Intrinsically Safe Explosion-proof System 5 Port Solenoid Valve Exia@ BT4 (TIIS approved product) This product has been certified as an intrinsic safety type system consisting of an electromagnet for a solenoid valve in combination with a safety retainer, for type approval as an explosion proof electric apparatus by Technology Institution of Industrial Safety (TIIS). Can be used as a certified intrinsic safety type product only in Japan. Series 51-SY5000/7000/9000 CAT.ES11-90B B