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23 Cards in this Set
- Front
- Back
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Metal temp to be maintained above MDMT for vessels greater than 2" in thickness. |
30 deg F |
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Metal temp to be maintained above MDMT in vessels less than 2" in thickness. |
10 deg F |
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Hydro test temperature not to exceed: |
120 deg F |
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NOT an alteration |
Comparable or duplicate replacement, addition of any reinforced nozzle less than or equal to the size of existing reinforced nozzles, addition of nozzles not requiring reinforcement. |
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Temper Embrittlement |
Reduction in toughness due to metallurgical change that can occur in low alloy steels (eg 2 1/4 Cr - 1/2 Mo) as a result of long term exposure to temps 650 deg F to 1100 deg F. |
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Transition Temperature |
The temp at which a material fracture mode changes from ductile to brittle. |
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WPS |
Welding Procedure Specification |
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Hydro test pressure determination prior to 1999: |
1.5 x MAWP x (S test / S design temp) |
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Hydro test pressure determination prior to 1999: |
1.5 x MAWP x (S test / S design temp) |
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Hydro test determination 1999 and newer: |
1.3 x MAWP x (S test / S design temperature) |
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6 types of inspection |
Internal On-stream External Thickness CUI Operator surveillance |
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Maximum chloride concentration in water used to hydro test 300 Series stainless steels. |
Less than 50 ppm |
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Interval between internal or on-stream inspections and thickness measurement inspections (no RBI) when vessel remaining life is 10 years or greater. |
Not to exceed 1/2 remaining life of the vessel or 10 years whichever is less. |
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Interval between internal or on-stream inspections and thickness measurement inspections (no RBI) when vessel remaining life is less than 4 years |
Full remaining life up to a maximum of 2 years. |
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Interval for pressure vessels in non-continuous service (isolated from process and not exposed to corrosive environment). |
Number of years in actual service. |
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Interval for PSV testing and inspection. |
Frequent enough to verify devices perform reliably in particular service condition. Not to exceed: 5 years typical process service 10 years for non fouling service |
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Who can defer a PSV inspection by 6 months or 10% of the service interval (whichever is less) without approval. |
The inspector |
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Remaining life calculation |
t actual - t required / corrosion rate
t actual: actual thickness at most recent inspection t required: required thickness computed by design formulas and does not include CA. |
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Formula for minimum distance between fillet welded patches |
d= 4 x square root of Rt
(Square root is a function on the calculator)
d= min distance between toes of fillet welds R= inside radius of the vessel in inches t= the actual thickness of the underlying vessel wall
R= diameter / 2 Watch for question - if it gives you radius or diameter. |
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Formula for overlay with filler metal < MSTS (minimum specified tensile strength) of base metal. |
T fill = d x Sbase / Sfill
d = depth of base metal lost by corrosion and weld prep S base= base metal tensile strength in ksi (can use full value in formula ie: 70 ksi or 70,000 psi) Sfill= filler metal tensile strength in ksi |
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Who must approve any new nozzle installation. |
Engineer |
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When should temporary repairs be removed / replaced? |
At the next available maintenance opportunity. |
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Who develops the repair plan for equipment operating in hydrogen service at elevated temperatures? |
Engineer |
