VIIPLUS SOLUTIONS® Advanced Bearing Technology · Engineered for Reliability
SS316 · PTFE Composite

SS316 Stainless Steel–PTFE (Fabric) Composite Bearings for Double Offset Butterfly Valves

Low-Friction Surface with Structural Strength
📄 Description Wrapped Composite Bearing

VIIPLUS SOLUTIONS® Stainless Steel PTFE Composite Bearings combine a reinforced PTFE sliding layer, glass fiber reinforcement, and a stainless steel backing to deliver the strength and dimensional stability of a metallic structure together with the low‑friction and wear‑resistant characteristics of advanced composite bearing materials.

Composite Bearing Material · PTFE Glass Fiber Composite · Metal‑Backed PTFE Composite Sliding Bearing
Engineered for double offset butterfly valves, pumps, marine, energy, and process industry applications.

🎯 Purpose & Operating Principle

VIIPLUS SOLUTIONS® Stainless Steel PTFE Composite Bearings utilize a high‑performance woven PTFE and glass fiber composite layer bonded to a metallic backing. This advanced material system provides exceptional resistance to corrosive media, aggressive chemicals, cyclic fatigue, and impact loading. Designed for dry‑running and maintenance‑free operation, it delivers reliable low‑friction performance without requiring additional lubrication.

🔧 Applications Valve Bearing System

Suitable for

  • Industrial Valves
  • Heavy‑Duty Actuators
  • Hydraulic Equipment
  • Rotating & Oscillating Machinery
  • Low‑Speed, Heavy‑Load Applications

Designed for

  • Double Offset Butterfly Valves
  • Triple Offset Butterfly Valves
  • Ball Valves · Gate Valves
  • Hydropower Equipment
  • Lubricant Films Cannot Be Maintained

Ideal for

  • Dry Running Conditions
  • Intermittent Operation
  • High Humidity Environments
  • Corrosive Service Conditions
🧪 Chemical & Mechanical Requirements ASTM

Table 1 — Chemical Composition (SS316)

Grade C %Si %Mn % S %P % Cr %Ni %Mo % N %Cu %
SS316 Stainless Steel Min 16.010.02.0
Max0.080.752.000.0300.045 18.014.03.00.10

Table 2 — Mechanical Properties (SS316)

Grade Heat Treatment / Supply SIZE TS Min, MPa (ksi) YS Min, MPa (ksi) EL % GL 50mm, min Hardness
SS 316 Stainless Steel Annealed ALL 515 (75) 205 (30) 40
Note:
1. Chemical composition shall meet the limits in Table 1. Test method per applicable ASTM standard.
2. Mechanical properties shall meet Table 2. Test method per applicable ASTM standard.
3. Yield testing by 0.2% offset method for ASTM standard.
⚙️ Characteristics & Construction

VIIPLUS SOLUTIONS® Stainless Steel PTFE Composite Bearings are manufactured from an advanced composite system consisting of a reinforced PTFE sliding layer bonded to a stainless steel backing. The engineered PTFE matrix, enhanced with glass fibers and wear‑resistant fillers, delivers strong chemical resistance, corrosion protection, fatigue endurance under cyclic and shock loading, and impact strength — while eliminating the need for external lubrication.

The thin‑wall composite construction combines the structural strength, rigidity, and dimensional stability of stainless steel with the low coefficient of friction and advanced tribological performance of reinforced PTFE. This optimized material system enables reliable operation under dry‑running and boundary lubrication conditions, making it well suited for maintenance‑free industrial applications.

🧬 Material Structure — Self‑Lubricating Sliding Layer
Backing: ASTM A240 Type 316 / 304 Stainless Steel Sliding Layer: PTFE · Glass Fiber · Wear‑Resistant Fillers · Solid Lubricants
📊 Technical Characteristics
Coefficient of Friction0.05 – 0.10
Max Static Load345 MPa (50,000 psi)
Recommended Working Load≤140 MPa
Operating Temperature−200°C to +180°C
LubricationMaintenance‑Free
Electrical ConductivityNon‑Conductive
Magnetic PropertiesNon‑Magnetic
Corrosion ResistanceExcellent
📌 Temperature note: Long‑term continuous operation recommended ≤150°C; 180°C is the short‑term maximum.
🔧 Shaft mating recommendation: Shaft hardness ≥ HB 250, surface roughness Ra 0.4–0.8 μm for optimal tribological performance.
✅ Why Use Stainless Steel PTFE Composite Bearings?

When to Consider

  • Corrosive Media Are Present
  • Seawater Systems · Offshore Equipment
  • LNG Facilities · Sour Gas Applications
  • Chemical Processing Plants
  • Lubricant Contamination Is Unacceptable
  • Water Treatment · Food & Pharma Machinery
  • Offshore Platforms · Subsea Equipment
  • Critical Valve Systems · High Impact Loads

Key Benefits

  • Self‑Lubricating Operation
  • Corrosion Resistance
  • Reduced Valve Operating Torque
  • Extended Service Life
  • Resistance to Fretting and Brinelling
  • Dimensional Stability Under Load
  • Reliable Performance in Sour Service Environments
🌀 Double Offset Butterfly Valve Bearing Solution

In Double Offset Butterfly Valves (DOBFV), bearing performance directly influences: Operating Torque · Shaft Alignment · Seat Integrity · Service Life · Maintenance Intervals. VIIPLUS SOLUTIONS® Stainless Steel PTFE Composite Bearings are engineered to support both upper and lower valve shaft positions, providing stable shaft guidance while minimizing friction and wear throughout repeated opening and closing cycles.

316 Stainless Steel + PTFE/Glass Fiber Composite Bearing System

Optimal balance between Load Capacity · Corrosion Resistance · Self‑Lubrication · Long‑Term Reliability. By reducing friction, eliminating lubrication requirements, and extending service life, VIIPLUS SOLUTIONS® bearing systems help improve valve reliability while lowering total lifecycle operating costs.

🧵 VIIPLUS PTFE Glass Fiber Composite Bearing Material Heavy‑Duty Sliding

VIIPLUS PTFE Glass Fiber Composite Bearing Material is a metal‑backed composite bearing material designed for low‑speed, high‑load, and oscillating sliding applications. It is commonly applied in industrial valves, offshore equipment, oil and gas processing systems, hydraulic equipment, pumps, marine engineering, and other machinery where external lubrication is limited or maintenance intervals are extended.

The composite structure combines a PTFE‑based sliding layer, woven glass fiber reinforcement, engineered wear‑resistant fillers, a high‑strength bonding resin, and a metallic backing. This multilayer construction provides stable friction characteristics, wear resistance, mechanical support, and dimensional stability under demanding operating conditions.

📐 Material Construction
LayerMaterialFunction
Sliding Layer PTFE + Woven Glass Fiber + Wear‑Resistant Fillers Low friction, dry‑running, wear resistance, chemical resistance
Bonding Layer Thermosetting Resin Bonds composite liner to metallic backing; maintains structural integrity
Backing Layer Stainless Steel (304/316) or Carbon Steel Mechanical strength, rigidity, dimensional stability, load support

The resulting construction is a metal‑backed PTFE glass fiber composite bearing material, rather than a solid PTFE bearing.

⚖️ Comparison — VIIPLUS vs. Conventional Metal‑Polymer
FeatureVIIPLUS PTFE Glass Fiber CompositeConventional Metal‑Polymer Bearing
Sliding LayerPTFE + Woven Glass Fiber CompositePTFE + Sintered Bronze
Backing MaterialStainless Steel or Carbon SteelLow Carbon Steel
Load CapabilitySuitable for heavy‑load applicationsSuitable for general industrial
Impact ResistanceReinforced composite structureStandard construction
Corrosion ResistanceDepends on backing selectionDepends on backing selection
Typical ApplicationsValves, offshore, hydraulic, oscillatingGeneral rotary sliding

Conventional metal‑polymer bearings are widely used for rotary motion in general industrial equipment, while PTFE glass fiber composite bearing materials are commonly selected for oscillating motion, pivoting movement, or extended maintenance intervals.

🏭 Typical Valve Applications

In double offset butterfly valves and similar valve assemblies, composite bearing materials may be used for:

Upper Shaft Bearings Lower Shaft Bearings Composite Thrust Washers

Engineering Functions

  • Supporting valve shaft movement
  • Reducing sliding friction
  • Minimizing metal‑to‑metal contact
  • Operating without grease lubrication
  • Supporting long maintenance intervals

Compatibility

  • Corrosion‑resistant valve assemblies
  • Sour service or corrosive environments
  • Applicable industry standards & project specs
⚡ Engineering Features