Schwing SPB 28, Руководство по эксплуатации

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APPEN D IX
PAGE 74
700Apndx.fm
S AF ETY M AN U AL
V II . W eld- On E n d s / Co u p l ing Co m parison
Metric (Single &
double wall)
Male / Female
O-Ring
(shown with clamp)
Heavy-Duty
weldends7.eps
Grooved; flange
height equal to or
less than 0.150”, cut
directly into pipe wall.
NOT ALLOWED for
concrete pumping
per ASME B30.27
Shown is a comparison among commonly used ends/couplings. No two ends shown can be joined without
the use of an adapter pipe or a special adapter clamp. Clamps and pipe strength must also be considered
when determining proper system requirements. The ratios shown in the text below represent the safety factor
from burst:working pressures.
3. Metric couplings are designed for pressures up
to 1400 PSI @ 2:1. They have 85% more contact
area than grooved couplings. The face is flat and
will not draw pipe together. Although they have a
raised edge, they are not compatible with Heavy-
Duty couplings unless a special clamp or
an
adapter pipe is used to change from one style to
the other. Metric connections are standard equip-
ment on booms because of the weight savings
compared with other styles.
2. Heavy-Duty couplings are designed for pres-
sures up to 2250 PSI @ 2:1. They have 20% more
contact area than metric couplings, and a tapered
face that draws the pipe sections together during
assembly. Both the ends and clamps weigh more
than metric style, and therefore should not be used
on booms without consulting the manufacturer.
4. Grooved couplings (lip height of 0.15” or less)
are designed for pressures only up to 750 PSI @
2:1. The recessed groove is hard to clean when
changing pipe on a job. The weld-on end fails
before the pipe because the groove is cut into the
pipe thickness, making it the weakest spot.
Grooved couplings are not recommended for con-
crete pumping applications.
1. Male/female o-ring type couplings have the
highest pressure rating of the ends commonly
used for concrete pumping. They can withstand
4350 PSI @ a 2:1 safety factor. They are self-
aligning and waterproof when used with o-rings
in good condition. Typically not used on booms
because of their weight. Pipes equipped with this
style coupling cannot be swapped end-for-end.
N OT E : A ll pressure ratings listed refer to 5-inch ( 12 5mm) diameters in
like-new condition. Other pressures would appl y to other diameters.