1. STEAM BOWING PROCEDURE OF STAGE # 1
OBJECTIVE AND PRINCIPLE OF STEAM BLOWING
STEPS INVOLVED IN STEAM BLOWING ( WITH PATH DIAGRAM)
PROCEDURE OF PRE-STEP STEAM BLOWING
PROCEDURE OF MAIN STEP STEAM BLOWING
COMPLETION CRITERIAN OF STEAM BLOWING
PHOTOS OF SIPAT U # 1 STEAM BLOWING

2. PRINCIPLE OF STEAM BLOWING
OBJECTIVE
The purpose of steam line blowing is to remove pipe slag, weld bead deposits and other foreign material from the main and reheat steam systems prior to turbine operation. The cleaning is accomplished by subjecting the piping systems to heating, blowing steam and cooling cycles in sufficient number and duration until clean steam is obtained.
PRINCIPLE OF STEAM BLOWING
To ensure that sufficient cleaning forces are applied to the piping, the steam momentum during the steam blow must be equal to or greater than the steam momentum at normal maximum load condition. The Cleaning Force Ratio (CFR) is typically used to evaluate if satisfactory blow conditions are obtained.
CFR = ( vb / vmcr ) x ( Fb / Fmcr )2 > 1.00
Where vb = specific volume at steam blowing condition
vmcr = specific volume at maximum load condition
Fb = steam mass flow rate at blowing condition
Fmcr = steam mass flow rate at maximum load condition

3. STEPS OF STEAM BLOWING PRE STEP # 1
: Separator – SH - main steam line- Temporary pipe - martyr valve - tailpipe to atmosphere.
PRE STEP # 2
: Separator - main steam line- HPBP – CRH Line – CRH Isolator - martyr valve - tailpipe to atmosphere.
MAIN STEP # 1
: Separator-SH-main steam line-MSV-temporary pipe with martyr-valve-NRV-CRH-RH-HRH-IPT Stop Valve-temporary pipe-target-tailpipe to atmosphere
MAIN STEP # 2
: Separator-SH-main steam line-MSV-temporary pipe with martyr-valve­NRV-CRH-RH-HRH-LP Bypass valve-temporary pipe-tailpipe to atmosphere

4. PRE STEP PROCEDURE COMPLETION CRITERIA
Start the Boiler as per normal working principle
Raise the Seaprator Pressure to 40 Ksc
At 40 Ksc Shut all Fuel Burners in service
Stop The BRP Pump
Open The Martyr Valve
Let the pressure fall to 20 Ksc
Close The Martyr Valve
COMPLETION CRITERIA
Clean White Smoke to be observed at the Exhaust of Tail Pipe
NOTE :
CFR < 1.0 AND NO TARGET PLATE IS TO BE USED DURING THIS STEP
First Blow at every Step to be given at much reduced pressure to check the temporary piping healthiness

5. MAIN STEP PROCEDURE Start the Boiler as per normal working principle
Raise the Seaprator Pressure to 80 Ksc ( SH O/L Temp : 370 oC)
At 80 Ksc Shut all Fuel Burners in service
Stop The BRP Pump
Open The Martyr Valve
Let the pressure fall to 40 Ksc
Close The Martyr Valve
Maintain the Separator Storage Tank Level
Light The Boiler For Next Blowing
NOTE :
CFR > 1.0 AND NO TARGET PLATE IS TO BE USED DURING THIS STEP
First Blow at every Step to be given at much reduced pressure to check the temporary piping healthiness

6. COMPLETION CRITERIAN No impacts with an diameter larger than 1 mm
A Target Plate is used to access the impacts of particle during steam Blowing. Steam Blowing will be declared when
No impacts with an diameter larger than 1 mm
Not more than 4 impacts with an diameter larger than 0.5 mm
Not more than 10 impacts with an diameter of 0.2 to 0.5 mm

13. Pre Step # 1 : MS Line Steam Blowing
Martyr V/v
Martyr V/v
Final SH
Final SH
ESV
ESV
MSV
MSV
MS Line
Martyr V/v
Martyr V/v
Final SH
Final SH
ESV
ESV
MSV
CRH NRV
CRH NRV
CRH Drain Pot
CRH Drain Pot
IP SV
IP SV
HP Bypass
HP Bypass
CRH Line
HRH Line
HRH Line
RH O/L Hdr
RH O/L Hdr
LP Bypass
LP Bypass
Open
Open
Close
Close
Martyr Valve
Martyr Valve
LPBP V/ v
Steam Blow Line
Steam Blow Line
Temporary Line
Temporary Line

14. Pre Step # 2 : HPBP / CRH Line Steam Blowing
Martyr V/v
Final SH
ESV
MSV
Martyr V/v
Final SH
MS Line
ESV
MSV
CRH NRV
CRH Drain Pot
IP SV
HP Bypass
CRH Line
HRH Line
RH O/L Hdr
LP Bypass
Open
Close
Martyr Valve
Steam Blow Line
Temporary Line

15. Main Step # 1 : HRH Line Steam Blowing
Martyr V/v
Final SH
ESV
MSV
Martyr V/v
Final SH
MS Line
ESV
MSV
CRH NRV
CRH Drain Pot
IP SV
HP Bypass
CRH Line
HRH Line
RH O/L Hdr
LP Bypass
Open
Close
Martyr Valve
Steam Blow Line
Temporary Line

16. Main Step # 2 :LPBP Line Steam Blowing
Martyr V/v
Final SH
ESV
MSV
Martyr V/v
Final SH
MS Line
ESV
MSV
CRH NRV
CRH Drain Pot
IP SV
HP Bypass
CRH Line
HRH Line
RH O/L Hdr
LP Bypass
Open
Close
Martyr Valve
Steam Blow Line
Temporary Line

17. WATER CIRCULATION SYSTEM
To Separator
From Separator
From Separator
STORAGE TANK
SH D.S.H. No1
Click Here
Sample Cooler
Blow Down Tank
FLASH TANK
MIXING PIECE ZR WR
BRP
ECO MIXING LINK
SH COMMN DRAIN LINE
CRH DRAIN LINE
CHEM CLEANING SYS
BLR FILL PUMP
TO ECO
FROM FEED WATER
TO DRAIN HDR
WATER CIRCULATION SYSTEM

18. Modification # 2 Modification # 1
To D/A Floor
From Storage Tank
FLASH TANK ZR WR
Condensor
From Service Water
Condensor
Dummy
Temporary Connection
To Station Drain