Technical Details

Lined Pipe & Fittings Material Details

PTFE Lined Pipe & Fittings

LinedPipe.Com offers 1/2 inch through 12 inch PTFE lined pipe and fittings in both carbon steel and stainless steel in standard and special configurations. PTFE liners are produced using a proprietary technology and the highest quality resins. This process creates free sintered liners with superior properties for strength and resistance to permeation.
Pipe liners are ram paste extruded or isostatically molded and have consistent, dimensional accuracy for excellent performance in service. The liners are installed in A587, A106 and A53 steel pipe with rotating A395 ductile iron or A105 forged steel flanges.
The LinedPipe.Com product offering will be expanding as new shapes and sizes are developed.  We invite you to bring us your toughest plastic lined pipe problems.
Do you have a specific pipe or fitting need that you don’t see addressed here? Get in touch with us! 

Plastic Liner Thicknesses

LinedPipe.Com Liner Data

Carbon Steel Fittings Material Details

All fittings conform dimensionally to ANSI B 16.5

Carbon steel metallurgy:

  • One-piece 90° and 45° elbows
    • Body is ASTM A587 pipe or ASTM A53/A106 Gr B steel
    • Flanges are ASTM A105 forged steel
  • Welded 90° and 45° elbows
    • Body is ASTM A234 Gr WPB steel
    • Stub ends are ASTM A587, ASTM A53/A106 Gr B or SAE 1010-1030 steel
    • Flanges are ASTM A105 forged steel
  • Tees, Instrument tees, Crosses, Laterals
    • ASTM A105 machined forged steel, SAE 1010-1030 steel or ASTM A53/A106 Gr B steel
    • Stub ends are ASTM A587, ASTM A53/A106 Gr B steel
    • Flanges are ASTM A105 forged steel
  • Concentric reducer
    • Body is SAE 1010-1030, ASTM A516 Gr 70, ASTM A105, or ASTM A234 steel
    • Stub ends are ASTM A587, ASTM A53/A106 Gr B or SAE 1010-1030 steel
    • Flanges are ASTM A105 forged steel
  • Eccentric reducer
    • Body is SAE 1010-1030, ASTM A516 Gr 70, ASTM A105, or ASTM A234 steel
    • Stub ends are ASTM A587, ASTM A53/A106 Gr B or SAE 1010-1030 steel
    • Flanges are ASTM A105 forged steel
  • Reducing flange
    • Material is ASTM A105, ASTM A516 Gr 70 or SAE 1010-1030 steel 
Stainless Steel Fittings Material

All fittings conform dimensionally to ANSI B 16.5

Stainless steel metallurgy:

  • One-piece 90° and 45° elbows
    • Body is ASTM A312 pipe
    • Flanges are ASTM A182 forged stainless steel
  • Welded 90° and 45° elbows
    • Body is ASTM A403
    • Stub ends are ASTM A312
    • Flanges are ASTM A182 forged stainless steel
  • Tees, Instrument tees, Crosses, Laterals
    • ASTM A479 machined stainless steel
    • Stub ends are ASTM A312
    • Flanges are ASTM A182 forged stainless steel
  • Concentric reducer
    • Body is ASTM A479 or ASTM A403 stainless steel
    • Stub ends are ASTM A312
    • Flanges are ASTM A182 forged stainless steel
  • Eccentric reducer
    • Body is ASTM A403 stainless steel
    • Stub ends are ASTM A312
    • Flanges are ASTM A182 forged stainless steel
  • Reducing flange
    • Material is ASTM A479
Quality Standards

All products comply with ASTM F1545 Standard Specification for Plastic Lined Ferrous Metal Pipe, Fittings and Flanges.

All welds are in compliance with ASME B31.3 and welders are certified to Section IX of the ASME Boiler and Pressure Vessel Code.

Carbon steel components are sandblasted and primed with rust preventative gray primer and are suitable for top coating in the field. Special coatings are available on request.

All lined parts are  subjected to a minimum 10,000 volt spark test to detect liner defects. Any audible or visible spark is cause for rejection of the liner.

All flared surfaces are protected by wooden end covers to insure their integrity during shipping and handling. Covers must remain in place prior to installation.

The manufacturer’s name, ASTM F1545 designation and liner type are provided on the identification band located on the part.  All parts are metal stamped with liner type and tracing number on the flange where possible.

 

Plastic Liner Characteristics

Flange Details

Recommended Bolt & Stud Lengths

Recommended Fastener Torque

Recommended Bolt Torque (ft-lbs)

 

Recommended Torque Procedures

The same general techniques used to install flanged carbon steel piping systems can be applied to plastic lined piping systems.

When assembling flange connections, always use a full compliment of clean, new high strength A197-B7 bolting. If using stainless steel bolting, the bolts should be A193 Gr. B8M, class 2A and nuts should be A1193 Gr. B8M Class 2B. If other bolting materials are used, the end user must ensure that the new bolting material strength properties exceed the calculated bolt stress values to be generated in making the piping connection.

  • Always use flat washers on both sides of the connection.
  • Tighten the flange bolts with a calibrated torque wrench to the specified bolt torques. NOTE: If using anti-seize compounds, the torque values will be different.
  • Tighten the flange bolts with a torque wrench using a crisscross pattern that alternately tightens the bolts located 180° apart.
  • Using this pattern, tighten the bolts in 20% increments of the final bolt torque until 80% of the final bolt torque has been achieved.
  • For tightening to the final torque values, tighten the bolts sequentially clockwise once around the flange. This will help insure that the bolts are evenly stressed.
  • Care should be taken to prevent over-torqueing, which will cause damage to the sealing surfaces.

NOTE: when bolting together dissimilar materials, always tighten to the lowest recommended torque of the components in the joint. Using higher torques may cause excessive deformation of the ‘softer’ material in the joint. Install a 1/2” thick spacer between plastic lined pipe or fittings and other plastic lined components, particularly valves, if the diameters of the raised faces are different. Belleville washers are not recommended for use with PTFE lined products.

Re-torqueing

A re-torque should be applied a minimum of 24 hours after the initial torque or after the first thermal cycle. This allows for seating of the plastic and for relaxation of the bolts. Torqueing should only be done on the system in the ambient, cooled state, never while the process is at elevated temperature or excessive force could be applied to the plastic faces. Never disassemble a flange joint in a hot system. Wait until the system has cooled to ambient temperature.

Hydrotesting

Normally, after initial torque and re-torque, a hydrotest should be performed following ANSI requirements. If a flange leaks, first check the torque values and then tighten in 10% increments over the specified bolt torques until sealed. However, if 150% of the specified torque value is reached and the flange joint still leaks, stop and disassemble the flange joint. Something else is likely wrong such as a scratched plastic face. Only after the hydrotest has been successfully completed and any leaks corrected, can the pipeline be signed off and commissioned.

Annual Re-torqueing

Re-torqueing should be done at least annually thereafter, especially if the process line experiences elevated temperatures or thermal cycling. Torqueing should only be done on the system in the ambient, cooled state and never while the process is at an elevated temperature, excessive force will likely be applied to the plastic faces.

NOTE: the maximum recommended torque values are suggested for lined systems operating at or near the maximum recommended pressures and temperatures. Systems operating under less severe conditions can in general experience leak-free performance using lower torque values. Additionally, any time gaskets or spring type washers are used, we suggest using the minimum recommended torque value and that the torque be increased only to obtain satisfactory sealing. For systems that will require frequent disassembly, we suggest using the minimum recommended torque value initially to avoid distortion of the plastic face.