How does heat affect pressure negative and positive

[cppd81]

Hello,In a substation transformer, can heat cause a negative and positive pressure. the gauge on the side list both

 

[Unolocogringo]

Yes a substation transformer is a sealed unit.
Heat will make the oil and metal in it expand causing pressure.
Cold on the other hand will cause the oil to and metal to shrink in size causing a vacuum...
imple experiment to explain.
Place a non inflated ballon on the end of a 2 litre soda bottle.
Place it in hot water and the baloon expands.(Pressure) Take it out and let it cool back to room temperature. As it cools the balook deflates.
Now place it in ice water. The baloon colapses on itself and gets sucked into the bottle. (Vacuum)

 

[tigsounds]

Hello,In a substation transformer, can heat cause a negative and positive pressure. the gauge on the side list both

Large substation transformers usually have a bottle of nitrogen and a low pressure regulator connected to them.
Heat does cause expansion pressure, and cold will pull the unit into a vacuum, thus the nitrogen, to keep the pressure positive lest moisture enter the transformer and cause contamination of the insulating/cooling oil inside.

There are relief valves to vent out excessive internal pressure as well as a sudden pressure relay to cause all circuit breakers supplying power to the transformer to trip, de-energizing the transformer as a sudden pressure is usually caused by an internal electrical fault. The sudden pressure relay is the single fastest acting relay in the entire substation or power plant bar none.

 

[JackNaylorPE]

Tig nailed it.