2 FRP LINING.pdf

COMPANY STANDARD PROCEDURE FOR FIBER REINFORCED EPOXY/FIBER REINFORCED POLYESTER LINING 1.0 SCOPE This Procedure covers the minimum requirements for lining material specifications, application procedures, inspection and testing requirements of FRE/FRP lining of pipelines/valves/exchangers/vessels etc. 2.0 MATERIAL M ATERIALS S Fibre Reinforced Epoxy (FRE) lining consists of epoxy resin mixed with suitable hardener and a fibre glass mat. Fibre Reinforced Polyester (FRP) lining consists of unsaturated polyester resin mixed with suitable catalyst, accelerator and a fibre glass mat. 2.1 EPOXY RESIN AND HARDENER The epoxy resin and hardener shall conform to the specifications given in Anexure I. 2.2 UNSATURATED POLYESTER RESIN, CATALYST AND ACCELERATOR The polyester resin, catalyst and accelerator shall conform to the specifications given in Annexure II. 2.3 FIBRE GLASS MAT The fibre glass reinforcing mat shall conform to the specifications given in Annexure III. 3.0 LOCATION/TYPE OF LINING-TYPICAL RECOMMENDATIONS LOCATION

THICKNESS

TYPE OF LINING

i External surface of pipeline running underground in sleeves.

3 mm

FRP

ii C.S. Valves in salt water service.

3 mm

FRE

iii C.S. Channel box/ cover of coolers in salt water service.

3 mm

FRE

iv Any other contoured surface previously lined or to be lined as per Inspection's recommendation.

Original thk / FRRE/FRP as as existing / as recommended. recommended

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v Internal of vessel / storage tank for protection from corrosion where recommended.

3 mm to 5 mm (as recommended)

FRE

3 mm

FRP

vi External of vessel/ storage tank.

4.0 APPLICATION The job shall be performed in the following order: (For inspection refer 5.0) i. Surface preparation. ii. Preparation of resin mixture. iii. Application of first coat of resin mixture. iv. Wrapping of chopped strand fibre glass mat. v. Application of final coat of resin mixture. vi. Curing. 4.1 SURFACE PREPARATION The prerequisite for good adhesion of a lining is cleanliness and roughness of the surface. The surface to be coated shall be shotblasted to remove mill scale and rust, existing paint and to expose the bare metal surface. (Recommended Surface cleaning to Swedish Standard SIS-05-5900 with blasting to Sa 2 finish, equivalent to SSPC-SP6-63. 4.2 PREPARATION OF RESIN MIXTURE The resin mixture shall be prepared just before application. EPOXY RESIN The epoxy resin system shall be prepared by mixing the epoxy resin and hardener. The proportion of the mixture shall be as recommended by the manufacturer. Suitable weigh scales/volumetric gauges shall be used for gauging quantity of resin and hardener. The proportion of resin and hardener used shall not reduce the properties below that given in Annexure I. POLYESTER RESIN The polyester resin system shall be prepared by mixing the polyester resin, catalyst and accelerator. The proportion of the mixture shall be as recommended Page 2 of 7

by the manufacturer. Suitable weigh scales/volumetric gauges shall be used for gauging exact quantity of resin, catalyst and accelerator. While preparing the mixture, accelerator shall never be mixed with catalyst. The accelerator shall be blended with resin first and the catalyst added immediately before use. Though the proportion of resin, catalyst and accelerator may be changed to reduce gel time, care shall be taken so as to not to reduce the properties below that given in Annexure II. The above resin mixture must be used within its gel time. 4.3 APPLICATION OF FIRST COAT OF RESIN MIXTURE The first coat of resin mixture shall be applied to the metal surface within ½ hour of completion of surface preparation. The application shall be done using a brush so as to completely cover the substrate. 4.4 WRAPPING OF FIBRE GLASS MAT The chopped strand fibre glass mat cut to appropriate dimensions shall be wrapped onto the surface as soon as the first coat is tacky. The wrapping shall be accompanied by first coating the initial coat with the resin mixture and then wrapping it with fibre glass mat so that it gets impregnated with the resin. The fibre glass mat shall be levelled with a roller to avoid wrinkles or folds. There shall be an overlay of ends of at least 50 mm of the fibre glass mat. Except on asymmetrically contoured surface the fibre glass mat shall be applied in a single piece upto the maximum manufactured width. In case of asymmetrically contoured surfaces like valves the maximum no. of pieces of fibre glass mat shall be that which is required to avoid wrinkles. In order to build the thickness a second layer of fibre glass mat shall be similarly wrapped. The wrapping shall be started when the earlier applied resin is still tacky. 4.5 APPLICATION FINAL COAT OF RESIN MIXTURE After wrapping the fibre glass mat a final coat of resin mixture shall be applied over the glass mat before the resin with which it is impregnated sets hard. The top coat must completely cover all the glass fibres. On completion the resin to glass ratio shall be 2:1 by weight. 4.6 CURING After the final coat the FRE/FRP lining shall be cured by drying in air for at least 24 hours prior to putting it to use.

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5.0 INSPECTION Samples of the materials used by the contractor shall be submitted for testing purpose. Contractor shall submit manufacturer's certificate for all the materials. Contractor shall procure the materials from BPCL approved manufacturer/s only. In case of other manufacturers prior approval of BPCL shall be sought. Inspection stages shall be : i. Material compliance (test certificates must be available). ii. Surface preparation (Inspection to certify). iii. After wrapping of fibre glass mat (random check). iv. Completion of final coat (Inspection to certify). After completion of final coat, lining shall be offered for inspection. The entire surface shall be free from cracks, traces of bubbles, lack of adhesion, hollow spaces etc. The hollow spaces shall be checked by tapping with a wooden mallet. v. Lining Thickness A sample of size 50 mm x 50 mm shall be cut & removed at every 3 m interval in staggered direction to determine the thickness and bond of the coating. The same shall be repatched in standard manner as stated above after inspection. vi. Spark Testing The contractor shall furnish and operate an electric powered holiday detector of 10,000 Volts output for certifying that lining is free from holidays. The same shall be witnessed by Inspection Department. Spark testing shall be done only after a minimum of 24 hours after the completion of final coat.

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ANNEXURE I SPECIFICATION FOR EPOXY RESIN The epoxy resin shall be prepared using epichlorohydrin and bisphenol A. The curing agent shall be an Aromatic amine. The properties of cured resin with reinforcing mat shall be the following : TESTING STANDARDS

Epoxy value

5.2 to 5.4 Eq/Kg

Tensile strength

9000 - 10000 psi.

ASTM D638

Flexural strength

16000 - 17000 psi.

ASTM D790

Heat distortion temp.

80 deg. C.

ASTM D648

Water absorption at 25 deg. C (after 72 hours)

0.2% (max)

BIS 6746

Excellent upto 70 deg. C.

BIS 6746

Chemical resistance in sea water Suitable curing temp.

30 to 40 deg. C.

Recommended manufacturer for supply of Epoxy Resin is : 1. M/s. Hindustan Ciba Giegy. The products generally meeting the above specification is : Resin Hardener

- Araldite GY 257 - HY 830

NOTE : Materials to be accompanied by manufacturer's test certificate.

ANNEXURE II SPECIFICATION FOR UNSATURATED POLYESTER RESIN The unsaturated polyester resin shall be an isopthalic acid based resin. It shall be prepared using suitable organic acid and a polyols. The monomer used shall be styrene. The curing agent will consist of cobalt (accelerator) and methyl ethyl

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ketone peroxide (catalyst). The properties of cured resin without reinforcing mat shall be the following : TENSILE STANDARD

Tensile strength

9000 - 10000 psi.

ASTM D638

Flexural strength

16000 - 17000 psi.

ASTM D790

100 deg. C. min.

ASTM D648

0.65% (max)

BIS 6746

Heat distortion temp. Water absorption at 25 deg. C. (after 28 days) Styrene content

30 to 40%.

Chemical resistance in sea water Suitable curing temp.

Exellent upto 70 deg. C.

BIS 6746

30 to 40 deg. C.

Recommended manufacturer for supply of Polyester Resin is : 1. M/s. Bakelite Hylam. The product generally meeting the above specification is : Resin Catalyst & Accelerator

- Hylak Resin HSR 8131. - Q-8013 and S-1021.

NOTE : Materials to be accompanied by manufacturer's test certificate.

ANNEXURE III SPECIFICATION FOR CHOPPED STRAND FIBRE GLASS MAT The fibre glass reinforcing mat shall be manufactured as per standard BIS-11551 or BS-3496. It shall have the following properties: TYPE - 'E' Glass Fibre Chopped Strand mat. Average strand diameter

: 8 to 10 microns

Strand length

: 25 to 51 mm.

Width

: 100 to 150 cm.

Moisture content by mass

: 0.5% (max).

Loss on ignition by mass

: +/- 2% (max).

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Average mass per unit area

: 450 gm/m sq

Cross breaking strength of laminate

: Dry 205 MPa, Wet 155 MPa

Conductivity of water extract

: 125micromhos/cm(max).

Coupling agent

: Silane.

NOTES :1. The mat shall be reasonably uniform in colour. It shall be free from discoloured patches, wet patches, oil and grease spots and other contaminations. 2. The mat shall comply with the above specifications for a period of not less than one year when stored. 3. Materials to be accompanied by manufacturer's test certificate. 4. MARKINGS Each roll or its container shall be clearly marked with the following information : a. The name or trade mark of the container. b. The nominal width of the roll (m). c. The nominal length of the roll (m). d. The nominal mass per unit area of the mat (gm/m2) e. Month and year of the manufacture. Recommended manufacturers for supply of chopped strand mat are: 1. M/s. FGP 2. M/s. UP TWIGA 3. M/s. Ceat TYRE.

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