Use of Automatic air start valve
>Act as stop valve which supplies and shut off main start air into the main start air line
>Act as non return valve which prevent the blow black of exhaust gas if the starting air valve is leaky
>Prevent flame by the use of a flame trap incorporated with it.
>Shutoff starting air supply automatically, if the engine is on fuel or when the engine is on stop
Working of Automatic air start valve
>Here in figure shows a simple diagram of a automatic start air valve
- During the normal condition ie engine is at stop, the valve spindle is screwed up into the closed position, holding the valve closed against the seat.
- When the engine is prepared for starting, the valve spindle is moved to the automatic position. The spring holds the valve shut.
- When the start air valve at the air receivers is opened, air enters the valve body (here it shows 'start air in')and flows to the underside of the valve through the balancing bores. The air pressure on the underside of the valve prevents the valve opening.
- When an air start signal is given, the control valve opens and the space under the valve is vented. The air pressure acting on the top surfaces of the valve overcomes the spring force and the valve opens.
- The valve can be tested by opening the test valve. In an emergency it can be manually operated.
- The valve outlet incorporates a non return valve. A pressure gauge connection and a manual venting valve are fitted to the valve body.
Video shows a simple working of start air valve
