Английский для сварщиков. Гричин С.В. - 127 стр.

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127
utilizing a single pass. With advanced digital welding systems this is possible
up to a wall-thickness of 4 mm, and with welding systems with lower
performance capabilities (limited levels, no pulse-synchronized cold-wire-
feeding), up to 3 mm.
Joint preparation is simple but requires high quality with an exact
90\'b0 angle to the tube/pipe axis; a high quality saw cut is usually enough.
Of course, the joints should be deburred and cleaned out of corrosion, oil,
tinder, etc. With appropriate quality-demands, this should be even obvious
for manual welds! The tube joints will be then fit together without any visible
gap. This can be done with small autogenous tack-welds or with internal or
external clamping fixtures. For larger wall-thickness it is necessary to bevel
the weld-joints, far as possible in a U-shape. Since a very precise and
uniform root pass is important, a weld joint is prepared with an. I.D. related
and fixed bevelling-machine. Manual grinding or the use of bevelling saw
blades is not precise enough for repeatable welding results. Because an
Orbital-Welding job usually requires a lot in time and money, the Orbital-
multi-pass-welding is not used very often and only where it is strictly
recommended on quality reasons. A good qualified manual welder will, in
most cases, be faster than an Orbital-welding-system. Additionally, an
Orbital-system for multi-pass welds will be much more expensive and even
more complicated than a system without this option.
Visual inspections of the weld-seam clone can never be sufficient as
the sole criterion. Other quality controls, such as, corrosion, consistency,
mechanical strength must also be considered. Also, allowed tolerances in
contents of alloys on specific materials, such as sulphur content, can result in
significantly different welding results, even when the material code is the
same. Usually, you can expect that stainless steel materials up to 3 mm wall-
thickness can be done without filler-wire. For higher wall-thickness
applications, you have to decide on a case-by-case basis. In some
eventualities even carbon steel can be done without filler-material, although
it's even recommended on the thinner wall-thickness to use filler-wire in any
way.
After reading activity
Find the English equivalents in the text for the following word combinations:
противоречить законам физики, обращаться вокруг обрабатываемой
детали, иметь первостепенное значение, контроль сварочной ванны,
красивый внешний вид сварного шва, гладкий и ровный проход при
заварке корня шва, шлифовка вручную, приемлемый допуск,

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