Precedure Rubber Lining 73v10

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RL-44-08 REV.0

i

pROJECT KOT JOB

No.

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Page 1 of 6

Bangpain Cogen.Project

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:

ORDERNO. VENDER. NO. i RT--++-OS --------ii

KURIYAMA-OHJI (THAILAND) LTD. Amata City Industrial Estate, 7/113 Moo 4 Mabyangpom Pluakdaeng, Rayong 21 140, Thailand ( TEL) + 6638-9s6-206, -208

(FAX)+6628-9s6-207

REVISION SHEET No.

iO

DATE

;tntencuzotz

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Messrs :German-Thai Boiler Engineering Co.,Ltd.

RUB BE R LIIYI]VG PRO CED URE

OF HARD IVATURAL R(IBBER FOR

EQUIPME]YT& PIPILYG DISTRBUTION

TOTAL 6 SHEETS WCOVER

Customer

REV

I

DATE

PAGE

DESCRIPTION

KURIYAMA-OHJI (THAILAND) LTD.

APPROVAL

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CHECKED BY

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RL-44-08 REV.0

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Page 2 of 6

This procedure covers Hard Natural Rubber lining work for equipment & Piping.

1.

LINING MATERIAL

Material

: Hard Natural Rubber

Thickness

:5.0mm (+I5

OHJI-HARD E-7 (AUTOCLAVE CURTNG rypE) OHJI-HARD E-Is (EXHAUST STEAM CURING TYPE)

l-0%)

) WORIilNG LOCATION KURIYAMA- OHJI(THAILAND)

3. LINING APPLICATION 1)

PROCEDURE

Substrate inspection before lining Substrate shall be checked for appearance, welded zone and flatness. Corners and welded zone shall chiefly be inspected to confirm that it is proper for lining work. Make sure that the welded zone is free from any pinhole, sharp chamfer and undercut etc.

2) Blasting A11 surfaces to be lined shall be grid blasted in accordance with ISO 8501-1 Sa 2.5 (SSPC-SP-10) or over to ensure that the surface is clean and free from rusts and scales. 3) Adhesive coating Adhesive shall be applied on the substrate evenly.

4)

Application of rubber sheet Rubber sheet shall be checked appearance on the cutting table. It shall be cut slantwise with using soldering, knife, electric cutter or hand cutter etc. It shall be applied rubber cement. It shall be pressed to steel substrate sufficiently with hand rollers as to leave any an under the sheet.

Rubber Lining (t) Substrate

OVERLAP BEVEL T

5)

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of

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Curing Curing shall be carried out by exhaust steam in accordance with the curing conditions of Ohji standard. (Attached Chart of Autoclave & Exhaust Steam Cure)

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RL-44-08_REV.0

Page 3

4. INSPECTION 1)

Appearance Rubber lined surface shall be inspected in visually at bright place with sufficient light, and shall be free from the following defects.

(a) Mechanical damages (b) Separation (c) Blister (d) Lack of adhesion (e) Smoothness on flange surface

2)

Pinhole test Pinhole tester shall be used for the pinhole test. A pole of its secondary side shall be scanned the entire surface of rubber lining since applying the high voltage (shown in Table-l). Whether the pinhole does exist shall be examined by discharging the sparks or sounding abuzzer on the pinhole tester. Any pinhole shall not remain to the products.

If the moist, rust or scrap irons stain the surface of the rubber lining, pinhole. Hence, the pinhole test shall be gives on the clean surface.

it may cause suspected

Since applying excessively high voltage or applying voltage for a long time can cause the rubber to be damaged, it is important to select the designated voltage, and not to apply the voltage at one

point for a long time. Table-l Fixed voltase of the pinhole test Types

of

Pinhole tester Checked by

Direct, low frequency current

Voltmeter Test voltage

OHJI-HARD E-7 of OHJI-HARD E-l5

3,000V per mmTHICKNESS (Max 15kV)

Notes : The pinhole test shall be completely different from insulation tolerance

test.

Therefore, inspection with unnecessary high voltage shall not be recommended.

RL-44-08_REV.0

3)

E-7 : 75D E-15 : 70D

+71-7

+10/-10

Thickness inspection The rubber thickness shall be measured by the use of micro tester, or electromagnetic thickness tester.

Tolerance

5.

:

5.0mm (+15 I -0 %)

RBPAIRING In case that a faulty portion will be found, it shall be repaired as follows.

1) 2) 3) 4) 5)

6) 7)

Page 4 of 6

Hardness test The inspection shall be given to make sure if the products are properly vulcanized. The test piece for hardness shall be vulcanized with the product. The product and the test sample shall be measured by D type of hardness tester. The actual hardness shall be inspected with test piece at 23"C(+21-2) .

OHJI-HARD OHJI-HARD

4)

I

The defects shall be cut off. It shall be buffed with grinder. It shall be cleaned with solvent. It shall be applied adhesive. The repairing rubber sheet shall be applied to the coated surface not to leave any air underthe sheet. It shall be cured. After curing, it shall be inspected again.