PTFE  Gasket/ PTFE Filled  Gasket

Ⅰ、Features

   PTFE envelope gasket is a kind of static seals.It is composed of elastic materials such as compressed asbestos sheet,rubber,ceramics,etc. And PTFE envelope cover.

   PTFE has superior properties against chemical(not affected by all chemicals except molten alkali metal and fluorine at elevated temperature) and temperature(from - 180℃ ~ +250℃）The coefficient of static and dynamic friction of PTFE are every low.PTFE is the best of the “non-stick”material. It has excellent anti weathering and aging characteristics.

Ⅱ、Types and Specifications:

PTFE Envelope Gasket

Note: （Thickness）Gasket slot width

PTFE Flange Gasket

Different standards of different specifications gasket, according to customer drawings for processing

Ⅲ、Applications

PTFE envelope gasket is used to seal pipe flange anti joint of industrial machinery apparatus which is lined with rubber,plastic ceramics graphite etc.

PTFE Envelope Gasket Technical Introduction

PTFE envelope gaskets are high-performance sealing elements composed of a polytetrafluoroethylene (PTFE) envelope layer composite with various reinforcing core materials. This product perfectly integrates the exceptional chemical inertness of PTFE with the mechanical strength of reinforcing materials, establishing a benchmark solution in modern industrial sealing.

Core Value Proposition

1. Chemical Protection Expert

   Withstands highly corrosive media like 98% concentrated sulfuric acid and 37% hydrochloric acid, maintaining a stable seal under alternating acid-base conditions.

2. Extreme Condition Guardian

   · Cryogenic Type: No embrittlement in -196°C liquid nitrogen environments.

   · High-Temperature Type: Short-term temperature resistance up to 300°C (graphite reinforced version).

3. Intelligent Sealing Innovation

   Latest models integrate pressure-sensing fibers for real-time seal status monitoring (optional).

Technology Evolution Milestones

· Fifth-generation products utilize gradient density compression technology, increasing edge sealing pressure by 50%.

· Nano-Al₂O₃ modified versions achieve a 60-year design life in nuclear power applications.

· Laser micro-perforation treatment technology increases sealing contact area by 70%.

Typical Application Scenarios

· Chemical Industry: Chlor-alkali production equipment, pickling line flange seals.

· Energy Sector: LNG terminal cryogenic pipelines, nuclear power plant main pumps.

· Electronics Manufacturing: Ultra-pure media transfer in semiconductor wet process equipment.

· Biopharmaceutical: Sterile bioreactors meeting FDA requirements.

Current Technology Frontiers:

· Graphene-modified gaskets under testing achieve thermal conductivity of 25 W/(m·K).

· 4D printed shape-memory gaskets can self-adapt to flange deformation.

· Biodegradable PTFE composite materials are in the pilot testing stage.

This product series covers full sizes from DN15 to DN3000, has passed 18 international certifications including ASME and PED, and has been successfully applied in major engineering projects across more than 50 countries worldwide.

Basic Characteristic Parameters

Parameter Item	Technical Indicator	Test Standard
Material Composition	PTFE + Metal/Non-metal Core	ASTM D1710
Operating Temperature	-196°C ~ +260°C (short-term 300°C)	ASTM D696
Rated Pressure	0.6 ~ 15 MPa (depending on structure type)	ASME B16.20
Compression Rate	15 ~ 25%	ASTM F36
Recovery Rate	≥ 15%	ASTM F36
Density	2.1 ~ 2.3 g/cm³	ASTM D792

Structure Type Comparison

Type	Core Material	Pressure Range	Characteristics	Applicable Standard
Standard Type	Rubber	≤ 2.5 MPa	Economical, General Purpose	DIN 2690
Reinforced Type	304 Stainless Steel	≤ 10 MPa	Compression & Creep Resistant	ASME B16.21
High-elasticity Type	Graphite	≤ 6 MPa	Good High-Temperature Stability	EN 1514-1
Conductive Type	Carbon Fiber	≤ 4 MPa	Surface Resistance 10⁴ Ω	ISO 8031
Ultra-high Purity Type	PFA Composite	≤ 3 MPa	Metal Ion Leachables < 0.1 ppb	SEMI F57

Typical Structure Types

Type	Structural Features	Applicable Pressure	Typical Application
Rubber Core Envelope	PTFE envelope over NBR/SBR rubber	≤ 2.5 MPa	Low-pressure acid/alkali pipelines
Metal Serrated Core	Stainless steel corrugated plate + double-sided PTFE envelope	≤ 15 MPa	High-pressure flanges in petrochemicals
Graphite Reinforced	PTFE + Expanded Graphite composite layer	≤ 10 MPa	High-temperature steam systems
Teflon® Composite	PFA inner layer + PTFE outer layer	≤ 6 MPa	Ultra-high purity electronic chemical transfer

Dimension Parameter Table

Nominal Diameter DN	Flange OD (mm)	Gasket ID (mm)	Gasket Thickness (mm)
15	95	18	1.5 / 3.0
50	165	55	2.0 / 3.0
100	220	105	2.5 / 4.5
300	400	305	3.0 / 5.0
600	705	610	4.0 / 6.0

Industry Certification Comparison

Certification Standard	Certification Content	Applicable Industry
FDA 21 CFR 177.1550	Food Contact Safety Certification	Food / Pharmaceutical
TA Luft	German Air Purity Standard	Chemical / Environmental
NORSOK M-710	Norwegian Petroleum Standard	Oil & Gas Extraction
ASME B16.20	US Standard for Pipe Flange Gaskets	General Industry
ISO 10993-5	Biocompatibility for Medical Devices	Medical Equipment

Selection Guide by Operating Condition

Operating Requirement	Recommended	Type Technical Basis
Strong Acid + High Pressure (10 MPa)	Titanium Core Reinforced Type	Corrosion Resistance + High Strength
Cryogenic (-150°C)	Nano-SiO₂ Modified Type	Anti-Cold Flow
Frequent Disassembly	Graphite Filled Composite Type	Excellent Recovery Performance
Sterile Environment	Electropolished PFA Composite	Type Ra ≤ 0.5 μm
Explosive Atmosphere	Carbon Fiber Conductive Type	Surface Resistance ≤ 10⁶ Ω

Innovative Technology Highlights

1. Surface Micro-structuring: Laser-engraved micron-level patterns increase sealing contact area by 70%.

2. Gradient Density Design: Multi-layer composite compression technology creates >20% higher density at the edges than the center.

3. Intelligent Early Warning: Embedded conductive fiber network for real-time seal failure monitoring (optional).

Industry Applications

· Chemical Industry: Reactors, pump/valve seals, resistant to special media like HF acid.

· Pharmaceutical Equipment: Sterile pipeline connections meeting FDA requirements.

· Energy Sector: LNG pipeline flanges, nuclear power plant cooling systems.

· Food Processing: Dairy fermentation tanks, juice filling line seals.

Selection Key Points

1. Media Compatibility: Verify PTFE resistance to specific chemicals.

2. Operating Parameters: Select core material type based on temperature/pressure (e.g., rubber core prohibited >150°C).

3. Flange Standard: Match flange face type (RF/FF/RJ, etc.) and dimensional accuracy.