Hypertherm HD4070 Rev.1 - Manual (Page 141)

OPERATION
4-16 HyPerformance HD4070 Instruction Manual
Install consumables
Apply a thin coat of silicone grease on all o-rings.
Do not overtighten parts! Only tighten until mating parts are seated.
Clean current ring using
a cotton swab with water
or 3% hydrogen
peroxide.