Design And Selection Of Fluoroplastic Lined Pipe Fittings

For chemical and petrochemical processing, specify fluoropolymer lined pipe (flanged, DN15-DN600, 3.0MPa) to convey acids, caustics, and solvents. PTFE liner provides a chemical barrier between aggressive media and the steel outer shell. Select PTFE for -29°C to 180°C. Install in acid transfer, solvent lines, and hazardous chemical feed systems. Flanged connections enable direct installation. This design prevents corrosion, permeation, and leaks. Support pipe to prevent flange stress. Tighten bolts evenly to specified torque.

Chemical and Petrochemical Hazardous Service Requirements

Chemical plants handle hydrochloric acid, sulfuric acid, caustic soda, and organic solvents. These fluids attack unprotected metals. They degrade standard plastic piping. Leaks at flanged joints or through corroded walls cause safety and environmental hazards.

Key threats addressed:

•  Corrosion – acid attack on metal pipe walls.

•  Permeation – fluid migration through liner materials.

•  Temperature limits – PTFE handles -29°C to 180°C.

•  Safety – toxic or flammable fluid releases.

The ptfe lined pipe provides chemical resistance across a wide pH range. The fluoropolymer liner prevents direct metal contact with corrosive fluids.

Design and Specifications

Lined pipe consists of a steel outer shell with a seamless PTFE liner extruded or molded inside. Flanged connections enable direct installation. The liner thickness is typically 3-4mm for corrosion resistance.

Key specifications:

• Outer shell: Carbon steel (A106 Gr. B) or stainless steel (304/316)

• Lining: PTFE

• Connection: Flanged (ASME B16.5, EN 1092-1)

• Sizes: DN15 to DN600 (1/2" to 24")

• Pressure: 3.0MPa (Class 300)

• Temperature: -29°C to 180°C

The seamless liner construction eliminates weld lines that could become permeation paths. The 3.0MPa pressure rating handles high-pressure chemical transfer applications.

Applications in Chemical and Petrochemical Processing

Fluoropolymer lined pipe is installed in systems where corrosion resistance is required.

Typical applications:

• Acid transfer lines (hydrochloric, sulfuric, hydrofluoric)

• Caustic soda distribution systems

• Solvent and chemical feed lines

• Chlor-alkali process piping

• Pharmaceutical intermediate transfer

The ptfe lined construction handles aggressive media including organic solvents and oxidizing agents. Piping systems provide long service life in chemical and pharmaceutical plants.

PTFE Lining Properties

PTFE suits most chemical services up to 180°C and 3.0MPa. The liner remains chemically inert throughout service life. The flanged connection enables direct installation into standard piping systems.

Installation and Maintenance

Installation requires aligning flanges with appropriate gaskets. The pipe should be supported to prevent stress on flanged joints. Proper bolt torque ensures seal integrity.

Installation points:

1. Align flanges with proper gaskets.

2. Tighten bolts evenly to specified torque.

3. Support pipe to prevent flange stress.

4. Verify seal integrity after installation.

The ptfe lined pipe requires no internal coating maintenance. Regular flange bolt torque checks are recommended. When replacing components, ptfe lined pipe manufacturers provide standard dimensions for interchangeability.

Why Specify Fluoropolymer Lined Pipe

1. Provides corrosion resistance for aggressive chemical service.

2. Handles pressures up to 3.0MPa (Class 300).

3. Supports temperatures from -29°C to 180°C.

4. Reduces maintenance frequency in chemical plants.

5. Protects metal shell from corrosion and permeation.

Fluoropolymer lined pipe is a solution for chemical and petrochemical processing requiring corrosion-resistant piping. The ptfe lined pipe remains the standard choice for general chemical service up to 180°C and 3.0MPa. The pfa lined pipe offers enhanced high-temperature performance for applications exceeding 180°C. Specify lining material based on temperature and chemical exposure to ensure reliable performance. The flanged connection and 3.0MPa pressure rating suit high-pressure chemical transfer applications.

FVF Fluorine Lined Pipe Fittings

• The working temperature of FVF lined pipe fittings is high at the range of -29°C-180°C; except the molten alkali metals, element fluorine and aromatic hydrocarbon, lined products can be used in any chemical medium.
• Vacuum resistance. In the range of -29°C-150°C, it is applicable for vacuum condition. In chemical production, the vacuum condition occurs due to cooling, longitudinal emissions, or medium backflow. 
• It is high-pressure resistant . Within temperature working condition, it can sustain the working pressure of 3.0MPa.
• It is penetration Resistant.It has excellent antiosmosis by adapting the high-quality PTFE and making it of high density and enough thickness after advanced lining processing.
• PTFE advanced lining molding process achieved the status of syn chronous hot expansion or cold shrinkage for steel components and fluorine plastic. 

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