Boiler gauge glass blow through procedure

What are boiler gauge glass blow through procedure ?

In this Article,I have discuss boiler gauge glass blow through procedure.

Let us start

There must be two independent means of determining the water level, one of which must be a direct reading gauge glass.

The other is usually a remote reading gauge in the control room which should regularly be compared with the boiler gauge glass.

Boiler gauge glass blow through procedure

1. Shut steam and water cocks than open the drain cock.
2. After draining water from the sight glass, there is nothing come out, both steam and water cocks are good in order.
3. Open the steam cock side, blow out the steam.
4. Close the steam cock side, the steam connection is clear.
5. Open the water cock side, blow out the water.
6. Close the water cock side, the water connection is clear.
7. Close the drain cock.
8. Open the water cock, water should then gradually come rise up to the top of the gauge   glass.
9. Open the steam cock, the water in the glass should fall to the level of the water in the boiler.

Boiler gauge glass blow through procedure

Explanation with Image

1. Close off cocks ‘S’ and ‘W’ and open drain ‘D’. Make sure both water and steam cocks are holding.
2. Open cock ‘W’ and blow through. Make sure that water is coming out and cock ‘W’ is clear. Close water cock.
3. Open cock ‘S’ and blow through. Make sure that steam is coming out and cock ‘S’ is clear. Close steam cock.
4. Close drain ‘D’.
5. Open water cock ‘W’ and check water level rises in the glass.
6. Open steam cock ‘S’ for showing boiler water level

The glasses should be kept clean. The glands should be nipped up at the first sign of leakage as the chemicals in the boiler water will leave a deposit on the glass.

The glasses should have protective glass shields around them and be properly illuminated.

Why need to blow down the boiler water ?

• Boiler blow down is made to reduce the density of salt and to remove the dissolved and suspended solids, also the floating solid impurities in the boiler system.

• If there are not removed from the boiler water system, foaming, priming, corrosion will occur in the boiler steam space and feed water system.

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