how long can a 500 MVA transformer remain in a nitrogen-filled port for shipment in an aggressive en

[ukprofessor]

how long can a 500 MVA transformer remain in a nitrogen-filled port for shipment in an aggressive environment with saltpeter. ? The insulating paper is deteriorating, which should be impregnated with oil in its normal condition.?

 

[argotier]

Weird... I thought I had already answered to this thread...

Here it goes again:

Usual storage time for N2 filled transformer is around 3~6 months, depending on the manufacturer's instruction (which you should always refer to first).

For longer periods it is recommended to fill with enough oil to cover the windings and leave a N2 space with positive pressure.

As for the tank itself, it will depend on it's surface protection (painting). If it's ISO C5-M or CX you are lucky and it won't be a problem the salty environment.

 

[prc]

Manufacturers recommend a maximum storage of 6 months with gas filling (dry air or nitrogen) The reason is chances of moisture getting inside through gaskets. There were several such incidents from field. Long dry storage also dry out paper of oil and will require more time for oil reimpregnation.
While keeping under oil, ensure a silica gel dehydrating breather over the oil. Remember oil will expand by 0.8 % of its volume for every 10C increase in ambient temperature. Hence sufficient gas space to be kept over the oil level in tank

 

[LittleInch]

Argotier,

You probably did answer it. For some reason a few new posters have just copied questions from the past, never respond and it's not clear why they do it.

If you see s post you've answered before(usually word for word copies), look at the OP and if it's the first ever post, think before repeating the answer.[pre][/pre]

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.