English to Russian Tech/Engineering Engineering (general) ASME BPVC VIII.1 UG-38

Добрый день. Кто-нибудь может объяснить что значит flued в flued opening, flued flange в соответствии с ASME BPVC VIII.1 UG-38? / Guys, could anyone please explain what "flued" in "flued opening", "flued flange" means as per ASME BPVC VIII.1 UG-38?


UG-38 FLUED OPENINGS IN SHELLS AND FORMED HEADS
(a) Flued openings in shells and formed heads made by inward or outward forming of the head plate shall meet the requirements for reinforcement in UG-37. The thickness of the flued flange shall also meet the requirements of UG-27 and/or UG-28, as applicable, where L as used in UG-28 is the minimum depth of flange as shown in Figure UG-38. The minimum thickness of the flued flange on a vessel subject to both internal and external pressure shall be the larger of the two thicknesses as determined above.
(b) The minimum depth of flange of a flued in opening exceeding 6 in. (150 mm) in any inside dimension, when not stayed by an attached pipe or flue, shall equal 3tr or (tr + 3 in.) (for SI units, tr + 75 mm), whichever is less, where tr is the required shell or head thickness. The depth of flange shall be determined by placing a straight edge across the side opposite the flued opening along the major axis and measuring from the straightedge to the edge of the flanged opening (see Figure UG-38).
(с) There is no minimum depth of flange requirement for flued out openings.

Буду благодарна за помощь. / I'll appreciate your help.