Reasons for blow down
1. To remove the precipitates formed as a result of chemical addition to the boiler water.
2. To remove suspended particles, dirt, foam or oil molecules from the boiler water. This is mainly done by scum valve and the procedure is known as “scumming.”
3. To reduce the density of water by reducing the water level.
4. To remove excess water in case of emergency.
Procedure for blow down .
1.Open the overboard or ship side valve first.
2.Open the blow down valve 1, this valve is a non-return valve.
3.The blow down valve adjacent to the boiler 1 should be opened fully so as to prevent cutting of the valve seat.
4.The rate of blow down is controlled by the valve 2
5.After blow down close the valve in reverse order.
6. A hot drain pipe even when all valves are closed indicates a leaking blow down valve.
1. To remove the precipitates formed as a result of chemical addition to the boiler water.
2. To remove suspended particles, dirt, foam or oil molecules from the boiler water. This is mainly done by scum valve and the procedure is known as “scumming.”
3. To reduce the density of water by reducing the water level.
4. To remove excess water in case of emergency.
Procedure for blow down .
1.Open the overboard or ship side valve first.
2.Open the blow down valve 1, this valve is a non-return valve.
3.The blow down valve adjacent to the boiler 1 should be opened fully so as to prevent cutting of the valve seat.
4.The rate of blow down is controlled by the valve 2
5.After blow down close the valve in reverse order.
6. A hot drain pipe even when all valves are closed indicates a leaking blow down valve.
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