Chemical Cleaning

CHEMICAL CLEANING GENERAL GUIDELINE AND PROCEDURE

PREPAR PREPARED ED BY: BY:

Industrial Cleaning Services Public Company Limited

Office address: 88/8 Warisara 3 Moo 3 Pala , Ban Cang, !ayong "##3$, %ailand

CHEMICAL CLEANING GENERAL GUIDELINE AND PROCEDURE Industrial Cleaning Services Co., Ltd.

Ref. No. : Issued Date: 017/06/ 2014 Rev. 0

Page: 2

Work so! address: && Moo 3, Pala 'istrict, Ban cang, !ayong "##3$, %ailand

Po"e: 0#$ 60102% &a'. 0#$ 6010#0

SECTION 1 STAINLESS STEEL CHEMICAL CLEANING INTRODUCTION !is "rocedure covers t!e c!e#ical cleaning $"ic%ling& o' t!e stainless "i"ing eit!er "rior #aintenance

to 'a(rication

"ur"ose

()

c!e#ical

co##issioning circulation

or "ost o"erational

#et!od.

!e

"resent

s"eci*cation covers t!e "ic%ling and "assivation o' ++ "i"ing and does not reuire se"arate "assivation o' "ic%led sur'ace. !e o(-ect o' t!e c!e#ical cleaning is to re#ove all etraneous #atter, dirt, dust, grease, oil, /elding slag, loose rust, oide scales t!at #a) (e "resent on t!e "i"ing to avoid t!e conta#ination o' t!e "roduction #ainl) () /a) o' iron "ic% u". !e c!e#ical cleaning is reuired to ac!ieve "roduct ualit). !is "rocedure s"eci*es t!e #et!od o' cleaning and "assivation o' internal sur'aces o' ++ "i"ing (ased on use o' acid #iture o' nitric acid and !)dro0uoric acid "rior to ta%ing in service 'or t!e *rst ti#e a'ter installation or 'a(rication.

WORKING PROCEDURE STEP 01 - WATER FLUSHING & LEAK TEST: !e circuit $loo"& s!all (e c!ec%ed /it! circulation o' /ater to c!ec% tig!tness. An) lea%age i' o(served s!all (e attended and tig!tened. a& 1ill u" /ater to an% (& +tart /ater circulation 2 3ater an% 45 Pu#" 45 Pi"ing s)ste# 45 3ater an%



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c& +to" /ater circulation i' line !ave not lea% and read) to use c!e#ical circulation

STEP 02 - ALKALINE CLEANING !e "ur"ose o' al%aline cleaning is to re#ove dust, dirt, oil, grease and ot!er organic #atter inside t!e "i"ing s)ste#.

Chemic! C!e"i"# A#e"$ : a. IC+ 667 +ur'actant 6.8 9 6.:; vol (. NaOH 6.:; Reaction Phenomenon:

H%'(c')(" * ICS 00+ ,ROC2H./"OH CH% * ROC2H./"OH

ROC2H./"CH% * H2O :



H%'(c')(" 'em(3!

a& Circulate degreaser c!e#ical $+odiu# H)droide <=8; > IC+ 667 sur'actant 6.8=6.?;& in order to re#ove 'at, grease, /elding slag, and ot!er dirt inside t!e "i"e. (& Regularl) c!ec% t!e tur(idit) content ever) <6 #inutes, c& +to" t!e circulation i' t!e tur(idit) content s!o/ sta(le value at least @ ti#es. Esti#ated ti#e 'or t!is ste" is < !our.

@.< Drain t!e al%aline solution, and t!en *ll /it! 'res! /ater and circulate. !is o"eration o' rinsing /it! /ater s!ould (e continued till "H o' /ater at t!e inlet and outlet ends are sa#e. @.8 Circulate acid cleaner c!e#ical $HNO@ :; > H8+O? <;& in order to re#ove re#aining iron conta#ination and #ild scale inside t!e "i"e. Regularl) c!ec% t!e tur(idit) and iron content ever) <: #inutes, sto"



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t!e circulation i' t!e iron content s!o/ sta(le value at least @ ti#es. Esti#ated ti#e 'or t!is ste" is 8 !our. @.@ Drain t!e acid solution, and t!en *ll /it! 'res! /ater and circulate. !is o"eration o' rinsing /it! /ater s!ould (e continued till "H o' /ater at t!e inlet and outlet ends are sa#e. $notes2 t!e acid /aste s!ould (e neutralied "rior to dis"osal& @.? 1inall), dr) t!e circuit () "assing clean dr) instru#ent air. NO()*: 1. (e a+ove !ick,i"g !rocedure i"c,udes !assivatio" a"d does "ot re-uire se!arate !assivatio" of !ick,ed surface. 2. (e ceica,, c,ea"ed a"d dried !i!i"g sa,, "ot +e take" i"to o!eratio" iti" 72 ours after te fi"a, dri"g o!eratio" is co!,eted.

(lo)cart o* Cemical Cleaning



Page: 



Page: 6

SECTION 2 CAR4ON STEEL CHEMICAL CLEANING INTRODUCTION !is "rocedure covers t!e c!e#ical cleaning $"ic%ling& o' t!e car(on steel "i"ing or tu(ing eit!er "rior to 'a(rication co##issioning or "ost o"erational #aintenance "ur"ose () c!e#ical circulation #et!od. !e o(-ect o' c!e#ical cleaning o' "ost o"erational "i"ing s)ste#s is to re#ove oil, grease and ot!er organic #atter, and #ostl) include corrosion "roducts, #ineral scale, sludge, or "rocess conta#inants, in an) co#(ination. !e result o' t!is cleaning is t!at t!e #etal sur'aces are co#"letel) clean, dr) and in t!e "assive state /it!out signs o' corrosion. !e c!e#ical cleaning o' t!e stea# generators consist o' t!e 'ollo/ing2

WORKING PROCEDURE STEP 01 - WATER FLUSHING & LEAK TEST: a. 1ill u" /ater to an% (. +tart /ater circulation 2 3ater an% 45 Pu#" 45 Pi"ing s)ste# 45 3ater an% c. +to" /ater circulation i' line !ave not lea% and read) to use c!e#ical circulation

STEP 02 - ALKALINE CLEANING !e "ur"ose o' al%aline cleaning is to re#ove dust, dirt, oil, grease and ot!er organic #atter inside t!e "i"ing s)ste#.



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O5e'$i"# c("i$i(" : a. Pressure

2 At#os"!eric

(. e#"erature

2 I' "ossi(le, convenientl) "i"ing s)ste#

/ater te#"erature s!ould (e %e"t 'ro# B6C to 6C

Chemic! C!e"i"# A#e"$ : a. IC+ 667 +ur'actant 6.8 9 6.:; vol (. NaOH 6.:; Reaction Phenomenon:

H%'(c')(" * ICS 00+ ,ROC2H./"OH CH% * ROC2H./"OH

ROC2H./"CH% * H2O



:

H%'(c')(" 'em(3!

P'(ce6'e : a. In-ect IC+ 667 'ro# c!e#ical #iing tan%. (. Heat=u" "i"ing s)ste# /ater to a""roi#atel) B6C to 6C c. C!ec% /ater anal)sis $ur(idit)& ever) !our. d. +to" al%ali cleaning i' tur(idit) anal)sis s!o/ sta(le trend. e. 1ill u" ne/ /ater in t!e s)ste# and circulate until /ater clear

STEP 07 - ACID CLEANING !e #ain "ur"oses o' t!e acid cleaning are re#oval o' #ill scale and iron oide t!at de"osited inside t!e tu(e "i"ing s)ste# during o"erational "eriod.

Ref. No. :

CHEMICAL CLEANING

Issued Date: 017/06/ 2014

GENERAL GUIDELINE AND PROCEDURE Industrial Cleaning Services Co., Ltd.

Rev. 0

Page: $

O5e'$i"# c("i$i(" : a. Pressure

2 At#os"!eric

(. e#"erature

2 I' "ossi(le, convenientl) "i"ing s)ste#

/ater te#"erature s!ould (e %e"t 'ro# :6C to B6C

Chemic! C!e"i"# A#e"$ : a. HCL : 9 <6; vol. solution (. IC+ 68C $acid in!i(itor& < 2 <66 o' HCL @8; Reaction Phenomenon:

8HC! * Fe2O7

2FeC!7 * 7H2O



2HC! * CCO 7

CC!2 * H2O * CO2



: R69$ 'em(3! :

C!ci6m

9c!e

'em(3! M#CO7 * 2HCL

M#C!2 * CO2 * H2O



:

M#"e9i6m

9c!e 'em(3!

P'(ce6'e : a.

1ill u" /ater into "i"ing s)ste# s)ste#

(.

1lus!ed /ater until /ater clear

c.

Dose IC+ 68C $acid in!i(itor& as acid in!i(itor in order to "revent so#e corrosion on #etal sur'ace 'ro# acid.

d.

+lo/l) dose HCL into circulating tan% to dilute /it! /ater and t!en 'eed into "i"ing s)ste# s)ste# () using "u#" and %ee" circulate

e.

Maintain "H  @ during circulation.

'.

Carr) on circulation t!e c!e#ical solution 'or F 9 7 !r


g.


Page: %

C!ec% /ater anal)sis $1e8>, ur(idit)& ever) 8 !our. I' 1e8> or tur(idit) tendenc) sta(le at least 8 sa#"le t!en drain all solution

!.

Drain to ditc! a'ter neutraliation until "H 4 F = 7

STEP 0.  NEUTRALI;ATION AND PH CONTROL O5e'$i"# c("i$i(" : o

o

Pressure

2 At#os"!eric

e#"erature

2 A#(ient

Chemic! C!e"i"# A#e"$ : o

NaOH 9 control "H until 7=

P'(ce6'e : a. Add t!e NaOH to t!e s)ste# graduall) until t!e "H raise to  9 .:, (ut not eceed <6 (e'ore entering "assivation ste" (. Maintain t!e circulation 'or at least < !our to ensure t!e "H  9 .: o' t!e s)ste# !ave uni'or#l) esta(lis!ed.

STEP 0< - PASSI=ATION !e neutraliing treat#ent is carried out to sta(ilie t!e #etallic sur'aces o' a s)ste# a'ter acid cleaning and 'or "reventing t!e corrosion until t!e s)ste# start=u". Es"eciall), t!e rust "revention o' car(on steel reuires sucient cares (ecause t!e sur'ace (eco#es ver) active a'ter t!e acid cleaning.

Chemic! :

CHEMICAL CLEANING GENERAL GUIDELINE AND PROCEDURE Industrial Cleaning Services Co., Ltd. o

H)draine 6.6:;

o

NaOH 9 control "H  9 .:


Page: 10

Reaction Phenomenon:

N2H. * 8Fe2O7 #e"$ N2H. * O2

.Fe7O. * 2H2O * N2

:



2H2O * N2



P99i3i>i"#

: O%#e" 9c3e"#e'

P'(ce6'e : a.

1ill u" /ater in t!e s)ste# and circulate

(.

Dose o' +odiu# !)droide :6; to t!e circulation tan% slo/l).

c.

Circulate until "H o' /ater circulation is #ore t!an  t!en sto" dose NaOH.

d.

Dose o' !)draine to c!e#ical #iing tan% and start circulate

e.

Carr) on Circulate 'or a(out ? =7 Hours

'.

Drain t!e /ater solution and "assivation *nis!ed.

STEP 08  DR?ING a.

1inall), dr) t!e s)ste# () (lo/ing /it! nitrogen

(.

C!ec% o)gen content inside t!e tu(e regularl)

c.

+to" t!e nitrogen (lo/ing a'ter o)gen content reac!es 6.:;, !old t!e nitrogen inside /it! "ressure 6.: (arg.



Page: 11

Figure 1. Flowchart of carbon steel chemical cleaning

Table 1. Job quality plan of carbon steel chemical cleaning N (

P'(ce99

Chemic! 69e

C("i$i(" C("$'(!

Me96'i"#

E" 5(i"$ c'i$e'i

Rem'@


Tem5

< 8

Lea% test Al%aline cleaning

De#in /ater IC+ 667 6.8;

a#(ie nt a#(ie nt

Time h(6 '/

7

NaOH 6.:; @

Acid Pic%ling

HCL :=<6; in!i(itor < 2 <66 HCL

I$em

"H

<8

"H

an) ti#e ever) !our

ever) !our

ur(idit) Iron content

?

Neutraliation

NaOH

:

Passivation

H)draine 6.6:;

F

Dr)

"lant air

1

FLOW DIAGRAM

a#(ie nt a#(ie nt a#(ie nt

8

"H

<8

"H

<8

Nitrogen

Issued Date: 017/06/ 2014 Rev. 0

Page: 12

F'e6e" c%

ur(idit) a#(ie nt

Ref. No. :

ever) !our ever) !our ever) !our

No lea%age "H <6=
add #ore c!e#ical i' "H decrease

"H <=8 ur(idit) sta(le at least 8 ti#e Iron contect sta(le at least 8 ti#e

add #ore c!e#ical i' "H increase

"H =<6 "H =<6 O8 content  6.:;

Chemical Cleaning

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