Module 3 Alkalies and Amine Treating Flashcards
Amine SCC (ACSCC) found where?
HAZ (non PwHT)
Amine SCC (ACSCC) affected material?
CS/Low alloy
Amine SCC (ACSCC) critical factors
a. type of amine
b. stress
c. temperature
Amine SCC (ACSCC) is often associate with what type of amine? and at what %?
Lean / >2%
Amine SCC (ACSCC) pure amine is \_\_\_\_\_ corrosion
not
Amine SCC (ACSCC)
appearance?
a. Amine SCC initiates on _______side (welds)
b. cracking typically ____to the weld (longitudinal or transverse)
c. could occur process side opposite external ________
a. process
b. parallel
c. attachment welds
Amine SCC (ACSCC) c. thoroughly \_\_\_\_\_\_ non-PWHT
water wash
Amine SCC (ACSCC) \_\_\_\_\_\_\_\_ effective for surface breaking cracks
a. WFMT/ACFM/ECT
Amine SCC (ACSCC) \_\_\_\_\_\_ effect to detect size cracks
b. Angle beam (SWUT/PAUT)
Amine SCC (ACSCC) \_\_(2)\_\_ may not be used/effective
PT/ RT
Carbonate SCC (ACSCC) affected material?
CS / low alloy steels affected
Carbonate SCC (ACSCC) critical factor? (3)
a.WATER/carbonate/stress
Carbonate SCC (ACSCC) what pH >\_\_\_ is an issue and what level failure typically occurs?
7.5
8-10
Carbonate SCC (ACSCC) ammonia (NH3) does what to the pH
increase
Carbonate SCC (ACSCC) carbon concertation?
> 100 ppm BUT no specific threshold
Carbonate SCC (ACSCC) does Cyanide have any effect
NO
Carbonate SCC (ACSCC) increase N2 feed does what to pH
increase PH
Carbonate SCC (ACSCC) H2S concentration?
d. H2S - no specific level of concentration
Carbonate SCC (ACSCC) where does it occur most often location? (3)
Carbonate cracking has been most prevalent in FCC unit main fractionator OVERHEAD condensing and reflux systems,
regenerator cold wall shell
PWHT
Carbonate SCC (ACSCC)
appearance?
propagate ____to the weld in the HAZ OR adjacent base metal within___”
a. parallel / 2 in.
Carbonate SCC (ACSCC) found \_\_\_\_\_away from the toe of the weld than cracks resulting from SSC or SOHIC.
further
Carbonate SCC (ACSCC)
prevention?
PWHT to what temp?
1200-1225F
Carbonate SCC (ACSCC) best mitigation?
monitor pH of SW most practical and cost-effective method