API 570 Chap 8 Flashcards
ASME 31.3 is written for
design and construction of piping systems.
design, welding, examination, and materials also can be applied in the (4)
inspection, rerating, repair, and alteration of operating piping systems.
When ASME B31.3 cannot be followed because of its new construction coverage the piping engineer or inspector shall be guided by
API 570 in lieu of strict conformity
to ASME B31.3.
All repair and alteration work shall be done by a ______ and shall be authorized by the _______
repair organization / inspector prior to its commencement
The inspector will designate any inspection hold points required during _____
the repair or alteration sequence.
All proposed methods of design, execution, materials, welding procedures, examination, and testing shall be approved by the (2)
inspector or by the piping engineer
approval of on-stream welding is required from
owner/user
Welding repairs of cracks that occurred in-service should not be attempted without prior consultation with the piping engineer in order to
identify and correct the cause of the cracking.
The inspector shall approve all repair and alteration work at …..
designated hold points and after the repairs and alterations have been satisfactorily completed in accordance with the requirements of API 570
The design of temporary enclosures and repairs shall be approved
by the piping engineer.
Longitudinal cracks shall not be repaired with a sleeve unless
the piping engineer has determined that cracks would not be expected to propagate from under the sleeve.
what are consider temporary repairs? (3)
- on-stream, a full encirclement welded split sleeve
- box-type enclosure
- fillet patch
when can a temporary repair may be made by fillet welding a properly designed split coupling or plate patch over the pitted or locally thinned area (2)
If the repair area is localized and the SMYS (Specified Minimum Yield Strength) of the pipe is not more than 40,000 psi (275,800 kPa), and a Fitness-for-Service analysis shows it is acceptable
A fillet-welded patch shall not be installed
on top of an existing fillet-welded patch.
when installing a fillet-welded patch adjacent to an existing fillet-welded patch, the minimum distance between the toe of the fillet weld shall not be less than
d = 4 (Rt)^.5
d is the minimum distance between the toes of fillet welds of adjacent fillet weld attachments, in inches
(millimeters);
R is the inside radius in inches (millimeters);
t is the minimum required thickness of the fillet-welded patch in inches (millimeters).
Temporary repairs should be removed and replaced with a suitable permanent repair at the next available maintenance opportunity. Temporary repairs may remain in place for a longer period of time only if approved and documented by who?
piping engineer.
Any leak in a Class 1 service or where a risk ranking is determined to be high, shall be first reviewed
by a piping engineer to determine if the work can be safely performed while the system remains on stream.
For minor leaks and thinning below Tmin, properly designed enclosures may be welded over the leak or thin piping while the piping system is in-service provided…..
the inspector is satisfied that adequate thickness remains in the actual location of the proposed weld and HAZ
Permanent repairs types?(2)
- flush/insert patches
2. overlay/metal
steps to perform overlay/metal build up? (2 steps)
Surface irregularities and contamination shall be removed and Appropriate NDE methods shall be applied afterwards
Insert patches (flush patches) may be used to repair damaged or corroded areas if the following requirements are met: (3)
a) full-penetration groove welds are provided;
b) for Class 1 and Class 2 piping systems, the welds shall be 100 % radiographed or ultrasonically tested
c) patches may be any shape but shall have rounded corners [1 in. (25 mm) minimum radius]
injection fittings on valves to seal fugitive (LDAR) emissions from valve stem seal are consider as temp repairs? (Y/N)
No, they are not considered to be temporary repairs. Their removal or valve replacement is at the discretion of the owner operator
Temporary repairs of locally thinned sections or circumferential linear defects may be made on-stream by installing a
properly designed and applied enclosure (e.g. bolted clamp, nonmetallic composite wrap, metallic and epoxy wraps, or other non-welded applied temporary repair).
Temp repairs design shall consider what type of loads?
of axial thrust loads of the piping