Kaxite Sealing is a China-based SS 304 with PTFE filler spiral wound gasket manufacturer and supplier. This CGI-style gasket is built with SS 304 / UNS S30400 V-shape stainless steel winding and PTFE soft filler, complete with an inner ring and an outer ring. The combination delivers reliable sealing in chemical, acid, alkali, solvent and low-temperature service where standard graphite-filled gaskets may not be suitable.
We supply ASME B16.20 CGI spiral wound gaskets for flat face and raised face flanges, including high-pressure, high-temperature, corrosive and toxic media applications. Custom sizes, OEM private-label packaging, bulk quotations and fast delivery are available for B2B buyers. Send your flange specification today for a firm quotation.
An SS 304 with PTFE filler spiral wound gasket is a semi-metallic gasket made from SS 304 V-shape stainless steel strip and PTFE soft filler. The SS 304 winding provides mechanical strength, elasticity and spring-back under bolt load, while the PTFE filler provides excellent chemical resistance against most acids, alkalis, organic acids, inorganic acids and solvents. The CGI construction adds an inner ring and an outer ring, making the gasket suitable for flat face and raised face flanges, high-pressure service and corrosive or toxic media.
The following values are typical for SS 304 / UNS S30400 austenitic stainless steel used in spiral wound gasket winding tape. The PTFE filler is selected for chemical resistance and low-temperature sealing performance.
| Element | Cr | Ni | C | Mn | Si | P | S |
|---|---|---|---|---|---|---|---|
| Typical value | 18–20% | 8–10.5% | ≤0.08% | ≤2% | ≤0.75% | ≤0.045% | ≤0.03% |
| Property | Typical Value |
|---|---|
| UNS number | S30400 |
| Tensile strength | 550 MPa |
| Yield strength, 0.2% offset | 230 MPa |
| Elongation | 51% |
| Density | 7.93 g/cm³ |
| Hardness | 85 HRB |
| Low-temperature performance | Good at -180°C |
| Design standard | ASME B16.20 |
PTFE filler is chosen when the flange joint must resist aggressive chemicals. It is chemically inert against most acids, alkalis and solvents, and it performs well in low-temperature service. However, the SS 304 winding still has its own limits, especially in chloride-bearing media and strong reducing acids. Use the matrix below as a starting point, then send the exact medium, concentration and temperature for confirmation.
| Medium / Service | Suitability | Notes for Buyers |
|---|---|---|
| Nitric acid ≤65% below boiling temperature | Excellent | PTFE filler and SS 304 winding both perform well in oxidizing acid service. |
| Most alkali solutions | Excellent | PTFE filler provides strong resistance; confirm temperature and concentration. |
| Organic acids | Good to excellent | Performance depends on concentration, temperature and aeration. |
| Inorganic acids | Good, medium dependent | Not all inorganic acids are equal; sulfuric and hydrofluoric acid require review. |
| Solvents | Excellent | PTFE is resistant to most common industrial solvents. |
| Chloride solutions | PTFE filler resistant; SS 304 winding limited | SS 304 can suffer pitting and stress corrosion cracking in chlorides. Consider SS 316L or higher alloy winding. |
| Sulfuric acid | Limited | Not recommended at high concentration or elevated temperature without engineering review. |
| Hydrofluoric acid | Not recommended | Requires special materials and is outside standard SS 304 PTFE gasket service. |
For corrosive or toxic media, the CGI design with an inner ring is preferred because the inner ring supports the winding and reduces the risk of inward buckling. If your medium contains chlorides, send the chloride concentration and operating temperature so we can recommend the correct winding alloy.
The CGI spiral wound gasket uses both an inner ring and an outer ring. This is the construction specified when the joint needs a compression stop, better centering and additional protection for the winding.
Centers the gasket on the flange bolt circle and protects the winding during handling and installation. Standard material is carbon steel painted; SS 304 or SS 316 is available on request.
V-shape SS 304 stainless steel tape provides mechanical strength, elasticity and recovery under thermal cycling.
Soft PTFE filler fills the spaces between the winding turns and provides the chemical sealing barrier.
Acts as a compression stop, prevents inward buckling and reduces turbulence in the bore. Recommended for high-pressure, corrosive and toxic media.
CGI gaskets are suitable for flat face and raised face flanges. They can be specified for high-pressure and high-temperature service, or where corrosive or toxic media are present.
SS 304 with PTFE filler spiral wound gaskets are used across chemical, oil and gas, petrochemical, pharmaceutical, food processing and low-temperature industries.
Reactors, columns, heat exchangers and piping handling acids, alkalis and solvents.
Flanged joints where corrosive or toxic media require a chemical-resistant filler and a supported winding.
Process units where PTFE filler resists aggressive chemicals and the CGI design controls compression.
Clean service flanges where PTFE filler offers chemical inertness and easy cleaning.
Processing and storage equipment where SS 304 durability and PTFE inertness are preferred.
SS 304 maintains good strength and elongation at low temperature, making it suitable for cold service.
To receive a firm quotation, lead time and available samples, send the following five items with your inquiry. If you already have a flange drawing or an existing gasket sample, attach it and we will match it directly.
NPS, DN or specific inner and outer diameters for non-standard joints.
Class 150, 300, 600, 900, 1500, 2500 or PN10 to PN250.
PTFE as standard for chemical service; graphite or vermiculite can be quoted on request.
Carbon steel painted as standard; SS 304 or SS 316 available for corrosive environments.
Order quantity and destination port so we can quote FOB, CIF or freight-inclusive pricing.
Custom sizes, OEM private-label packaging and bulk production are available. If you are not sure whether PTFE, graphite or vermiculite filler is correct for your medium, send the chemical name, concentration and operating temperature and our sales engineers will recommend the right configuration.
Send your flange standard, nominal pipe size, pressure rating, medium, temperature, ring material and quantity. Our sales engineers will reply with a quotation, lead time and available samples.
Address
No 432 Zhenhai Middle Road, Luotuo Street, Zhenhai District, Ningbo City, Zhejiang China
