"Vacuum service" means, for the purpose of Subpart Q of this 35 Ill. Adm. Code 215, 218 and 219, equipment or a component which is operating at an internal pressure that is at least 5 kPa (0.73 psia) below ambient pressure.
Ill. Admin. Code tit. 35, § 211.6910
Added at 17 Ill. Reg. 16504, effective September 27, 1993