The needle valve should regularly check the oil level in the oil level gauge, add oil to the lubricator as appropriate, and regularly remove the condensed water and impurities accumulated at the bottom of the water filter cup; check the air source pressure and adjust the flow rate of the one-way throttle valve. The valve has sufficient opening and closing force, and the action is flexible; check whether the detection hole is leaking or leaking water. In daily use, the needle valve should regularly check the oil level in the oil level gauge, add oil to the lubricator as appropriate, and regularly remove the condensed water and impurities accumulated at the bottom of the water filter cup.