"gunk" on stem of regulator valve

[Freezer Burn]

The stem for manual operation of a regulating valve seized and couldn't turn the valve. After pulling it apart, found the threads on the stem full of "gunk". Wiped it off, but what is it and were did it come from. How do I keep it from happening again? Have a strainer before the valve.

[US Iceman]

You did not give us much information to consider.

When you post a question, you need to provide more details such as; where is the valve installed? (liquid, suction, discharge, hot gas, or an oil line?)

What refrigerant is being used?

What are the operating conditions where the valve is installed? (pressure, temperature, etc.)

See what I mean? The more information you can supply helps us to help you. Odds are, one or more of our members may have already seen something like this.

[Freezer Burn]

Thanks, this may help.
R717 system, liquid line, 125 psi, 90 degree F

[nh3wizard]

Could be anything, oil, never seize, threadlocker...

[keepitcool]

Could be graphite packing also. What color was it?