Thermoplastic Isolator (TPI) – Technical Information

February 28, 2019

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What is Thermoplastic Isolator (TPI)?

Thermoplastic isolators provide optimum support and eliminate pipe contact with the supporting steel.

  • Moisture/water can be trapped between the pipe and support, which can initiate corrosion of the pipe
  • In addition, when TPI is placed between the pipe and the supporting structural steel, it can prevent cathodic reaction

Iron + Water + Oxygen = Rust  ➞  Corrosion

Piping Technology & Products can fabricate TPI designed for use with u-bolts. Our u-bolts, have a hot-dipped galvanized finish and are coated with Polyshrink. The Polyshrink acts as a barrier between the u-bolt and the pipe to prevent corrosion, and it also adds protection.

TPI Pipe
TPI Pipe (angle view)

TPI Pipe
TPI Pipe (front view)

Benefits of Thermoplastic Isolator (TPI):

  • TPI has a very high compressive strength
  • It is subject to very little “creep” over the period of time
  • TPI is easy to fabricate
  • Cutting and drilling holes can be easily done
  • Easy to Install
  • Very economical when compared to the leading competitor
  • It can be used with different types of pipe supports
U-Bolt with Thermal Plastic Isolator (TPI) & Polyshrink
U-Bolt with TPI

Installation of TPI:
TPI can be placed or attached to structural steel by three different methods.

  • Self-tapping screw or bolting
  • Double-sided adhesive tape
  • With u-bolt
Adjustable Pipe Supports with U-Bolt and TPI
Adjustable Pipe Supports with U-Bolt and TPI

Common Industry Application:

  • Petrochemical plants
  • Refineries
  • LNG plants
  • Offshore platforms
  • Wastewater plants
  • Parking garage
  • Marine pipelines


Types of TPI:
There is a total of 3 different types of TPI available based on thermal properties.

  • TPI White – Maximum Service Temperature 181°F
  • TPI Amber – Maximum Service Temperature 340°F
  • TPI Tan – Maximum Service Temperature 480°F

TPI Types

TPI (Thermoplastic Isolator): Properties & Various Grades
TPI WhiteTPI AmberTPI Tan
Property ValueASTM TestImperialImperialImperial
DensityD792 0.0516 lb/in30.0458 lb/in30.047 lb/in3
Tensile StrengthD63811,000 psi17,000 psi16,000 psi
Tensile Modulus of ElasticityD638450 ksi500 ksi630 ksi
Elongation (At Break)D63830%60%40%
Flexural Modulus of ElasticityD790450 ksi500 ksi600 ksi
Flexural StrengthD79013 ksi20 ksi25 ksi
Compressive StressD69516 ksi22 ksi20 ksi
Coefficient of FrictionQTM 550070.250.420.32
IZOD Impact (Notched)D2561 ft-lb/in0.5 ft-lb/in 0.6 ft-lb/in
Rockwell Hardness D785M 88M 115M 105
Maximum Service Temperature(Long Term)181ºF340ºF480ºF
Melting PointD3418347ºF410ºF644ºF
Coefficient of Linear ExpansionE83147 µin/in/ºF31 µin/in/ºF-
Flammability RatingUL94HBV-0V--0
Electric StrengthD149450 V/mil830 V/mil480 V/mil

Key Factors in choosing PT&P’s Thermoplastic Isolator over Competitors:

  • All suppliers of plastic components for these types of supports, purchase raw materials from some of the same sources
  • PT&P’s TPI is equivalent to competitors, but the price of TPI is much lower
  • In addition, TPI can be tested in any independent lab
Comparison between PT&P’s TPI White VS Leading Competitor
Property ValueASTM TestTPI - WhiteCompetitor
DensityD792 0.0516 lb/in30.0509 lb/in3
Tensile StrengthD638 11,000 psi 9,400 psi
Tensile Modulus of ElasticityD638 450 ksi 380 ksi
Elongation (At Break)D638 0.330-60%
Flexural Modulus of ElasticityD790 450 ksi 400 ksi
Flexural StrengthD790 13 ksi 13 ksi
Compressive StressD695 16 ksi 15 ksi
Coefficient of FrictionQTM 55007 0.250.25
IZOD Impact (Notched)D256 1 ft-lb/in 1 ft-lb/in
Rockwell Hardness D785 M 88 M 88
Maximum Service Temperature(Long Term) 181ºF 181ºF
Melting PointD3418 347ºF 329ºF
Coefficient of Linear ExpansionE831 47 µin/in/ºF 54 µin/in/ºF
Heat Deflection Temperature, 264 psiD648 250ºF 220ºF
Flammability RatingUL94 HB HB
Electric StrengthD149 450 V/mil 420 V/mil
Result from above comparison, both products are equivalent
Comparison between PT&P’s TPI Amber VS Leading Competitor
Property ValueASTM TestTPI – AmberCompetitor
DensityD792 0.0485 lb/in3 0.0462 lb/in3
Tensile StrengthD638 17,000 psi 16,500 psi
Tensile Modulus of ElasticityD638 500 ksi 500 ksi
Elongation (At Break)D638 0.630-60%
Flexural Modulus of ElasticityD790 500 ksi 500 ksi
Flexural StrengthD790 20 ksi 20 ksi
Compressive StressD695 22 ksi 22 ksi
Coefficient of FrictionQTM 55007 0.420.42
IZOD Impact (Notched)D256 0.5 ft-lb/in 0.5 ft-lb/in
Rockwell HardnessD785 M 115 M 112
Maximum Service Temperature(Long Term) 340ºF 340ºF
Melting PointD3418 410ºF 410ºF
Coefficient of Linear ExpansionE831 31 µin/in/ºF 31 µin/in/ºF
Heat Deflection Temperature, 264 psiD648 400ºF 400ºF
Flammability RatingUL94 V-0 V-0
Electric StrengthD149 830 V/mil 830 V/mil
Result from above comparison, both products are equivalent.
Comparison between PT&P’s TPI Tan VS Leading Competitor
Property ValueASTM TestTPI - TanCompetitor
DensityD7920.047 lb/in30.047 lb/in3
Tensile StrengthD63816 ksi16 ksi
Tensile Modulus of ElasticityD638630 ksi500 ksi
Elongation (At Break)D6380.40.2
Flexural Modulus of ElasticityD790600 ksi1000 ksi
Flexural StrengthD79025 ksi25 ksi
Compressive Stress D69520 ksi 20 ksi
Coefficient of FrictionQTM 550070.320.4
IZOD Impact (Notched)D2560.6 ft-lb/in1.0 ft-lb/in
Rockwell Hardness D785M 105M103
Maximum Service temperature(Long Term)480ºF480ºF
Melting PointD3418644ºF644ºF
Coefficient of Linear ExpansionE831--
Heat Deflection Temperature, 264 psiD648320ºF320ºF
Flammability RatingUL94V--0V--0
Electric Strength D149480 V/mil-480 V/mil-
Result from above comparison, both products are equivalent.


What is a welding lug?

November 2, 2010

A welding lug is a pipe support component consisting of a single plate of varying thickness, depending upon the load, which is welded to either a supporting structure or a supported pipe and used to join other support components together using pins.

Welding Lug Shown on a Constant Spring Support
Welding Lug Shown on a Constant Spring Support

What does long tangent mean for u-bolts?

Long tangent refers to the length of the straight leg portion of the u-bolt which specifies the height of the u-bolt.

Long Tangent U-Bolt for Refinery
Long Tangent U-Bolts

What are hanger rods?

Hanger rods are externally threaded components which are used to join internally threaded components of a pipe support assembly.

Rod and Clevis Assembly
Rod and Clevis Assembly

What is the importance of a pipe guide?

A pipe guide is used to permit pipe movement in a predetermined direction while restraining movement in other directions.

Cylinder Pipe Guides
Cylinder Pipe Guides