B31.3 Flashcards
What does casting quality factors Ec defined?
Ec is used for cast components not have pressure-temperature ratings
What does factors Ej defined?
weld joint quality factor /
are basic factors for straight or spiral (helical seam) welded joints for pressure containing components
How can you increase quality factors?
if additional examination is performed (NDE)
Ec=.8 (2)
- for most other metals, static castings that conform to the material specification and have been visually examined as required by MSS SP-55, Quality Standard for Steel Castings for Valves, Flanges and Fittings and Other Piping Components
- Centrifugal castings that meet specification
requirements only for chemical analysis, tensile,
hydrostatic, and flattening tests, and visual examination
max quality factor
1
For furnace but weld Ej is ? / Any additional QF allowed with NDE?
.6 / No
For ERW Ej is ? / Any additional QF allowed with NDE
.85 / No
seamless pipe Ej?
1.0
Category D Fluid Service: (4) - pressure (max) / temp limits (min/max)
1) the fluid handled is nonflammable, nontoxic, and not damaging to human tissues as defined in para. 300.2
(2) the design gage pressure does not exceed 1 035 kPa (150 psi)
(3) the design temperature is not greater than 186°C 366°F)
(4) the fluid temperature caused by anything other than atmospheric conditions is not less than −29°C
(−20°F)
Category MFluid Service:
the fluid is so highly toxic that a single exposure to a very small quantity of the fluid, caused by leakage, can produce serious irreversible harm to persons on breathing or bodily contact,
stress-relief:
uniform heating of a structure or portion thereof to a sufficient temperature below the transformation temperature range to relieve the major portion of the residual stresses, followed by uniform
cooling slowly enough to minimize development of
new residual stresses
tempering:
reheating a hardened metal to a temperature below the transformation range to improve toughness
difference between normalizing an annealing:
annealing is done in a control environment, normalizing is in ambient temp
seal weld:
a weld intended primarily to provide joint
tightness against leakage in metallic piping
theoretical throat is based on___x the leg length?
.707
spot radiograph for circumferential butt welds?
not less than one shot on one in each 20 welds for each welder or welding operator
spot radiograph for longitudinal butt welds with Ej=0.9
1 feet in each 100 feet
A slip-on flange shall be double-welded when (4) subject to (3) temp
(1) subject to severe erosion, crevice corrosion, or
cyclic loading
(2) flammable, toxic, or damaging to human tissue
(3) under severe cyclic conditions
(4) at temperatures below −101°C (−150°F)
The use of slip-on flanges should be avoided where
many large temperature cycles are expected, particularly if the flanges are not insulated.
a flange to be used under severe cyclic conditions shall be
welding neck
Bolting having not more than 207 MPa (30 ksi) specified minimum yield strength shall not be used for flanged joints (2) (class / material gaskets)
- ASME B16.5 Class 400 and higher,
2. flanged joints using metallic gaskets,
carbon steel bolting may be used with what type of class flanges and temp?
nonmetallic gaskets in flanged joints rated ASME B16.5 Class 300 and lower for bolt metal temperatures
at −29°C to 204°C (−20°F to 400°F), inclusive.
Low yield strength bolting shall not be
used for
flanged joints under severe cyclic conditions.
Tapped holes for pressure-retaining bolting in metallic piping components shall be of sufficient depth that the thread engagement
will be at least seven-eighths times the nominal thread diameter.
when can Fillet welds may be used as primary welds (2)
- to attach socket welding components and slip-on flanges.
- Fillet welds use to attached reinforcement and structural attachments, to supplement the strength or reduce stress concentration of primary
welds, and to prevent disassembly of joints.
Seal welds may be used
only to prevent leakage of threaded joints and shall
not be considered as contributing any strength to the
joints.
what should be done If a backing ring is used where the resulting crevice is detrimental (e.g., subject to corrosion, vibration, or
severe cyclic conditions)
it should be removed and the internal joint face ground smooth.
When it is impractical to remove the backing ring in such a case, consideration shall
be given to welding without backing rings or to the use of consumable inserts or removable nonmetallic backing rings.
Split backing rings shall not be used
under severe cyclic conditions.
Socket welded joints should be avoided in any service
where crevice corrosion or severe erosion may occur.
Socket welds larger than ________ shall not be
used under severe cyclic conditions.
DN 50 (NPS 2)
Where a metallic flange is bolted to a nonmetallic flange both should be
flat-faced. A full-faced gasket is preferred.
Cold spring purposes, and when is it recommend?
serves to balance the magnitude of the reaction under initial and extreme displacement conditions.
piping material of limited ductility
min gap with socket weld joint on the weld?
1/16”
A weld defect to be repaired shall be removed to
sound metal.
Alternative Heat Treatment.
Normalizing, or normalizing and tempering, or annealing may be applied in lieu of the required heat treatment after welding, bending, or forming,
what code provide guidance to PRD design and fabrication?
ASME Section VIII
Examination for Leaks. The leak test pressure shall be maintained for
at least 10 min and then all joints and connections shall be examined for leaks.
For P-Nos. 3, 4, 5A, 5B, 5C, and 15E materials, examinations shall be performed after completion of
heat treatment. However, examinations need not be repeated on welds or portions of welds that are subjected to additional heat treatments and have not been repaired by welding.
Piping in Normal Fluid Service shall be examined with what NDE and requirements?
a) Visual Examination.
1.at least 5% of fabrication
2. 100% of all completed welds,
3.100% of all completed welds, Ej, of 0.90.
4. random examination of the assembly of threaded, bolted, and other joints to satisfy the examiner, When pneumatic testing is to be performed,
all threaded, bolted, and other mechanical joints shall
be examined
b. Not less than 5% of circumferential butt and
miter groove welds shall be examined fully by random
radiography
undercut
a groove melted into the base material adjacent
to the toe or root of a weld and left unfilled by weld
material.
Examination — Elevated Temperature Fluid Service.
(a) Visual Examination.
(1) All fabrication shall be examined.
(2) All threaded, bolted, and other joints shall be examined.
(3) All piping erection shall be examined to verify dimensions and alignment.
(b) Additional Examination. The examination requirements
:
(1) Fabrication for longitudinal and spiral (helical
seam) welds in P-No. 4 and P-No. 5 materials, except
those in components made in accordance with a listed
specification, shall be examined by 100% radiographn accordance with para. 344.5, or by 100% ultrasonic
examination in accordance with para. 344.6.
(2) Socket welds and branch connection welds in PNo.
4 and P-No. 5 materials that are not radiographed or
ultrasonically examined shall be examined by magnetic particle or liquid penetrant methods in accordance
Extent of Radiography for 100%/ random and spot
a) 100% Radiography. This applies only to girth and miter groove welds and to fabricated branch connection welds
(b) Random Radiography. This applies only to girth and miter groove welds.
(c) Spot Radiography. This requires a single exposure radiograph in accordance with para. 344.5.1 at a point within a specified extent of welding. For girth, miter, and branch groove welds, the minimum requirement is
(1) for sizes ≤DN 65 (NPS 21 ∕2), a single elliptical exposure encompassing the entire weld circumference
(2) for sizes >DN 65, the lesser of 25% of the inside circumference or 152 mm (6 in.)
For longitudinal welds, the minimum requirement is 152 mm (6 in.) of weld length.
In-Process Examination type of NDE
VT
Expanded joints shall not be used
under severe
cyclic conditions.