What is a Floating Ball Valve: Factory Comprehensive Guide

What is a Floating Ball Valve

A floating ball valve is one of the types of ball valves, and the corresponding one is trunnion mounted ball valve. The features an unsupported ball held only between two sealing seats. The stem connects flexibly to the ball, allowing it to “float.” Under medium pressure, the ball displaces toward the downstream seat, creating a tight seal on the outlet side.

Key Components

 • Ball Valve Body/Bonnet: The main pressure-bearing parts of the valve

• Ball Valve Ball: Free-moving sphere with bore

• Valve Stem: Transmits torque to the ball

• Seats: Dual sealing surfaces

• Seals: PTFE or reinforced composites

Floating Ball Valve Structural Diagram-NSW

 

Technical Specifications

Parameter Range
Size (DN) 15 – 800
Pressure (PN) 1.6MPa – 32.0MPa
Connections Threaded (int/ext), Flanged, Welded, Wafer, Clamp
Temperature -196°C to 550°C
Actuation Manual/Pneumatic/Electric
Materials Cast/Carbon/Forged Steel, Stainless
Standards GB, DIN, API, ANSI

Engineered Structural Features of Floating Ball Valve

1. Dual-Sealing Seat Design

Proprietary low-friction seat machining reduces operating torque while ensuring zero-leakage performance through bi-directional sealing.

2. Alignment-Proof Stem

The flats-cut stem prevents handle misalignment. Parallel handle = Open; Perpendicular handle = Closed.

3. Safety Locking Holes

Dual lock holes at full open/closed positions prevent accidental actuation—critical for hazardous pipelines.

4. Blowout-Proof Stem

An integrated shoulder prevents stem ejection during overpressure events, maintaining seal integrity.

5. Anti-Static System

Grounding springs discharge friction-generated static electricity—essential for flammable media like LNG or propane.

Anti-static design of ball valve

6. Fire-Safe Construction

Metal-to-metal backup seals engage during fires:

• Ball/body contact replaces burned seats

• Graphite fire seals expand to block leaks

• API 607/6FA compliant 

Ball valve fire protection structure

7. Zero-Leakage Body Joint

Interlocking flange design eliminates gasket dependency, preventing external leakage under extreme conditions.

Industrial Applications

• General Service: Water, solvents, acids

• Critical Media: Oxygen, H₂O₂, methane

• Harsh Environments:

Petrochemical plants

Natural gas pipelines (H₂S resistant)

Cryogenic systems

High-corrosion slurry transport

Floating Ball Valves Advantages vs. Limitations

Pros:

✓ Compact maintenance-friendly design

✓ Bubble-tight sealing

✓ Low flow resistance

✓ 90° quick operation

Cons:

✘ Seat friction limits high-P/T use

✘ Not for slurries (risk of groove clogging)

✘ Requires skilled installation

 

Installation & Maintenance Protocols

Installation Requirements

• Mount horizontally on level surfaces

• Avoid flow turbulence near ball

• Ensure unobstructed access

Maintenance Checklist

• Quarterly: Inspect ball/scraper rings for erosion

• Annually:

Lubricate stem bearings

Verify torque values

Test emergency seals

• Post-shutdown: Clean cavity to prevent crystallized deposits

 

Floating vs. Trunnion Mounted Ball Valves: Technical Comparison

Aspect Floating Type Trunnion Mounted Type
Sealing Principle Media pressure pushes ball to seat Springs force seats toward ball
Mounting Single top stem Dual trunnion-supported
Pressure Rating ≤Class 1500 (DN300 max) Up to Class 2500 (DN1500+)
Applications Low-mid pressure systems Pipeline mainlines (e.g. West-East Gas Project)

Selection Guidance

Choose floating valves for cost-effective, compact solutions under Class 600. Opt for trunnion-mounted valves when handling:

• Pressures >Class 900

• Frequent cycling operations

• Cryogenic or erosive media


Post time: Dec-10-2024