I don't know how it is nowadays, but prior to the revolution, Russian samovars were manufactured primarily in Tula. They were made by hand, with each firm producing approximately 25-30 samovars a day. There was a large concentration of samovar makers there, among whom was N. I. Goltyakova, the maker of your samovar.
The imperial eagle is simply a warrant, much like warrants granted by the British monarch to firms producing everything from tea to tires. These generally signify a commercial relationship between the manufacturer and the court, and may be stamped on products for as long as the firm supplies the court and remains in good standing. (The British counterpart to the imperial eagle is, currently, "By Appointment to Her Majesty the Queen" and the queen's coat of arms.)
The round medallions are generally awards won by the firm at trade shows and expositions.
Judging from the photo you posted, your samovar was probably made in the last quarter of the nineteenth century, and is in great condition.