Rising Stem Globe not rotating

[Isha90]

Hand wheel operated Rising Stem Globe not rotating, when checked Stem got locked with Yoke Bush. Material Stem ASTM A410 Type 410, Yoke Bush A582 Type 416
Will it be due to dust entry into Stem thread.
Will it be due to thread damage due to excess torque
Will it be due to differential expansion of Stem & Yoke Bush thread
Could anybody guide me in finding out probable cause of failure

 

[mk3223]

May try to spray WD-40 to the thread.
A good question to the Maintenance.

 

[gerhardl]

Hi Isha 90,

The answer is 'yes'. It could be any of the above causes, and in addition not only one alone.

You mention Stem Globe not rotating. Is the stem attached directly to the globe? Could the globe stick to the valve seat?

Regardless of possible causes the most common cause of 'sticking' stem is the use of excessive force and /or lacking routine of testing the valve operation at intervals.

 

[Isha90]

Thank you