Key Product Features
- Metal-to-metal sealing design for severe service isolation
- Hard-faced ball and seat surfaces for abrasion and temperature resistance
- Suitable for selected high-temperature, steam, slurry, powder and particle-containing media
- Floating-ball or trunnion-mounted construction according to size, pressure and torque
- Full-bore or reduced-bore flow passage
- Flanged, socket-weld, butt-weld and other connection options
- Manual gearbox, pneumatic, electric or hydraulic operation
- Fire-safe, anti-static, low-emission and NACE options available only when supported by the selected design
- Leakage class, coating, hardness and torque must be confirmed before quotation
Product Configuration
| Configuration Item | Common Configuration | Optional Configuration |
|---|---|---|
| Valve Design | Two-way on-off ball valve | Floating-ball, trunnion-mounted or top-entry structure |
| Seat Type | Metal seat | Bi-directional or uni-directional sealing, depending on design |
| Sealing Surface | Hard-faced ball and seat | Coating or overlay selected by medium and temperature |
| Body Construction | Two-piece or split-body construction | Three-piece, forged, cast or top-entry construction |
| End Connection | Flanged | Butt weld, socket weld or project-specific connection |
| Operation | Gearbox operation | Pneumatic, electric or hydraulic actuator |
Technical Specifications
| Specification Item | Typical / Available Options |
|---|---|
| Product Type | Metal seated ball valve / hard sealed ball valve |
| Primary Function | On-off isolation for severe service pipelines |
| Ball Support | Floating ball or trunnion mounted, depending on size, pressure and torque |
| Body Construction | Two-piece, three-piece, split-body, forged, cast or top-entry design |
| Size Range | According to selected product series and approved drawing |
| Pressure Rating | According to body material, end connection, temperature and approved pressure-temperature rating |
| Body Material | WCB, A105, LCB, LF2, CF8, CF8M, F304, F316, alloy steel, duplex stainless steel or project-specified material |
| Ball Material | Stainless steel, alloy steel, duplex stainless steel or hard-faced base material |
| Seat Material | Metal seat with hard-facing or coating according to service condition |
| Hard-Facing / Coating | Tungsten carbide, chromium carbide, Stellite-type overlay, nitriding or project-specific surface treatment |
| Stem Material | Stainless steel, alloy steel, duplex stainless steel or project-specified material |
| Packing | Graphite, flexible graphite or low-emission packing system |
| Body Seal | Graphite, spiral-wound gasket or project-specific high-temperature seal |
| Port Design | Full bore or reduced bore |
| End Connection | Flanged, butt weld, socket weld or project-specific connection |
| Operation | Gearbox, pneumatic actuator, electric actuator or hydraulic actuator |
| Design Reference | API 608, API 6D, ASME B16.34 or approved project specification where applicable |
| Testing Reference | API 598, API 6D, EN 12266 or approved inspection specification where applicable |
| Typical Media | Steam, thermal oil, slurry, powder, ash, catalyst fines, abrasive media, high-temperature gas and selected chemical service |
Technical note: Do not publish fixed maximum temperature, pressure, leakage class or coating hardness until the selected product datasheet, coating specification and approved drawing are confirmed. Metal seated ball valves are highly dependent on the actual service condition.
Metal Seat vs Soft Seat Ball Valve
The key difference is the sealing pair. A soft-seated ball valve uses polymer seats such as PTFE, RPTFE, PEEK or PPL. A metal seated ball valve uses a metal ball and metal seat with precision lapping and hard-faced surfaces. This makes it more suitable for severe service, but it also changes leakage performance, torque and cost.
| Comparison Item | Soft Seated Ball Valve | Metal Seated Ball Valve |
|---|---|---|
| Sealing Material | PTFE, RPTFE, PEEK, PPL or other polymer seat | Hard-faced metal ball and metal seat |
| Shutoff Performance | Usually tighter shutoff under clean service conditions | Leakage class must be specified; not automatically bubble-tight |
| Temperature Resistance | Limited by polymer seat material | Better for selected high-temperature service |
| Abrasive Media | Seat can be damaged by particles | Better resistance when hard-facing is properly selected |
| Operating Torque | Generally lower | Generally higher and requires careful actuator sizing |
| Cost | Usually lower | Usually higher due to coating, lapping and testing requirements |
| Typical Use | Clean water, oil, gas, air and general process media | Steam, slurry, powder, catalyst, ash, thermal oil and severe service |
For general high-pressure isolation with soft or special seats, compare our High Pressure Ball Valve. For corrosion-resistant stainless steel construction, see the 316 Stainless Steel Ball Valve.
Hard-Faced Ball and Seat Design
The performance of a metal seated ball valve depends heavily on the ball and seat sealing surfaces. The ball surface and seat surface must be compatible in hardness, coating method, surface finish and lapping quality. If the coating is too soft, too brittle, poorly bonded or unsuitable for the medium, the valve may lose sealing performance quickly.
| Design Point | Why It Matters |
|---|---|
| Coating / Overlay Type | Determines resistance to abrasion, erosion, temperature and chemical attack. |
| Surface Hardness | Helps resist scratching, particle cutting and repeated cycling damage. |
| Lapping Quality | Affects contact pattern, leakage performance and initial sealing reliability. |
| Seat Spring Load | Controls sealing force and affects torque under pressure. |
| Thermal Expansion | Important for high-temperature service where ball, seat and body expand differently. |
| Flow Direction | Some metal seated designs are preferred for one-way sealing; bidirectional performance must be confirmed. |
Material and Coating Options
| .omponent | Common Options | Selection Consideration |
|---|---|---|
| Body | WCB, A105, LCB, LF2, CF8M, F316, alloy steel or duplex stainless steel | Pressure, temperature, corrosion, impact toughness and welding requirement |
| Ball | Stainless steel, alloy steel or duplex stainless steel with hard-facing | Surface hardness, coating bond, corrosion resistance and erosion resistance |
| Seat | Metal seat with hard-facing, spring-loaded or fixed seat design | Leakage class, pressure, temperature, particle size and cycling frequency |
| Coating | Tungsten carbide, chromium carbide, Stellite-type alloy or nitrided surface | Abrasion, erosion, thermal cycling, corrosion and cost |
| Stem | SS316, 17-4PH, duplex stainless steel or alloy steel | Torque transmission, corrosion, temperature and mechanical strength |
| Packing | Graphite, flexible graphite or low-emission packing | High temperature, stem cycling and emission requirement |
| Body Seal | Graphite, spiral-wound gasket or high-temperature seal | Body construction, fire-safe requirement and thermal cycling |
Typical Applications
Typical ApplicationsMetal seated ball valves are selected where soft seats may be damaged by temperature, particles or severe operating conditions. Common service areas include:
- High-temperature steam and condensate isolation
- Thermal oil and heat transfer systems
- Coal chemical, ash handling and powder conveying lines
- Catalyst fines, refinery slurry and particle-containing process media
- Mining slurry and abrasive industrial service
- High-temperature gas and process vapor isolation
- Severe service chemical pipelines after material review
- Power plant, petrochemical and refinery auxiliary systems
For broader application planning, review our Ball Valve Applications guide and Ball Valve category.
Application Limits
- Metal seated construction does not automatically mean zero leakage.
- The required leakage class must be specified before quotation.
- Operating torque is normally higher than soft-seated ball valves.
- Actuator sizing should be based on actual differential pressure and service condition.
- Continuous throttling may still cause erosion, vibration and seat damage.
- Large hard particles, sharp solids or very high velocity may require a special severe-service design.
- Corrosive and abrasive media together require both corrosion and erosion review.
- High temperature service requires suitable body material, packing, body seal and bolting.
- Oxygen, hydrogen, sour gas and toxic media require dedicated material and safety review.
Connection and Operation Options
| Option | Main Advantage | Typical Use |
|---|---|---|
| Flanged Metal Seated Ball Valve | Removable bolted connection for inspection and replacement | Industrial pipelines and severe service process lines |
| Butt-Weld Metal Seated Ball Valve | Permanent welded connection with fewer external leak paths | High-temperature, steam and process pipelines |
| Socket-Weld Metal Seated Ball Valve | Compact welded joint for smaller severe-service lines | Drain, vent, steam, thermal oil and small process piping |
| Gearbox Operation | Reduces manual effort for higher torque valves | Medium and larger metal seated ball valves |
| Pneumatic Actuator | Fast remote operation | Automated severe-service shutoff |
| Electric Actuator | Remote control where air supply is not available | Process automation and utility systems |
| Hydraulic Actuator | High torque output | Large-size, high-pressure or emergency shutdown service |
For removable pipeline installation, see our Flanged Ball Valve. For severe high-pressure isolation, compare the High Pressure Ball Valve.
Inspection and Documentation
| Inspection / Document | Purpose |
|---|---|
| Material Test Certificate | Confirms body, ball, stem, seat, bolting and pressure-containing material grades. |
| PMI | Verifies alloy chemistry when specified. |
| Hardness Test | Checks hard-facing or coating hardness according to purchase specification. |
| Coating / Overlay Inspection | Checks coating integrity, surface condition and bonding quality when required. |
| Dimensional Inspection | Checks end connection, bore, face-to-face or end-to-end length and actuator interface. |
| Shell Pressure Test | Verifies pressure-containing body integrity. |
| Seat Leakage Test | Confirms shutoff performance under the specified leakage class and test condition. |
| Operation / Torque Test | Checks valve movement and supports gearbox or actuator sizing. |
| NDE | Radiographic, ultrasonic, magnetic-particle or liquid-penetrant examination when specified. |
| Fire-Safe / Anti-Static Evidence | Provided only when the selected valve model has applicable design or test evidence. |
Export packing should protect machined sealing surfaces, ball surfaces, hard-faced seats, connection ends and actuator interfaces. Metal seated ball valves should be packed with port protectors, internal support, moisture protection, anti-rust treatment and reinforced plywood cases according to valve size, surface treatment and transport method.
Information Required for Valve Selection
- Valve size and quantity
- Working pressure, design pressure and pressure class
- Working temperature and design temperature
- Medium name, composition, concentration and phase
- Particle type, particle size, solid content and flow velocity
- Clean fluid, slurry, powder, catalyst, ash, steam or thermal oil service
- Required leakage class or acceptance standard
- Required coating, overlay, hardness or surface treatment
- Body, ball, seat, stem, packing and bolting materials
- Floating-ball, trunnion-mounted or top-entry construction
- Full-bore or reduced-bore requirement
- Flanged, socket-weld, butt-weld or other connection type
- Manual gearbox, pneumatic, electric or hydraulic operation
- Fire-safe, anti-static, NACE, low-emission, oxygen, hydrogen or sour-service requirements
- Testing, NDE, hardness testing, coating inspection and third-party inspection requirements
FAQ
1. What is a metal seated ball valve used for?
A metal seated ball valve is used for on-off isolation in high temperature, abrasive, steam, slurry, powder, thermal oil and severe industrial service where soft seats may be damaged by heat, particles or erosion.
2. Is a metal seated ball valve zero leakage?
Not automatically. Metal seated ball valves normally require a specified leakage class or acceptance standard. They are more resistant to heat and abrasion than soft-seated designs, but shutoff performance depends on seat design, lapping quality, coating, pressure and test requirement.
3. What is the difference between soft seat and metal seat ball valves?
A soft-seated ball valve uses polymer seats such as PTFE, RPTFE, PEEK or PPL. A metal seated ball valve uses hard-faced metal sealing surfaces. Soft seats usually provide tighter shutoff in clean service, while metal seats are preferred for high temperature, abrasive and severe service conditions.
4. Why is actuator sizing important for metal seated ball valves?
Metal seated ball valves usually have higher operating torque than soft-seated valves because the sealing surfaces are metal-to-metal. Differential pressure, temperature, particles, seat load and coating friction can all affect torque, so gearbox or actuator sizing should be confirmed from the actual service condition.
5. What information is needed for quotation?
For quotation, provide valve size, pressure, temperature, medium, particle content, leakage class, body material, coating requirement, connection type, operation method and testing documents. For severe service, particle size, solid content, flow velocity and cycling frequency are especially important.