API 510 STUDY GUIDE 2026/2027 QUESTIONS AND
SOLUTIONS RATED A+
✔✔Minimum overlaps for vessel PWHT when using multiple heats - ✔✔5'
✔✔Maximum length of weld represented by 1 spot RT - ✔✔50'
✔✔Minimum allowed wall thickness at a pit - ✔✔1/2 tmin
✔✔Welding base metal temp where welding is not recommended - ✔✔< 0 F
✔✔Welding base metal temp where preheat to 60 is reccomended - ✔✔0-32
✔✔Temp range CUI on CS and low alloy - ✔✔10 - 350
✔✔UT calibration temp in comparison to metal temp - ✔✔25 degrees from metal temp
✔✔Temp range for a PT exam - ✔✔40-125
✔✔Temp where cooling water corrosion starts to significantly increase - ✔✔140
✔✔Temperature where CSS become a concern - ✔✔> 140
✔✔Special procedures for UT readings - ✔✔> 150
✔✔Temperature swings that can cause thermal fatigue - ✔✔+- 200
✔✔Most aggressive CUI temp range - ✔✔212-350
✔✔CUI affects duplex - ✔✔280-350
✔✔Minimum pre heat when preheat is substituted for PWHT - ✔✔300
✔✔Minimum preheat when local PWHT instead of full encirclement - ✔✔300
✔✔Temp for sulfidation - ✔✔500
✔✔Temper embrittlement for low chromes - ✔✔650-1100
✔✔Cat reformer creep temp - ✔✔> 900
✔✔NDE max temp for UT readings - ✔✔1000
, ✔✔Carbon steel normal PWHT temperature - ✔✔1100
✔✔Carbon steel temp of base metal to create HAZ - ✔✔> 1350
✔✔Minimum base metal temp during hydro <= 2" thick - ✔✔MDMT + 10
✔✔Minimum base metal temp during hydro > 2" thick - ✔✔MDMT + 30
✔✔Maximum temp for MT - ✔✔Manufacturer recommended
✔✔Relief device prevents pressure from rising ____ over MAWP - ✔✔10% or 3 psi.
Whichever is greater
✔✔Lethal - ✔✔Small amount when mixed or unmixed with air is dangerous to life if
inhaled
✔✔Mill under tolerance for the plate - ✔✔6% or .01" whichever is less
✔✔Set pressure tolerance of relief device over 70 psi - ✔✔3%
✔✔Overlap distance for multiple PWHT - ✔✔5 ft or 60"
✔✔Set pressure tolerance relief device below 70 psi - ✔✔2 psi
✔✔Relief device tolerance - ✔✔10% or 3 psi whichever is greater
✔✔Impact tests shall consist of how many bars - ✔✔3
✔✔Over what thickness do you have to PWHT - ✔✔1.5
✔✔Weld procedure - ✔✔WPS
✔✔Qualification of a weld procedure - ✔✔PQR
✔✔Welders qualification record - ✔✔WPQ
✔✔Document that must be prepared and maintained for each vessel/relief device -
✔✔Inspection plan
✔✔Manual that must be maintained by owner user that uses API 510 - ✔✔QA
insp/repair manual
✔✔Two docs required of relief device repair organization - ✔✔QA manual and training
SOLUTIONS RATED A+
✔✔Minimum overlaps for vessel PWHT when using multiple heats - ✔✔5'
✔✔Maximum length of weld represented by 1 spot RT - ✔✔50'
✔✔Minimum allowed wall thickness at a pit - ✔✔1/2 tmin
✔✔Welding base metal temp where welding is not recommended - ✔✔< 0 F
✔✔Welding base metal temp where preheat to 60 is reccomended - ✔✔0-32
✔✔Temp range CUI on CS and low alloy - ✔✔10 - 350
✔✔UT calibration temp in comparison to metal temp - ✔✔25 degrees from metal temp
✔✔Temp range for a PT exam - ✔✔40-125
✔✔Temp where cooling water corrosion starts to significantly increase - ✔✔140
✔✔Temperature where CSS become a concern - ✔✔> 140
✔✔Special procedures for UT readings - ✔✔> 150
✔✔Temperature swings that can cause thermal fatigue - ✔✔+- 200
✔✔Most aggressive CUI temp range - ✔✔212-350
✔✔CUI affects duplex - ✔✔280-350
✔✔Minimum pre heat when preheat is substituted for PWHT - ✔✔300
✔✔Minimum preheat when local PWHT instead of full encirclement - ✔✔300
✔✔Temp for sulfidation - ✔✔500
✔✔Temper embrittlement for low chromes - ✔✔650-1100
✔✔Cat reformer creep temp - ✔✔> 900
✔✔NDE max temp for UT readings - ✔✔1000
, ✔✔Carbon steel normal PWHT temperature - ✔✔1100
✔✔Carbon steel temp of base metal to create HAZ - ✔✔> 1350
✔✔Minimum base metal temp during hydro <= 2" thick - ✔✔MDMT + 10
✔✔Minimum base metal temp during hydro > 2" thick - ✔✔MDMT + 30
✔✔Maximum temp for MT - ✔✔Manufacturer recommended
✔✔Relief device prevents pressure from rising ____ over MAWP - ✔✔10% or 3 psi.
Whichever is greater
✔✔Lethal - ✔✔Small amount when mixed or unmixed with air is dangerous to life if
inhaled
✔✔Mill under tolerance for the plate - ✔✔6% or .01" whichever is less
✔✔Set pressure tolerance of relief device over 70 psi - ✔✔3%
✔✔Overlap distance for multiple PWHT - ✔✔5 ft or 60"
✔✔Set pressure tolerance relief device below 70 psi - ✔✔2 psi
✔✔Relief device tolerance - ✔✔10% or 3 psi whichever is greater
✔✔Impact tests shall consist of how many bars - ✔✔3
✔✔Over what thickness do you have to PWHT - ✔✔1.5
✔✔Weld procedure - ✔✔WPS
✔✔Qualification of a weld procedure - ✔✔PQR
✔✔Welders qualification record - ✔✔WPQ
✔✔Document that must be prepared and maintained for each vessel/relief device -
✔✔Inspection plan
✔✔Manual that must be maintained by owner user that uses API 510 - ✔✔QA
insp/repair manual
✔✔Two docs required of relief device repair organization - ✔✔QA manual and training
