7/25/2019 File No. 7_API 936

1/8

API 936: Refractory Installation, Inspection and Testing

PART - III

IMPORTANT POINTS FROM STANDARD API 936

7/25/2019 File No. 7_API 936

2/8

IMPORTANT POINTS FROM STANDARDAPI 936

This standard provides installation quality control procedures for monolithic

refractory linings. The responsibilities of inspection personnel who monitor and

direct the quality control process are also dened in the standard.

Definitions

1. Abrasion resistance: The ability to withstand the effects of eroding particles

for an extended period without significant loss of aterial or other daage!

2. As-instae! testin": Testing of refractory aterials sapled fro the

installation to confir that they eet specified physical property standards!

3. #isc$it: A refractory piece fored within an area copletely enclosed by

the anchoring syste!

%. &o! &r$s'in" Stren"t': "&&S( A easure of a refractory#s ability to

resist failure under a copressi$e load as deterined at roo teperature afterdrying and%or firing!

). &o! *a: An insulating refractory lining syste with a etal shell teperature

less than &''() "*6'(+!

6. Dr+-o$t: The initial heating of a newly installed castable lining in which heating

rates and hold ties are controlled to safely reo$e retained water without explosi$e

spalling and to for a well distributed networ- of shrin-age crac-s in the lining!

,. Firin": The process of heating refractories to de$elop desired properties!

. $nnin": The application of onolithic refractories by eans of air placeent

guns!

9. /ot *a : A thin refractory lining syste with a etal shell teperature greater than

&''() "*6'(+!

7/25/2019 File No. 7_API 936

3/8

10. Pre-*ettin" "$nnin"(: A techni.ue used with dry gunning achines

where a sall .uantity of water is ixed into the dry refractory before charging into

the gun to reduce rebound and dust, and to ipro$e wetting of the

ceent in the gunning operation!

11!et "$nnin": Pneuatic placeent of preixed castables "including

water where flocculating agents and placeent air are added at the no//le!

Resonsibiities

1.O*ner

0! The owner shall prepare a detailed specification! The specification shall include the

following design details!

a 1ining products, thic-ness, ethod of application, and extent of co$erage!

b Anchor aterials, geoetry, layout and weld details! 2uggested color coding for

etallic anchors is pro$ided in Annex !

c 4hen used, details of etal fiber reinforceent including diensions, concentration, type,

and etallurgy!

d +uring and dry5out procedures, including constraints on dry5out heating "e!g!

design teperature liits and%or axiu differential teperatures that shall be

aintained to a$oid daaging the unit and%or coponents!

*! The owner shall pro$ide .uality re.uireents co$ering the following!

a Physical property re.uireents to be used for .ualification and installation .uality

control by specific product, installation ethod and location where the product will be

utili/ed! These re.uireents shall be in accordance with Annex + unless aended

by prior agreeent with owner!

b 2apling fre.uency as applicable for the products intended use in either

erosion ser$ice or other ser$ice!

c Re.uired lining thic-ness tolerances!

d +riteria for haer testing and the extent of crac-ing and surface $oids peritted!

3! The owner shall appro$e the engineering drawings, execution plan and dry5out

procedure prior to any installation acti$ity!

7/25/2019 File No. 7_API 936

4/8

2.&ontractor: The contractor shall prepare a detailed execution plan in accordance

with this standard and the re.uireents of the owner#s specification and .uality standards!

3.Insector: The inspector shall be responsible for the following!

a 7nsure that aterial and applicator .ualification test results are fully docuented!

b 8onitor .ualification, production wor- and dry5out "when applicable conducted by the

anufacturer"s and contractor to ensure copliance with ob

specifications and agreed5to .uality practices!

%.Insector 4$aifications

The inspector shall ha$e no coercial affiliations with the contractor or anufacturer"s!

The inspector shall be certified in accordance with API 936 Annex !

The inspector shall possess this standard, owner specifications, the proect execution

plan, and other ob specific re.uireents outlined by the owner, contractor, and%or

anufacturer! The inspector shall ha$e wor-ing -nowledge of these docuents!

Refractory materials Storage and Testing

1.Te5erat$re

Refractory aterials shall be stored at a teperature of ;'() to 0''() "&(+ to 3

7/25/2019 File No. 7_API 936

5/8

).Pre-s'i5ent Refractor+ 4$aification Testin"

Refractories to be installed by gunning, casting, or hand%ra

pac-ing shall be tested to ensure that they coply with specified physical property

re.uireents

6.For5in" of Refractor+ Test Seci5ens

)or cast installations, refractory shall be cast in the sae anner as the installation! )or

$ibration cast installations, $ibration shall be used in the foring of the test

speciens!

a )or pup cast installations, refractory shall be poured into fors!

b )or hand pac-ed installations, refractory shall be hand pac-ed!

c )or gunned installations, refractory shall be gunned to produce a large panel!

,.Aication Perio!

Refractory shall be applied within four onths of the initial .ualification tests!

.&astin" :

A oc-5up shall be prepared by each applicator, for each ixing%installation

procedure, and for each refractory being installed! Refractory cast in the oc-5up shall be

cured for 0* hours iniu prior to stripping the fors! ?eat5setting, plastic refractories

shall be allowed to air dry for a iniu of *; hours followed by o$en drying in a for

suitable for drying teperatures!

9.O8en !r+:

hold for 0* hours iniu at **'() to *3'() "0';(+ to 00'(+ in a forced air,

con$ection dryer! ?eating to this le$el shall be in accordance with anufacturer#s

recoendations! ?eat setting plastics shall be o$en dried in the fors!

10.O8en fire:heat at 3''()%h "0>'(+%h axiu to 0&''() "

7/25/2019 File No. 7_API 936

6/8

Refractor+ instaation

0! Refractory installation shall not begin until copletion of welding, postweld heat

treatent, and pressure testing!2tructural ebers, no//le extensions, and other ites

within the liits of the lining shall be wrapped with 0%< in! "3 thic-ness of a

nonabsorbent aterial to pre$ent oisture absorption fro, or bonding to, the refractory

lining! The wrapping shall be taped soothly into place!

2..Aication Te5erat$re

The teperature of the air and shell at the installation site shall be between &'() and

9'() "0'(+ and 3*(+!Teperature liits for refractory and ix water shall be in accordance

with the anufacturer#s re.uireents! In the absence of anufacturer#s ix teperatureliits, ix teperature shall be between 6'() and

7/25/2019 File No. 7_API 936

7/8

3! ric- has a nuber of disad$antages when copared to onolithic refractories!

These disad$antages include ultiple oints, coplicated anchoring, higher placeent

costs, ore difficult repair procedures, the need to aintain expensi$e in$entories of

special or scarce ites, a certain inflexibility in structural design, and higher fuel

re.uireents during anufacture!

;! Plastics are generally placed without use of fors! 4ith the exception of soe

speciali/ed tabular aluina castables, plastics ha$e a soewhat higher ser$ice liit than

castable refractories! Their ain disad$antages are greater shrin-age and crac-

de$elopent!

&! unning ixes generally ha$e low rebound loss, are predoinately used for

patching or resurfacing bric- or other refractories, ha$e a strong internal bond, and exhibit

excellent adhesion or bond to the existing refractory lining! They find extensi$e use in basic

oxygen, electric arc and open hearth furnaces, aong other applications!

6. Al-alies can effect the ser$ice life of refractory concretes! The furnace charge can gi$e

off both al-alies "B*C and the fuel sulfur copounds "2C* as $apors! These can

penetrate into the pores of the refractory concrete and react@ their reaction products cool,

solidify, and expand, soeties causing the hot face of the refractory to peel or shear away!

>! inders The binders principally used in refractory concretes are calciu aluinatesceents!

below approxiately *;'''

) "03*''

+!! )or conditions abo$e *;'''

) "03*''

+,

binder purity also becoes a design factor! enerally, the low purity binder can be

used with proper aggregates up to *>'' ) "0;'59' + below the

actual softening point of the concrete!

0'!8ost noral weight refractory concretes will ha$e less than '!& percent peranent

7/25/2019 File No. 7_API 936

8/8

linear shrin-age after firing at *''''

) "0'9''

+!