetted inserts/parts in the body not described elsewhere.

Ask originator of the description to qualify.

 

[MickMc]

From Enggcyclopedia

The operating parts of a valve which are normally exposed to the process fluid are referred to as 'valve trim'. Usually these parts are subject to wear and degradation and hence are replaceable. Usually parts like stem, closure member, seating surface etc. are called as valve trim. The parts such as body, bonnet, yoke etc. are not considered as trim.

Following represents a list of parts, which can be considered as trim for different types of valves.

Type of Valves Valve Trim

Angle Valves: Stem, Seat, Disc, Disc nut, back-seat bushing
Disc Valves: Disc, Disc nut, back-seat bushing
Gate Valves: Stem, Seat, wedge, back-seat bushing
Globe Valves: Stem, Seat, Disc, Disc nut, back-seat bushing
Lift type check Valves: Seat ring, Disc, Disc guide
Swing type check Valves: Seat ring, Disc, Disc holder, Disc holder pin, Disc nut, Disc nut pin, side plug,carrier pin