Long Length Reinforced Thermoplastic Pipes (LLRTP)

What are LLRTP pipes?

• It is a flexible pipe made of thermoplastic layer reinforced by fiber glass layer.
• LLRTP stands for long length reinforced thermoplastic pipe.
• LLRTP can have a continuous length of 650 meters coiled in one spool.
• Max size available in market is 8”.

What are the advantages and limitations of LLRTP pipes?

The advantages are as follow:

1. Corrosion resistance
2. Better hydraulic properties than CS
3. Low life cycle cost
4. Ease of handling and installation
5. Maintenance Free
6. Construction time is significantly less than other linepipes (10 times less than CS+PE)

The limitations are as follow:

1. Maximum operating temperature – 85 degrees Celsius
2. Maximum available pipe size is 8”
3. Maximum GOR – 300

How are LLRTP pipes Loaded, transported, and stored?

The loading and unloading procedure shall be as follow:

• Spools contain a lifting attachment for loading and unloading.
• Spools are lifted using a crane with spreader bar and chains.

The transportation procedure is as follow:

• LLRTP pipe is coiled on the shipping reel made of steel.
• A trailer us used for transporting the LLRTP spools – max 2 spools per trailer.
• Spools normally are transported to site with deployment frame for immediate deployment.
• Spool must be secured using chains.

The storage shall be as follow:

• Spools shall be stored in a flat ground.
• Spools shall be placed on wooden skids to prevent damage to the lower flange.
• End pipes should be sealed to prevent water and wildlife from entering.

How are LLRTP pipes installed?

• Deployment Procedure:
  • Spools can be deployed by 2 ways:
    • A Chain Drive A-Frame – Vertical
    • Carousel – Horizontal
  • Carousel has two hydraulic rubber tires used to rotate the spool and to control the deployment rate.
  • Two level-wind arms that contain the line pipe on the reel to support pipe wraps during deployment.
  • Pulling head is attached to the end of the pipe using screws for pulling purposes.
  • Calibrated shear loop supplied by the vendor shall be used to avoid excessive tension on the line pipe.
    • No Crossing:
      • FCP pipe will be deployed by rotating the spool and the trailer will move. While the other of pipe is stationery and being hold by a JCP.
    • Crossing:
      • In this case the JCP will move, and the trailer will be stationery so that LLRTP pipe can be pulled through casing pipes at crossings.
• Jointing Procedure:
  • Pipe End Preparations:
    • Cutting edge to 90 degrees
    • External HDPE Jacket removal
    • Pipe riming
    • Edge buffing
  • O-Ring Installation
  • Inserting slip, nut and mandrel
  • Tightening by wrench
  • Jacket installation and Wrapping
• Windrow Procedure:
  • A windrow shall be maintained all over the flowline except the location of joints.
  • After successful hydrotest, the exposed joints shall be backfilled.

What is the procedure for LLRTP Hydrotest?

Procedure:

1. Cleaning (low density soft pig)
2. Flushing & water filling
3. Thermal stabilization for 2 hours
4. Pressurizing (1 bar/min)
5. Pressure holding for 4 hours.
6. Depressurizing

Requirements:

1. Test pressure = 1.25 x DP
2. Duration = 4 hours