HYDROTEST

SDP-1 V.P.SHUKLA

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

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

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

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

Sketch for Hydro test

Valves

Pressure G auge

Towards Venting pipe

Arrangem ent for O utlet P ressure G auge

Square Bar

Coupling

F ro m H y d ro te s t P u m p

T o w a rd s D ra in

V a lv e s

P re s s u re G a u g e

S q u a re B a r

C o u p lin g

A rra n g e m e n t fo r In le t P re s s u re G a u g e

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)

1

2

34

5

6 7

8

TIGHTENING SEQUENCE (with torque tightening unit)

1

1

22

3

3

4

4

5

5

6

6

7

7

8

8

TIGHTENING SEQUENCE (with tensioning unit)

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

AIR LOCK REMOVAL

1 VESSEL IN HORIZONTAL, INCLINED AT 5 DEG.

Packing

AIR LOCK REMOVAL2 WHEN INTERNALS LIKE TSRs PROVIDED INSIDE THE VESSEL

AIR LOCK REMOVAL

3 NOZZLES ON DISHEND

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)

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

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

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

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

HYDRO TESTDepressurizing :• 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

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