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.