Spiral Wound Gasket for HF-Alky Services
Euroseal® Double Seal Soft is a high-performance spiral wound gasket developed by General Packing Italy for HF-Alky services. It is designed to ensure maximum reliability in the most demanding applications. Its advanced structure features a dual sealing system: a smooth metallic inner ring coated with expanded PTFE acts as the primary barrier, while the spiral wound element functions as the secondary seal.
Thanks to the expanded PTFE coating, the inner ring not only provides reliable sealing but also protects the spiral and the flanges from corrosion, abrasion, and scaling. This makes it an ideal solution for plants operating under aggressive conditions, such as alkylation units, where flange integrity is often compromised by erosive phenomena and solid deposits.
Operating Conditions
- Operating Temperature*: from -200°C to +260°C
- Pressure*: up to 100 bar
*Maximum theoretical values
Certifications Spiral Wound Gasket for HF-Alky Services
- VDI 2440 – Fugitive Emissions
- API 6FB – Fire Test
Patent
Patent filed with the Italian Ministry of Economic Development
Your Gasket, Configured to Your Plant Specifications
Each plant has its own line specifications, including the use of specific materials. The Euroseal® Double Seal Soft gasket can be configured with the following options:
- Inner ring: AISI 304/316L/321/347, MONEL® 400, and various thicknesses
- Spiral: stainless steel or special alloys, with graphite or PTFE filler
- Outer ring: carbon steel, stainless steel, or MONEL®
- Expanded PTFE coating in various thicknesses
Related Products
Euroseal® Double Seal G
Euroseal® Double Seal T
Applications
• Thermoelectric power stations.
• Petrolchemical plants.
• Steel industries.
• Pulp and Paper industries.
Technical FAQ
What is a Double Seal Soft spiral wound gasket for HF and ALKY?
The Euroseal® Double Seal Soft is a semi-metallic gasket designed to provide dual sealing through the combination of a metallic spiral and an inner camprofile ring coated with expanded PTFE. This configuration ensures high reliability in critical chemical processes such as hydrofluoric acid (HF) services and alkylation units.
In which plants is this gasket used?
The Double Seal Soft gasket is specifically recommended for:
- Alkylation units
- Refineries
- Petrochemical sector
- Systems handling HF or other aggressive chemicals
What materials are used to ensure compatibility with hydrofluoric acid?
For HF services, corrosion-resistant metals are selected, such as Alloy 400 (Monel®) for the inner ring and spiral. The expanded PTFE coating isolates the graphite and protects against crevice corrosion, ensuring chemical compatibility and long-term durability.
What is the difference between a standard spiral wound gasket and a Double Seal?
The Double Seal provides a second internal sealing line thanks to the camprofile machining of the inner ring and the insulating coating. This design:
- Enhances sealing under extreme conditions
- Protects the spiral from corrosive attacks
- Extends gasket service life
Which certifications are available for this gasket?
Double Seal Soft gaskets are tested according to:
- VDI 2440 – 2200
- API 6FB Fire Test
- Fugitive emissions certifications
Are there variants of the Double Seal for other fluids or operating conditions?
Yes. In addition to the Double Seal Soft, the following variants are available:
