Execution of insulation underground pipelines, should be implemented in three phases:

ayegh_sard

The Surface Area of a Pipe Must be Clean.

Pipe surface should be clean and free of mud, dirt, oil, bitumen, lubricants and any other material.

To clear the convex levels on the tube, wire brush or hammer or any other suitable means can be used.

.‌

Standard SSPC SP-1

Before blasting operations, the pipe surface must be cleaned of chemicals or oil according to SSPC SP-1 standard. For this purpose use producer approved insulation strips. At the heating time to wipe the pipe surface do not use temperature of more 150 degrees Celsius.

Standard ISO 8501-SA21/2

When sandblasting or shot blasting cleaning the pipes should be in accordance with EN ISO 8501-SA21 / 2 is.

General commands:

Execution of insulation underground pipelines, should be implemented in three phases:

  1. Implementation of Primer
  2. Anti-corrosion insulation strip (bottom strip)
  3. Mechanical protective strip (upper strip)

Preferably use skilled workers to install the insulation.

Equipment and systems used in the preparation of the pipe surface must comply with standard EN-ASTM-DIN-IGS-IPS-AWWA C214.

Instructions for Cleaning the Surface Area of a Pipe

.

Priming and Striping Should be Done in a Day.

Be sure process of priming and striping be done in a day. Do not leave the striping into the day after tomorrow of priming.‌ In no way, the blasted or primed tube should not leave without strip.

Implementation of cold tapes (lower and upper)

  1. Lower and upper strips run in the same way on the surface of the primer tube. This strip can be execute by use of suitable spiral strip devices and approved by manufacturer of insulation tapes.
  2. After wrapping tape on the tube by roller create the necessary pressure to contact adhesive strip and the tube.
  3. If necessary, use mechanical devices suitable for twisting and tightening strip away the pipe.
  4. At the end, a smooth without wrinkles and air bubbles stripped tube must be established.
  5. The tension at the runtime should be such an amount that increases one to two percent the strip length.
  6. Implementation of strip must be angled and springy to overlap the strip during the process. This overlap can be between 1inch to 50% of the strip’s width.
  7. When the strip is finished and a new strip is used, the new strip must overlap up to 15 cm of the prior strip.‌
  8. Do not insult about 20 cm from the beginning and the end length of tube with Lower and upper insulting strips. This gap that is called «cut back» must be free due to welding of the pipes.
  9. The proper temperature environment for stripped joint operation should be about 60 to 20° C. In very cold conditions, strips should indirectly be heated prior to execution. Choosing the right atmosphere is very important for insulation.‌

Necessary instructions:

  1. Insulated Pipes can be tested by HOLIDAY DETECTOR tests.
  2. Insulated Pipes must be buried as soon as possible.
  3. If there was no possibility of burying pipes, and the pipes maintain some time in open air, color change of the Outer wrap layer may occur. However, this color change does not affect product quality.
  4. Insulated Pipes sections should be protected by soft layer (padding) in order to avoid any damages.
  5. Transportation of such tubes should be done very carefully.

Primer Stages  must Accompanied by Standards EN-ASTM-DIN-IGS-IPS-AWWA C214 as the following conditions:

  1. Execute primer in layers with a thickness of 30 to 50 microns on the pipe surface that will vary depending on performance and weather conditions.
  2. Execute to some extent the primer that can operate the surface with stripped joint immediately. The right time in order to do so is when the primer be stiffed to such extend that by touching it fingerprints remain on the primer layer.
  3. Protect the primer layer against moisture, dirt and so on.
  4. Before running primer, stir thoroughly primer solution.
  5. Always do the implementation of the primer on dry surface,‌ If due to severe cold weather the primer stiffed, using heat to return Primer its original condition by no means is allowed.