... complex intelligent-control instrument that is a combination of pneumatic components . Users must choose accessories detailed according to ... their requirements , and note ontechnology contracts1). Pneumatic Actuators , (1) Double-Acting ,(2) Single-Acting ... Explosion-Proof Type4) Locator: (1) Electric Locator, (2) Pneumatic Locator, (3) Current Signal,(4) Air Pressure Signal ,(5 ...