2. TESTS
• DESTRUCTIVE TESTS
– Tensile, Impact, Bend etc
• NON-DESTRUCTIVE TESTS
– Radiography
– Ultrasonic
– Dye Penetration
– Magnetic Particle
– Leak tests like Air test,Ammonia test etc.
– Hydrostatic test
3. WHY HYDROSTATIC TEST
• To ensure the integrity of the equipment
• To ensure the strength of the weld joints &
material
• To ensure the strength of the nozzle flange
joints
• To relieve the stresses
• Ensures safe and reliable performance
during the operational life
4. HYDRO TEST
• Good planning is essential for completion
of hydrotest in minimum possible time
•Gauges, transducer/ recorder , Sq. Bar,
Hose pipes, Pump
•Location, weight distribution, draining
•Saddles, slope, venting
•Water- quantity,quality & temperature
•Torque tightening / tensioning units
•Flanges, bolts / studs
5. HYDRO TEST
• The hydro test saddles shall be located on
shell in such a way that all circumferential
seams are free from saddle location. Long
seams if any covered by the saddle; the
corresponding location of saddle material
shall be grooved to facilitate the inspection
of weld joint under test
9. HYDRO TEST
• Carry out tightening of Nozzle / Man
way covers as per the required
torque
• Use proper tightening unit to meet the
requirement of PSI / Torque and follow
the tightening sequence as per
approved procedure for bolts / studs
• Start filling water after confirmation of
all requirements ( like venting, PPM of
water, Clearance of Job for fill up)
12. HYDRO TEST
• Ensure that the nozzles (top) are
open for air removal
• Let the water flow out of the top
nozzles so that the air is removed
• Close the nozzle & allow the water to
flow from top and confirm absence of
air bubbles
16. HYDRO TEST
• Start the pump for pressurizing the
water inside the equipment. (Selection
of pump depends on the pressure and
discharge of water from pump. Set the
output pressure of pump such that it
should not exceed hydro test pressure
for safer operation)
17. HYDRO TEST
• Ensure that minimum two pressure
gauges are attached
• The pressure gauges shall have an upper
range of 2 times the test pressure but in
no case less than 1.5 times or more than
4 times the test pressure. The transducer
shall have minimum upper range of 1.25
times the test pressure. Only calibrated
pressure gauge and transducer shall be
used. Validity of calibration shall be
verified on the calibration sticker pasted
on the pressure indicators
18. HYDRO TEST
• Increase the pressure as per the
requirement given in drawing or the
approved procedure
• During pressurizing from design
pressure to test pressure, no one
shall remain on the vessel or very
near to bolted connections on the
vessel
19. HYDRO TEST
• Hold the test pressure for minimum
30 minutes or as specified by the
drawing / specification. The test
pressure shall not get dropped
during the holding time. The vessel
connections shall not be inspected
closely for any leakage at this stage
20. HYDRO TEST
• Reduce the pressure to Design
pressure
• Check for any leakage in weld joints
and bolted joints
• If no leakage is observed,
depressurizing can be started
21. HYDRO TEST
Depressurizing :
• If cycle is specified , follow the same
• If not specified, reduce pressure
slowly by opening the square bars (at
top) such that pressure drops to zero
• Never open bottom noz./ Sq. bar
• While draining the vessel, the top vent
valve shall be kept open before
opening any nozzle at the bottom. This
is for eliminating the possible collapse
of thin shells due to vacuum created
within the test vessel
22. HYDRO TEST
• Pressure gauges once used for a
pressure test shall be recalibrated. For
this purpose, the pressure gauges
once used shall be crossed on the
calibration sticker and send to QA
