Barium sulfate-filled PTFE gaskets are made by adding barium sulfate filler to PTFE resin. Barium sulfate is the only filled PTFE material that can handle both strong caustics and hydrofluoric acid (HF) simultaneously, high density, excellent creep resistance, and superior chemical resistance.
It is one of the preferred sealing materials for chlor-alkali, fluorine chemical, pulp and paper, and wastewater treatment industries.
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Problem |
Consequence |
How BaSO₄ Gaskets Solve the Problem |
|
Creep and leakage of PTFE gaskets in strong caustic (NaOH, KOH) service |
Frequent replacement, production interruption, safety risks |
Barium sulfate filling significantly reduces cold flow and improves bolt torque retention. |
|
Frequent failure of seals in chlorine piping |
Leakage, equipment corrosion, safety hazards |
Barium sulfate is a recommended filler material for chlorine service. |
|
Corrosion of glass/silica-filled gaskets in hydrofluoric acid (HF) service |
Gasket failure, equipment damage, personnel safety risk |
Barium sulfate gaskets are suitable for use with up to 48% HF. |
|
Extrusion and deformation of conventional PTFE gaskets under high pressure |
Bolt relaxation, leakage, shutdown |
Density of 2.5 g/cm³; higher compressive strength. |
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Product Form |
Specifications / Description |
|
Sheets |
1500 × 1500 mm |
|
Thickness Range |
1.0 mm – 8.0 mm |
|
Cut Gaskets |
Custom-cut to any flange size |
|
Comparison Item |
BaSO₄ Filled |
Silica Filled |
Glass Microsphere Filled |
Glass Fiber Filled |
|
Strong Caustics (NaOH/KOH) |
★★★★★ Excellent |
★★★☆☆ Limited |
★★★☆☆ Limited |
★☆☆☆☆ Not suitable |
|
Hydrofluoric Acid (HF) |
★★★★★ Suitable (up to 48%) |
❌ NOT compatible |
❌ NOT compatible |
❌ NOT compatible |
|
Chlorine |
★★★★★ Excellent |
★★★★★ Excellent |
★★★★☆ Good |
★★★★☆ Good |
|
Creep Resistance |
★★★★★ Excellent (30% creep relaxation) |
★★★★★ Excellent |
★★★★☆ Good |
★★★★☆ Good |
|
Density |
2.5 g/cm³ |
2.1–2.3 g/cm³ |
1.7–2.0 g/cm³ |
2.2–2.4 g/cm³ |
|
Compressibility |
8–16% |
7–11% |
≥18% |
Moderate |
|
Best For |
Caustics + HF + Chlorine |
Strong acids, solvents |
Low torque, uneven flanges |
High wear, high pressure |
Recommendation: If your operating conditions involve strong alkalis, chlorine gas, or hydrofluoric acid (HF), barium sulfate-filled PTFE is the only material capable of fully handling all three of these harsh media.
|
Comparison Items |
Barium Sulfate PTFE Gasket |
Conventional PTFE Gasket |
|
Density |
2.5 g/cm³ |
2.15–2.20 g/cm³ |
|
Creep Resistance |
★★★★★ Excellent (30% creep relaxation) |
★★☆☆☆ Poor (significant cold flow) |
|
Tensile Strength |
13.2 MPa |
Lower |
|
Caustic Resistance |
★★★★★ Excellent |
★★★☆☆ Moderate |
|
HF Resistance |
★★★★★ Suitable (up to 48%) |
★★★★★ Suitable |
|
Typical Seal Life |
3–5 years |
1–2 years |
|
Material Cost |
30–50% higher |
(Lower) |
Barium sulfate-filled gaskets perform exceptionally well in strongly alkaline media (such as NaOH and KOH), making them the standard choice for industries including chemical processing, chlor-alkali, and papermaking.
These gaskets are suitable for hydrofluoric acid applications at moderate concentrations and temperatures (up to 48% HF). This capability exceeds that of glass fiber- or silica-filled PTFE gaskets; barium sulfate is the only PTFE filler material capable of handling both strong alkalis and HF.
Barium sulfate is a recommended filler material for chlorine service and is widely used in the chlor-alkali industry.
The barium sulfate filler results in a material density of 2.5 g/cm³ and a tensile strength of 13.2 MPa, significantly enhancing resistance to compression and extrusion.
A unique manufacturing process minimizes PTFE cold flow issues, resulting in a creep relaxation of only 30% and excellent bolt torque retention.
FDA 21 CFR 177.1550, TA-Luft (VDI 2440), BAM (oxygen service, up to 260°C/52 bar), ABS, DNV-GL, RoHS, and REACH.
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Parameter |
Parameter / Value |
|
Material |
PTFE + Barium Sulfate (BaSO₄) |
|
Color |
Granite White |
|
Density |
2.5 g/cm³ |
|
Minimum Temperature |
-212°C to -268°C |
|
Maximum Temperature |
260°C (continuous) / 271°C (peak) |
|
Maximum Pressure |
55–103 bar (800–1,500 PSI) |
|
Compressibility (ASTM F36) |
8–16% |
|
Recovery (ASTM F36) |
35% |
|
Creep Relaxation (ASTM F38) |
30% |
|
Tensile Strength (ASTM F152) |
13.2 MPa / 1,920 psi |
|
Sheet Size |
1500 × 1500 mm |
|
Thickness Range |
1.0–8.0 mm |
|
Industry |
Typical Applications |
Why Barium Sulfate (BaSO₄)? |
|
Chlor-Alkali |
Chlorine and caustic soda piping seals |
Material specifically designed for chlorine and strong alkalis |
|
Fluorine Chemicals |
Hydrofluoric acid (HF) piping seals |
The only filled PTFE suitable for handling HF |
|
Pulp & Paper |
Digesters, chemical lines |
Resistant to strong alkalis and chemicals |
|
Chemical & Petrochemical |
Strong caustic piping, toxic chemicals |
Resistant to strong alkalis and corrosion |
|
Wastewater Treatment |
Chemical dosing systems |
Chemical resistant with a long service life |
|
Pharmaceutical |
Sterile equipment seals |
FDA compliant and high purity |
|
Power Generation |
Water treatment, flue gas desulfurization (FGD) |
Corrosion and temperature resistant |
Typical Media: Strong alkalis (NaOH, KOH), chlorine gas, hydrofluoric acid (HF, up to 48%), hydrogen peroxide, sodium hypochlorite, nitric acid, chlorine dioxide, steam, hydrocarbons, refrigerants, etc.
|
Case Studies |
Challenge |
Solution |
Result |
|
Chlor-alkali plant in the USA |
Standard PTFE gaskets in chlorine piping suffered from creep-induced leakage at high temperatures, requiring replacement every six months. |
Replaced with barium sulfate filled PTFE gaskets |
Two years of continuous operation with zero leakage; maintenance costs reduced by 70% |
|
Fluorine chemical plant in Germany |
Seals in hydrofluoric acid (HF) piping frequently failed, posing safety risks. |
Used barium sulfate gaskets |
Seal service life extended threefold; TA-Luft certified |
A: Barium sulfate-filled PTFE gaskets incorporate barium sulfate filler, resulting in higher density (2.5 vs. 2.15–2.20), significantly improved creep resistance (30% reduction in creep relaxation), and higher tensile strength (13.2 MPa). While standard PTFE gaskets offer excellent chemical resistance, they are prone to significant cold flow.
Choose barium sulfate-filled gaskets for: strong alkalis, chlorine gas, hydrofluoric acid (HF), toxic chemicals, and high-pressure applications.
Choose standard PTFE gaskets for: general chemicals, non-critical applications, and lower-cost requirements. Although barium sulfate-filled gaskets are 30–50% more expensive, they offer a significantly longer sealing service life, resulting in a lower total cost of ownership.
A: The key difference lies in HF compatibility. Both glass-fiber-filled PTFE and silica-filled PTFE are incompatible with hydrofluoric acid (HF); the fillers react with HF, leading to gasket failure.
Barium sulfate-filled gaskets are suitable for service conditions involving HF concentrations of up to 48%. Furthermore, barium sulfate is the only filled PTFE material capable of handling both strong alkalis and HF.
If your application involves strong alkalis, chlorine gas, or HF, barium sulfate is the preferred choice.
For specific selection recommendations, please provide details regarding the medium, temperature, and pressure.
A: Yes. Barium sulfate-filled gaskets comply with FDA 21 CFR 177.1550 requirements for food contact and are suitable for the food, pharmaceutical, and drinking water industries.
The PTFE material is non-toxic, tasteless, and odorless, and does not contaminate the medium. Please specify the FDA-compliant grade when ordering.
A: Temperature: Continuous use from -200°C to +260°C (peaks up to 271°C).
Pressure: Up to 55–103 bar (800–1,500 PSI), depending on gasket thickness and flange design.
Chemical Resistance: pH 0–14; especially recommended for media such as strong alkalis, chlorine gas, and HF.
For precise specifications, please provide your operating parameters, and we will perform the necessary calculations to offer a recommendation.
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