1. For ASME VIII-I vessels, Hydraulic test pressure is
HYDRAULIC TESTING
MAWP
For ASME VIII-I vessels,
Hydraulic test pressure is
minimum of 1.3 x vessel MAWP
UG-98

2. TEMPERATURE CORRECTION
TEST PRESSURE
TEMPERATURE CORRECTION
Allowable stress at test temp
Allowable stress at design temperature
Test P=1.3 x MAWP x
Test pressure correction is needed because the material is stronger at (ambient ) test temperature than it elevated design temperature

3. HYDROTEST VISUAL EXAMINATION
FOR SAFETY REASONS
The ASME principle is to reduce the pressure to Test Pressure/1.3 before approaching the vessel under test.

4. HYDROSTATIC TEST ON STORAGE TANKS
Tank is just filled with water under static head
Test lasts 24 HRS