Christmas Tree

Christmas tree

Evergreen tree, usually decorated with lights and ornaments, to celebrate the Christmas season. The use of evergreen trees, wreaths, and garlands as symbols of eternal life was common among the ancient Egyptians, Chinese, and Hebrews. The Christian symbol can be traced to a German medieval play about Adam and Eve, which included the “paradise tree,” hung with apples. The modern, decorated version was widespread among German Lutherans by the 18th century. Brought to North America by German settlers in the 17th century, it had become widespread there by the mid-19th century. It was popularized in 19th-century England by Victoria's consort, the German Prince Albert of Saxe-Coburg.

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Christmas tree

1. an evergreen tree or an imitation of one, decorated as part of Christmas celebrations

2. Austral any of various trees or shrubs flowering at Christmas and used for decoration

3. another name for pohutukawa

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Christmas tree [′kris·məs ‚trē]

(petroleum engineering)

An assembly of valves, tees, crosses, and other fittings at the wellhead, used to control oil or gas production and to give access to the well tubing.

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Christmas tree

custom originating in medieval Germany of decorating an evergreen tree at Christmas. [Christian Tradition: NCE, 552]

See : Christmas

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(hardware, jargon)

Christmas tree - A kind of EIA-232 line tester or breakout box featuring rows of blinking red and green LEDs suggestive of Christmas lights.

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Christmas Tree

control equipment installed at the casing-head of a gas or petroleum well. The casinghead connects the casing columns inserted into the well during drilling. The Christmas tree consists of a lower part—the tubing head—and an upper manifold—the Christmas tree proper. The tubing head serves as a mounting for the manifold above and as a sealing and control element between the manifold and tubing. The Christmas tree is installed on the casinghead and receives the well production.

In the USSR, two standard types of Christmas trees are manufactured: crosses and tees. Standard designs may be altered to meet specific requirements. In some cases, the well is equipped with not one but two tubing columns inserted inside the casing column, necessitating a corresponding change in the arrangement and number of fittings in the tubing head and Christmas tree.

REFERENCES

Spravochnaia kniga po dobyche nefti. Moscow, 1974.
Armatura fontannaia: Tipovye skhemy i osnovnye parametry: GOST 13846–74.