procedure for condenser flood test and vacuum tightness test

7/15/2019 Procedure for Condenser Flood Test and Vacuum Tightness Test

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Station: NTPC- Simhadri BHEL Ref No.PS-DC-186-500-0016

NTPC Ref no SIM/1/TS/2/004Sheet 1 of 12

Plant area: TURBINE

PROCEDURE FOR CONDENSER FLOOD TEST AND VACUUM TIGHTNESS TEST

SLNO

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

PLANT DETAILS

OBJECTIVE

PROPOSAL

SERVICES REQUIRED

SAFETY PERECAUTIONS

EMERGENCY PROCEDURE

STATE OF THE PLANT

METHOD

COMPLETION CRITERIA





Plant area: TURBINE

PROCEDURE FOR CONDENSER FLOOD TEST AND VACUUM TIGHTNESS TEST SLNO

1.0

1.1

1.2

1.3

1.4

1.5

1.6

PLANT DETAILS:

The plant consists of condenser, Hotwell, 2 Nos, of vacuumPumps and drains and vents from different specified systems tocondenser. Vacuum system is mainly to condense steam exitingthe LP Turbine at subatmospheric pressure so that the over allefficiency of the cycle is improved. Also the condensed steam isre-cycled with out wastage. Functions of the main equipmentsystem are as given below.

Condenser : -

It is mainly to condense the steam coming out of LP turbine laststage by admitting cooling water in the tubes. The steam loose itsenthalpy to cooling water while condensing.

Hot well : -

This is to store the condensate arising out of cooling of steamand give the suction head to condensate pumps.

Vacuum Pump :-

This is to evacuate the air-vapour mixture from the condenser and create a negative pressure to improve the cycle efficiency.

Plant item completion list for mechanical, Electrical and C & I tobe prepared at site.

Signed copy of SRCC to be enclosed.

STATUS

Signatures

NTPC BHEL





Plant area: TURBINE


SLNO

2.0 OBJECTIVE:

The objective of the procedure is to check the system for air ingress points and to achieve the desired rated vacuum.

STATUS

Signatures

NTPC BHEL





Plant area: TURBINE


3.0

3.1

3.2

TESTING PROPOSAL:

The objective is achieved by carrying out the following testproposals.

STAGE – I Water Fill Test

The tightness of the system shall be established by water fill test.Under this all the equipments and systems coming in contact with

condenser are filled with DM water and leaks are noticed. Thenthe leakage points are arrested to prevent the air ingress whilevacuum is raised.

STAGE – II Vacuum Pulling

Vacuum is raised to check the tightness of the system whichwere not included in the water fill test. During this test, the partswhich were not subjected to water fill test are examined for anyair ingress and the same will be arrested after identification. Bythis, the entire system is tested thoroughly to obtain the desiredrated Vacuum for better performance of the steam cycle.

STATUS

Signatures

NTPC BHEL





Plant area: TURBINE


4.0

4.1

4.2

4.3

4.4

4.5

4.6

4.7

4.8

4.9

SERVICES REQUIRED:

Availability of DM water for water fill test.

Availability of proper illumination around the equipments in thetest area.

Availability of Condenser cooling water system.

Availability of H.T/L.T Power supply (for operating CEP, VaccumPumps)

Availability of communication facility at test area.

Availability of Man Power and T & P for leak detection andattending.

Availability of Portable fire extinguisher at test area.

Availability of dewatering pump near test area and a pit for dewatering.

Availability of flexible polythere tube for level monitoring incondenser steam space.

STATUS

Signatures

NTPC BHEL





Plant area: TURBINE


5.0

5.1

5.2

5.3

5.4

SAFETY PRECAUTIONS :

Ensure the availability of first Aid Box near the test area

Ensure that the personnel deployed to check the system leakageare provided with required safety gears, such as helmets, safetybelts etc.

Ensure proper temporary scaffolding is provided to reachcondenser neck portion and other unapproachable areaswherever required.

Ensure the test area is clean and devoid of obstruction and therequired flooring completed.

STATUS

Signatures

NTPC BHEL





Plant area: TURBINE


SLNO

6.0

6.1

6.2

6.3

6.4

6.5

EMERGENCY PROCEDURE:

The personnel for this operation shall be well aware of the layoutof this system.

They shall be in a position to use the safety devices whilesearching for leaks during testing.

Test Team should be aware of emergency steps to be taken onthe event of any accidents occurring to men and material while

conducting the test.

During the test, all precautions to be taken at local and remote toobserve the running CEP, Vacuum pump and any tend inincrease in bearing temperature or vibration should becommunicated to control room for appropriate follow up action.

Test team should be aware of operation of portable fireextinguishers.

STATUS

Signatures

NTPC BHEL





Plant area: TURBINE

PROCEDURE FOR CONDENSER FLOOD TEST AND VACUUM TIGHTNESS TESTSLNO

7.0

7.1

7.1.1

7.1.2

7.1.3

7.1.4

7.1.5

7.1.6

7.1.7

7.1.8

7.1.9

7.1.10

7.1.11

STATE OF THE PLANT:

For water fill test; The following are completed.

Erection of condenser and connected piping of vacuum systemas per recommended drawing.

The erection work in LP casing exhaust.

Removal of temporary platform, if any erected in LP casingexhaust.

The permanent hangers and supports for connected piping.

Removal of temporary supports.

Make up water line to condenser for filling the condenser steamspace.

Installation of flexible polythene tube for monitoring the water level in condenser steam space.

Locking of the jack bolts of condenser springs before startingwater fill test so as to arrest the spring action.

Locking of all the hangers of drain flash tanks and connected pipeLines in vaccum system.

Installation of level gauge glass of hot well, LP heaters and HPheaters.

Cleaning of hot well.

STATUS

Signatures

NTPC BHEL





Plant area: TURBINE


SLNO

7.1.12

7.1.13

7.2

7.2.1

7.2.2

7.2.3

7.2.4

7.2.5

7.2.6

7.2.7

7.2.8

7.2.9

Installation of level switches and level transmitters for hotwelllevel & LP Heaters & HP heaters.

The piping & tanks under vacuum system are not to be insulatedincluding at welding joints and flange joints, manholes, rootvalves, stubs etc.

For actual vacuum pulling: The following are completed

Vacuum pumps are ready for operation.

Gland seal steam exhauster fans trial run completed.

CEP trial run completed with required interlock and protections.(The list of minimum interlocks and protections to be mutuallyprepared at site).

Gland steam control valves commissioning.

Availability of mercury manometer/calibrated gauge.

Charging of cooling water to condenser water boxes.

Vacuum breaker valve commissioning.

Barring gear with interlocks & protections should be ready.

Gland sealing water lines for valves coming under vacuumsystem are completed.

STATUS

Signatures

NTPC BHEL





Plant area: TURBINE


SLNO

8.0

8.1

8.1.1

8.1.2

8.1.3

8.1.4

8.1.5

8.1.6

8.1.7

8.2

8.2.1

8.2.2

8.2.3

8.2.4

8.2.5

METHOD:

Water fill test

Start filling water in system gradually. Release the air of LPHeaters, HP Heater, Drain cooler and Gland steam condenser byopening their vent valves during filling.

Check for leakages in the system after every 1 M rise in water level.

Drain and attend leakage wherever leaks are noted.

Check the leakages upto 1 M above tube nest and maintain thislevel during this test.

Drain the system and attend all leakages.

After the completion of leak test, clean hot well and release the jack bolts of condenser springs.

Fill Hot wall up to normal level.

Vacuum Pulling

Run one CEP on recirculation.

Put machine on barring gear.

Line up seal steam supply and gland steam cooler.

Start one seal steam exhauster fan and both vacuum pumps.

After achieving about 0.2 kg/cm2 vacuum, charge seal steam toturbine glands. Downstream parameters to be maintained are:Pressure : 0.01 KSC and temp > 160oC

STATUS

Signatures

NTPC BHEL





Plant area: TURBINE


8.2.6

8.2.7

Check system for air ingress points if proper vacuum is notachieved and same shall be rectified.

Stop one vacuum pump when desired vacuum is achieved andstabilised. However, if with one vacuum pump, vacuum is notholding then check for air ingress and attend the leakages.

STATUS

Signatures

NTPC BHEL





Plant area: TURBINE


SLNO

9.0

9.1

9.2

9.3

9.4

COMPLETION CRITERIA:

Condenser Flood Test and Vacuum tightness test is completedwith following completion criteria.

Condenser Flood Test is completed after satisfactorily attendingall the identified leakages.

After achieving the required vacuum, stop both vacuum pumpsand record the rate of fall of vacuum 10 minutes. The rate of fallof vacuum should be 2 to 3 mm of Hg per minute.

After attending all the leakages, total hogging time taken for achieving full vacuum shall be noted down by running eachvacuum pump separately one by one and by running both thevacuum pumps together.

STATUS

Signatures

NTPC BHEL



PROCEDURE FOR CONDENSER FLOOD TESTAND VACUUM TIGHTNESS TEST

procedure for condenser flood test and vacuum tightness test

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