If it's on the valve casing and you don't want to exacerbate it you can get a valve guard

https://www.amazon.com/dp/B0002E583I/ref=cm_sw_r_cp_apa_glt_fabc_M4SVWM30K2FCH1P0JGWV?psc=1

https://www.amazon.com/dp/B00V3A69ZQ/ref=cm_sw_r_cp_apa_glt_fabc_6BQQCTG238B1FPK6RXZM