Non Crystalline Viscous Elastic Solid Polyolefin Coating

Non Crystalline Viscous Elastic Solid Polyolefin Coating Tape

Viscous Elastic tape consist of a cold applied, non-toxic corrosion preventing wrap coating material that has

non-cross linkable low viscosity polyolefin)

The Inner Wrap and complete coating meet ISO 21809-3 standards

Visco-Elastic Coating Materials covered Visco-Elastic Tape,Visco-Elastic Mastic,PVC Outerwrap Tape,Polypropylene Anticorrosion Tape,High Temperature Visco Tape

Application Condition:

Operating temperature -30Deg C to +95Deg C

APPLICATION METHOD

Surface Preparation – prior to application of Inner Wrap / Molding compound

1.1 Mechanically remove all weld spatters, laminations, slivers, sharp edges, high points, and other visual surface irregularities from the steel surface, which might penetrate into the corrosion prevention coating layer.

1.2 Degrease the surfaces to be coated, if necessary, to remove any grease or oil contamination, using Iso propanol. No thinners shall be used.

1.3 The surface of the pipe and any adjacent line coating shall be dry and clean. Remove loose

corrosion residue, loose mill scale, dust or other loosely adherent contaminants.

1.4 Clean the surface of the bare steel to a cleanliness of St-2 / St-3 standard (by means of hand / machine wire cleaning) or to a Sa-1 standard by means of abrasive blasting ("brush-off" blasting), in accordance with ISO 8501-01. For the application of the visco elastic materials an anchor profile is not required, therefore it is not necessary to measure the anchor profile.

1.5 Finally, carry out a "Dust" test on the cleaned surfaces. Pieces of adhesive tape shall be applied on different places on the cleaned surface. When removing the tape pieces, the contamination on the tape indicates the degree of loose dust remaining on the surface and if additional dust cleaning is required.

1.6 Epoxy lined substrates shall be de-glossed and may be cleaned with a light abrasive sweep blasting or by abrading with sand paper, and degreasing by Isopropanol.

1.7 Prior to and during application, surface to be coated shall be maintained at a temperature at least +3 oC above the dew-point temperature and between -45 oC and +95 oC

2 Corrosion Prevention Inner Wrap applications

2.1 Before and during application, inner wrap shall be maintained within the temperature range +5 oC to + 70oC

2.2 Inner wrap shall be applied with the sticky side in contact with the substrate, wrapped without tension, avoiding air entrapment and without tape creases and wrinkling.

2.3 Inner wrap shall be wrapped with an overlap of 10mm. It shall overlap at least 50mm onto adjacent existing pipe coating. Overlaps between the end of a tape roll and the tape of a new roll shall be at least 100mm.

2.4 At terminations (start and end points) one, full straight wrapping shall be applied onto substrate, followed with wraps from “straight to spiral” and then continuing with spiral wrapping, with 10mm minimum overlap. End with one straight, circumferential wrapping.

2.5 Inner wrap application onto flanges and valves shall be applied as recommended by

Manufacturer.

2.6 The nominal thickness of the wrapping Band shall not be lower than 1.8 mm

8.2.7 Quality control Holiday Detection High voltage test shall be carried out on the Inner Wrap directly after application! At this stage in the coating process, holidays / gaps can easily be localized. Any holiday shall be repaired with the addition of new material and retested.

2.8 The High voltage Holiday test shall be done at 15kV. A clean, copper-brush probe is recommended for the holiday testing. In case a ring-probe is used, the test voltage shall be 20kV in order to compensate the less efficiency of a ring probe.

3 Mechanical Prevention Outer wrap application:

3.1 Prior to start of application, check the cleanliness and temperature of the surface to be coated is

according to the same guidelines as prior to the Inner wrap application.

3.2 Application of Outer wrap shall be done with tension. The first wraps of the Outer Wrap shall be done without advancing the roll. Always start the wrapping three to five millimeters inside the end of the corrosion prevention Inner Wrap tape. Start with two circumferential wraps around the pipe.

3.3 Apply the subsequent outer wrap under tension, spiral-wrapping by advancing the roll, with an overlap of minimum 50%. In this way a double layer of Outer wrap will be created. Subsequent rolls should overlap the previous tape-end by minimum 25 cm.

3.4 During the entire wrapping process, the applicator should apply the Outer wrap as smoothly as possible, avoiding air enclosures. It is important that optimal adhesion is achieved between the overlapping Outer wrap layers as well as the adhesion to the corrosion prevention Inner Wrap layer. This will ensure optimal performance of the mechanical prevention layer.

3.5 The wrapping should end 3-5 mm inside the Inner wrap, with two, NON-TENSIONED,

circumferential wraps around the pipe. A final visual quality control check should be carried out by a trained and certified inspector approving and reporting the quality of application. No further tests are needed and the coated section can be accepted.