Hydrotest Preparation

7/30/2019 Hydrotest Preparation

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HYDROTEST


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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


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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 nozzleflange joints

To relieve the stresses

Ensures safe and reliable performance

during the operational life


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HYDRO TEST

Good planning is essential for completionof hydrotest in minimum possible time

Gauges, transducer/ recorder , Sq. Bar,

Hose pipes, PumpLocation, weight distribution, draining

Saddles, slope, venting

Water- quantity,quality & temperature

Torque tightening / tensioning units

Flanges, bolts / studs


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HYDRO TEST

The hydro test saddles shall be located onshell 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


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Sketch for Hydro test


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Valves

Pressure Gauge

Towards Venting pipe

Arrangement for Outlet Pressure Gauge

Square Bar

Coupling


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From HydrotestPump

Towards Drain

Valves

Pressure Gauge

Square Bar

Coupling

Arrangement for Inlet Pressure Gauge


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HYDRO TEST

Carry out tightening of Nozzle / Manway covers as per the required

torque

Use proper tightening unit to meet therequirement 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)


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1

2

34

5

6 7

8

TIGHTENING SEQUENCE(with torque tightening unit)


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1

1

22

3

3

4

4

5

5

6

6

7

7

8

8

TIGHTENING SEQUENCE(with tensioning unit)


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HYDRO TEST

Ensure that the nozzles (top) are

open for air removal

Let the water flow out of the topnozzles so that the air is removed

Close the nozzle & allow the water to

flow from top and confirm absence ofair bubbles


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AIR LOCK REMOVAL

1 VESSEL IN HORIZONTAL, INCLINED AT 5 DEG.

Packing


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AIR LOCK REMOVAL2 WHEN INTERNALS LIKE TSRs PROVIDED INSIDE THE VESSEL


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AIR LOCK REMOVAL

3 NOZZLES ON DISHEND


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HYDRO TEST

Start the pump for pressurizing thewater inside the equipment. (Selectionof pump depends on the pressure and

discharge of water from pump. Set theoutput pressure of pump such that itshould not exceed hydro test pressurefor safer operation)


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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 than4 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 beused. Validity of calibration shall be

verified on the calibration sticker pasted

on the pressure indicators


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HYDRO TEST

Increase the pressure as per therequirement given in drawing or the

approved procedure

During pressurizing from designpressure to test pressure, no one

shall remain on the vessel or very

near to bolted connections on the

vessel


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HYDRO TEST

Hold the test pressure for minimum30 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


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HYDRO TEST

Reduce the pressure to Designpressure

Check for any leakage in weld joints

and bolted joints If no leakage is observed,

depressurizing can be started


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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 Neveropen bottom noz./ Sq. bar

While draining the vessel, the top vent

valve shall be kept open beforeopening any nozzle at the bottom. Thisis for eliminating the possible collapseof thin shells due to vacuum created

within the test vessel


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HYDRO TEST

Pressure gauges once used for apressure test shall be recalibrated. Forthis purpose, the pressure gaugesonce used shall be crossed on the

calibration sticker and send to QA

Documents

Hydrotest Preparation