Boiler Hydro Test

Boiler Hydro Test

PREREQUISITES / STATE OF THE PLANT :-
1) Boiler is completely in drained condition.
2) CW / ACW / ECW pumps in service (at least one from each)
3) Instrument air system is available.
4) Boiler fill pump (or) CEP is ready for operation.
5) MDBFP is available for service and system is lined up.
6) Feed water system is lined up to ECO inlet.
7) All HP heaters all isolated and feed water 100% bypass valve opened.
8) DM make up line is lined up.
9) Ammonia and Hydrazine dosing system is lined up.
10) Necessary clearance given by BMD (pressure parts) for filling the boiler and conducting
the Hydro test.
11) All Other clearances obtained as per protocol (Annexure-I)
12) If Howell is under permit :
Ensure that Deaerator overflow pneumatic valve and its upstream/downstream
manual valve are in closed condition. Ensure Deaerator overflow bypass MOV also

in closed condition & its electrical supply is in isolated condition.

BOILER FILLING & HYDRAULIC TEST PROCEDURE
A) Boiler lineup and filling procedure:
1. Boiler filling can be done either through the Boiler fill pump or through the MDBFP as
Per laid down procedure.
2. Get clearances from Boiler (Pr. Parts) , AHM, EMD, TMD and C&I Dept.
3. Inform DM plant about boiler filling.
4. Open all drum vents- (LEFT SIDE: B-1,B-2,B-3,B-4 RIGHT SIDE: B-5,B-6,B-7,B-8) and
Superheater vents(S11,S12,S13,S14,S22,S23,S24,S25) Superheater start up

vents(S29,S31,S30,S32).
5. Close all Boiler drains (EBD: B65 , B66 CBD:B 68,B-72,B-70,B-69,B-73,B-71 BOTTOM RING
HEADER BLOWOFF :B80,B-81), Economiser drains (E18,E19) & Superheater drains
(S78,S81,S82,S86,S87,S89,S90,S91,S84,).
6. Close boiler stop valves MSV-1 to MSV-2 AND IBV MSV-3,MSV-4,MSV-5,MSV-6.

Boiler filling through Boiler fill pump:

1. Ensure all FRS valves (FDV-13 to FDV-16) are in closed condition.
2. Ensure all BFP discharge valves (FDV-4 to FDV-6 and its IBV) are in closed condition.
3. Close manual valve in LPD station common header to IBD tank interconnection.
4. Open Boiler ring header drain MOV B86 & its isolating manual valve to LPD station and
Economiser drain valve (E19, E18) to LPD station for boiler filling.
5. Open Boiler filling valves to ring header and economizer at LPD station.
6. Start Boiler fill pump and maintain discharge pressure of 12-15 Ksc by adjusting recirculation
valve.
7. Continue boiler filling until hydrastep & Drum level transmitters show water level.
8. Stop Boiler fill pump after reaching desired level.
9. Close all boiler drain valves and economizer drain valves.
10. Close Boiler ring header drain MOV B86 & its isolating manual valve to LPD station and
Economiser drain valve (E19, E18) to LPD station for boiler filling.

Boiler filling with MDBFP:

1. Ensure de-aerator is filled either through condensate system or with boiler fill pump.
2. Ensure all PTWs are closed on MDBFP and feed water system components.
3. Ensure all SH/RH spray manual valves of all BFPs are closed.
4. Ensure Discharge valves of TDBFP-A&B are closed.
5. Close all FRS valves.
6. Start MDBFP on recirculation with minimum scoop with discharge valve closed.
7. Open MDBFP discharge valve IBV and fill feed water circuit up-to FRS with proper venting &
equalise pressure before and after MDBFP discharge valve.
8. Open MDBFP discharge valve
9. Open vent valve before Eco inlet valve(E2)
10. Open FRS Low load control valve and start filling economizer & drum.
11. Close vent valve before economizer once water is coming out of it.
12. Adjust flow through FRS to around 150TPH ( MDBFP Suction flow around 400TPH)
13. Start taking makeup water into condenser/ Deaerator @ 100 to 150 TPH. Start additional
DM make-up water pump
14. Reduce FRS control valve to minimum once water level is observed in Hydra step/drum level transmitters.
15. Maintain normal drum level
16. Total time required for Boiler filling will be around 2 Hours from start of MDBFP

Keeping the circulation system in service:

1. Ensure all PTWs on BCW pumps are cancelled.
2. Fill the boiler drum to around +100mm
3. Normalize power supplies of BCW pumps
4. Ensure local line up of cooling water system and cooling water flow is healthy
5. Ensure discharge valves of BCW pumps are open.
6. Close drum vents B-3,B-4 & B-5,B-6.
7. Flick start any one BCW pump for 5 Seconds and maintain drum level by adjusting FRS valve.
8. Allow drum level to rise again & flick start all BCW pumps one by one.
9. Later One BCW pump can be kept in service continuously. Observe and maintain drum level.
10. Remaining BCW pumps can also kept in service one by one. Keep drum slightly positive
before starting BCW pumps.
11. Ensure BCW pump parameters like current, DP & Cavity temp rise are normal.

B) Boiler Hydro Test Procedure

• Clearance for boiler filling obtained .
• Clearance obtained from Ash handling maintenance Dept regarding Bottom ash hopper and Eco hoppers.
• Clearance obtained from C&I dept regarding Drum & MS line Instrumentation.
• BCW Pumps cavity filled. BCW Pumps shall not be kept in service for hydro test.
• If Hydrotest is to carried out, before starting boiler filling the status of the following valves shall be checked as mentioned against each of them.
• SH header drain master valves : Closed

• Phosphate dosing valves at drum floor : Closed
• Boiler MS stop valve and its integral bypass valves ( MSV-1,MSV-2,MSV-3,MSV-4,MSV-5,MSV-6) : Closed
• Before boiler stop valve drain ( MSV- 101 & MS 102) & its isolating manual valve: Closed
• All SH,RH spray isolation valves at boiler side :Closed
• Discharge valves of BCWP : At least One Open
• All hydra step, level transmitter and gauge glass standpipe valves : Open
• All drum /SH spring loaded safety valves : To be gagged at 120 ksc
• All MS ERV’s & isolating valves valves(S71,71A,73,73A,72,72A,74,74A,75,75A) : Closed
• Soot blowing station isolating valves : Closed
• Drum, MS, Eco sampling line valve after E2 valve : Closed
• MS strainer drain & HP Bypass warm up line drain MSV-105, MSV-106 , BPV-101 & BPV-102 MOV & its manual v/v : Open
• CRH & HRH line drain to atmosphere : Open
• MDBFP recirculation valve pneumatic air : Isolated
• MDBFP SH AND RH spray valve : Isolated
• HP bypass spray manual isolating valve : Closed
• TDBFP-A & TDBFP-B Discharge valve & its IBV : Closed
• Aux PRDS spray manual valve from BFP Discharge Header : Closed
• Sampling line root v/v (MS,DRUM,FW) :Closed
• Bottom ring header rear side v/v (B80 , B81): Closed
• SH attemperation station cleared ( All valves cleared or manual valves closed)
• Condensate system cleared & charged
• Feed water system cleared & charged
• CEP, MDBFP P&I checks completed, Pumps started & kept in service
• HP Bypass valves & main turbine Stop valves are closed
• MS Line to PRDS valve AS-22 Kept closed. Drain before AS-22 kept open.
• MS, CRH & HRH line drains at TG zero meter are kept open
• Necessary C&I indicators and recorders are available
• Men & material removed from Boiler first and second pass
• Men & material removed from bottom ash hopper and economiser hoppers
• Boiler is filled with normal boiler filling procedure as outlined previously & close all drumdrains & Economiser drains.
• Keep drum vents , SH vents and drains open
• Slowly start raising drum level & fill the drum completely.
• Close the drum vents after ensuring water is coming out of them
• Continue drum filling and close all SH vents & drains after ensuring water is coming out of them.
• Close manual valves of Low point drain station and SH drain header going to IBD Tank.
• Continue raising drum pressure with MDBFP @ 10 KSC/minute ( up to 140KSC )
• Rate of rise of Pressure = 10 Ksc / min up to 80 % of design pressure & then 1-2 Ksc /min for balance pressure.
• Ensure MS line pressure on TG side is zero. If pressure raise observed, further tighten the valves MS-1 to MS-6.
• MS and Drum safety valves are gagged by BMD @ 140 KSC (for hydro test pressures above 180 Kg/CM2). Hold the Drum Pressure till gagging is completed.
• Continue raising Drum pressure as per requirement of BMD up to Max 220 KSC by increasing BFP Scoop gradually.
• Monitor MDBFP Thrust bearing temperature & vibrations.
• For external hydro test it is required to raise the drum pressure to 1.25 of drum design pressure i.e. 259 Ksc.
• Hold the boiler pressure at desired max value for 10 minutes. Then reduce the scoop of the
• MDBFP to 120 ksc and observe the drop in drum pressure. It should not exceed 1 ksc / min. and hold there for 5 to 10 Minutes.
• Inform BMD for removal safety valve gags. Ensure all safety valve gags are removed.
• Then slowly reduce drum pressure to 100 KSC. Inform BMD for inspection.

Boiler Checks during Hydraulic Test (To be recorded in protocol):

• Passing of MS line drains to IBD and CBD/EBD valves.
• Passing of MS SV through MS line atmospheric drains.
• Passing HP bypass valves through atmospheric drain at 0 m.
• Passing of any vent v/v in boiler side, valve glands,
• Any Leakage from Eco / WW / SH tube, any welding joints, Drum man holes etc.

C) Boiler Complete Depressurization & Draining:

• After completion of inspection, slowly reduce drum pressure by reducing MDBFP scoop to minimum. Close FRS valves & MDBFP discharge valve.
• Rate of depressurization = 1 Ksc/Min
• Open SH vents and drains & drum vents @ 3KSC
• Bring down drum level to normal value.
• Open MS line drain valves MS-101 & MS-102.
• Open Manual valve of SH drain station header to IBD Tank.
• Open Manual valve of LPD Station to IBD Tank.
• Ensure complete draining of Super heater & MS line by opening all vents & drains.
• Complete Boiler hydro test protocol after successful completion of hydro test. Note down defect for each department 
• Open CBD Root valve, sampling valves, Phosphate dozing to drum Valve.
• Normalise all other isolations done earlier as per requirement.
• Drain the boiler as per BMD requirement by opening CBD and other boiler drains.
• IF Boiler is to be drained, Stop MDBFP & Isolate power supply
• Ensure power supply isolation of all BCW Pumps, If the boiler is drained.