How would you cut a boiler in a line?

How would you cut a boiler in a line?

Raise steam on the boiler to be cut in,to within five pounds less than
boiler ,orboiler,already on line ,then slowly open steam stop.

The object of the lower steam in to prevent a possible priming or carry over of water.

Should the boiler be cut is higher than line pressure immediately the full load is placed upon it,with the possible result as previously states.

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