This product page covers fully welded ball valve configurations rather than one fixed dimensional model. Depending on valve size, pressure, medium and installation condition, the valve may use floating-ball or trunnion-mounted construction, full-bore or reduced-bore design, flanged or butt-weld ends, extended stem, drain and vent connections, anti-corrosion coating and actuator options. Final configuration must be confirmed from the approved drawing and project specification.
Key Product Features
- Fully welded body structure with reduced external body-joint leakage paths
- Floating-ball or trunnion-mounted design according to valve size and pressure
- Full-bore or reduced-bore flow passage
- Flanged, butt-weld or project-specific end connections
- Extended stem option for buried service, insulated pipelines or remote operation
- Drain, vent, sealant injection and cavity relief options available by selected model
- Manual gearbox, pneumatic, electric or hydraulic operation
- External coating, insulation jacket or corrosion protection options for buried or heating service
- API 6D, fire-safe, NACE, DBB or EN 488 requirements available only when specified and supported by the selected design
Product Configuration
| Configuration Item | Common Configuration | Project Options |
|---|---|---|
| Body Structure | Fully welded body | Welded body with forged, cast or fabricated components |
| Ball Support | Floating ball for selected smaller sizes | Trunnion-mounted design for larger or higher-pressure service |
| Bore Type | Full bore or reduced bore | Piggable bore only when confirmed by drawing |
| End Connection | Butt-weld or flanged ends | RTJ flange, extended weld ends or project-specific connection |
| Installation | Aboveground pipeline installation | Buried service, insulated pipeline or district heating network |
| Operation | Lever or gearbox | Extended stem, pneumatic, electric or hydraulic actuator |
Technical Specifications
| Specification Item | Typical / Available Options |
|---|---|
| Product Type | Fully welded ball valve / welded body ball valve |
| Primary Function | On-off isolation for gas, heating, oil, utility and pipeline service |
| Body Construction | Fully welded body structure |
| Ball Support | Floating ball or trunnion mounted, depending on selected size and pressure |
| 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 | Carbon steel, stainless steel, low-temperature steel, alloy steel or project-specified material |
| Ball Material | Stainless steel, coated stainless steel, alloy steel or project-specified material |
| Stem Material | Stainless steel, alloy steel, duplex stainless steel or project-specified material |
| Seat Material | PTFE, RPTFE, PEEK, PCTFE, metal seat or project-specified seat material |
| Packing | PTFE, graphite, flexible graphite or low-emission packing system |
| End Connection | Butt weld, flanged or project-specific pipeline connection |
| Stem Option | Standard stem or extended stem |
| Operation | Lever, gearbox, pneumatic actuator, electric actuator or hydraulic actuator |
| Design Reference | API 6D, ASME B16.34, EN 488 or approved project specification when applicable |
| Testing Reference | API 598, API 6D, EN 12266 or approved inspection specification where applicable |
| Typical Media | Natural gas, city gas, heating water, hot water, oil, thermal utilities and selected process fluids |
Technical note: Do not publish a fixed maximum pressure, temperature, buried-service depth, service life or standard compliance unless it is confirmed from the selected product datasheet, approved drawing and project specification.
Fully Welded Body vs Butt Weld End Connection
A fully welded ball valve refers to the welded valve body structure. A butt weld ball valve refers to the pipeline end connection. These two terms are related but not identical. A valve can have a fully welded body and flanged ends, or a fully welded body and butt-weld ends.
| Term | What It Describes | Why It Matters |
|---|---|---|
| Fully Welded Body | The valve body shell is welded instead of bolted together. | Reduces external leakage paths from body joints. |
| Butt Weld Ends | The valve ends are prepared for welding directly to the pipeline. | Creates a permanent pipeline connection. |
| Flanged Ends | The valve connects to pipeline flanges with bolts and gaskets. | Allows easier valve removal and replacement. |
For welded-end connection selection, compare the Butt Weld Ball Valve. For removable bolted pipeline installation, see the Flanged Ball Valve.
Fully Welded Body Design
The fully welded body structure removes conventional bolted body joints. This can reduce external leakage risk and make the valve compact for pipeline, gas and heating service. However, it also means the body is generally not designed for field disassembly. Seat, ball and internal maintenance must be considered before selection.
| Design Point | Selection Meaning |
|---|---|
| Welded Body Shell | Reduces body joint leakage paths compared with bolted split-body construction. |
| Non-Disassemblable Body | Internal repair normally cannot be done by opening the valve body in the field. |
| Compact Structure | Useful for buried pipelines, heating networks and pipeline stations. |
| Seat Life | Seat material and service condition must be reviewed carefully because body disassembly is limited. |
| Weld Quality | Body weld inspection and pressure testing are important for project acceptance. |
Floating and Trunnion-Mounted Options
Floating-ball fully welded valves are often used in smaller sizes and suitable pressure ranges. Trunnion-mounted fully welded valves are commonly selected for larger sizes, higher pressure, pipeline service and buried applications where lower operating torque and stronger ball support are required.
| Design Type | Main Advantage | Typical Use |
|---|---|---|
| Floating Fully Welded Ball Valve | Compact structure for smaller pipeline and utility service | Gas, heating, water and utility isolation in selected sizes |
| Trunnion-Mounted Fully Welded Ball Valve | Lower operating torque and stronger support for larger valves | Natural gas, pipeline, buried service and high-pressure isolation |
| Extended Stem Fully Welded Ball Valve | Allows operation above ground or above insulation level | Buried pipelines, district heating and insulated service |
For larger pressure-rated pipeline isolation, compare our Forged Trunnion Ball Valve. Additional ball valve structures are listed in the Ball Valve category.
Buried Service and Extended Stem Options
Fully welded ball valves are commonly considered for buried service because their welded body structure is compact and reduces body-joint leakage paths. For buried installation, the valve should be reviewed as part of the complete pipeline system, not only as a standalone valve.
| Buried Service Item | Why It Matters |
|---|---|
| Extended Stem Length | Determines operating height above ground or inside the valve chamber. |
| Stem Protection | Protects the operating extension from soil, water, corrosion and mechanical damage. |
| Drain and Vent Arrangement | Required when body cavity draining, venting or testing is specified. |
| External Coating | Protects the valve body from soil corrosion and buried pipeline environment. |
| Cathodic Protection Compatibility | May be required for buried steel pipeline systems. |
| Operation Method | Gearbox, T-key, extension stem or actuator interface must be defined before production. |
Materials and Sealing Options
| Component | Common Options | Selection Consideration |
|---|---|---|
| Body | Carbon steel, stainless steel, low-temperature steel or alloy steel | Pressure, temperature, corrosion, welding requirement and buried-service condition |
| Ball | Stainless steel, coated stainless steel or project-specified material | Corrosion resistance, hardness, surface finish and sealing performance |
| Stem | Stainless steel, alloy steel or project-specified material | Torque transmission, corrosion resistance and extended-stem design |
| Seat | PTFE, RPTFE, PEEK, PCTFE or metal seat | Pressure, temperature, gas service, heating water chemistry and leakage requirement |
| Packing | PTFE, graphite, flexible graphite or low-emission packing | Stem sealing, temperature, cycling and fire-safe requirement |
| Body Seal | Welded body structure with internal sealing arrangement according to design | Body construction, pressure cycling and service life requirement |
| External Coating | Epoxy, polyurethane, FBE, PE jacket or project-specific coating | Buried service, soil corrosion, heating network or pipeline coating specification |
Connection and Operation Options
| Option | Main Advantage | Typical Use |
|---|---|---|
| Butt-Weld Fully Welded Ball Valve | Permanent pipeline connection with reduced external joint leakage paths | Gas, oil, heating and buried pipeline service |
| Flanged Fully Welded Ball Valve | Removable pipeline connection while keeping welded valve body structure | Aboveground pipeline stations and equipment isolation |
| Extended Stem Design | Allows operation above ground or insulation level | Buried service and district heating systems |
| Gearbox Operation | Reduces manual effort for larger valves | Medium and large pipeline valves |
| Electric Actuator | Remote operation where automation is required | Heating networks, utility lines and pipeline stations |
| Pneumatic / Hydraulic Actuator | Fast operation or high torque output | Pipeline isolation, ESD and high-pressure service |
Typical Applications
Fully welded ball valves are selected where compact construction, pipeline integrity and reduced external body-joint leakage risk are important. Common service areas include:
- Natural gas transmission and distribution pipelines
- City gas and fuel gas networks
- District heating and hot-water pipelines
- Buried pipeline isolation points
- Oil and refined product pipeline systems
- Pipeline block valve stations
- Thermal utility and plant service lines
- Insulated pipelines and difficult-access installations
For oil and gas pipeline projects, compare the API 6D Ball Valve. For high-pressure isolation, see the High Pressure Ball Valve. For fire-tested service, compare the Fire Safe Ball Valve.
Application Limits
- Fully welded body construction does not mean the valve is always API 6D, fire-safe, DBB or NACE compliant.
- The valve body is generally not designed for field disassembly.
- Seat material and service condition must be reviewed carefully because internal maintenance is limited.
- Buried service requires coating, stem extension, corrosion protection and operation method confirmation.
- Full bore does not automatically mean piggable; bore and transition must be confirmed by drawing.
- Continuous throttling may damage seats and is not recommended for standard fully welded ball valves.
- Heating systems require confirmation of water chemistry, temperature, pressure and insulation requirements.
- Hydrogen, sour gas, oxygen, toxic gas and special chemical service require dedicated material and safety review.
Inspection and Documentation
| Inspection / Document | Purpose |
|---|---|
| Material Test Certificate | Confirms pressure-containing and wetted component material grades. |
| Weld Procedure / Weld Record | Supports traceability of welded body construction when required. |
| NDE | RT, UT, MT or PT inspection for body welds or pressure-containing parts when specified. |
| Dimensional Inspection | Checks bore, end connection, end-to-end length, stem extension and actuator interface. |
| Shell Pressure Test | Verifies pressure-containing body integrity. |
| Seat Leakage Test | Confirms shutoff performance under specified test conditions. |
| Coating Inspection | Checks coating thickness, holiday detection or surface preparation when specified. |
| Torque / Operation Test | Confirms smooth operation and supports gearbox or actuator sizing. |
| Fire-Safe / NACE / EN 488 Evidence | Provided only when the selected model and project requirement support the certification. |
| Final Data Book | Collects drawings, MTCs, weld records, inspection reports, test records and certificates. |
Export packing should protect weld ends, flange faces, coating surfaces, stem extension, actuator interfaces and valve bores. Fully welded valves can be supplied with end protectors, anti-rust treatment, coating protection, moisture-resistant wrapping, foam separation and reinforced export cases according to valve size and transport method.
Information Required for Valve Selection
- Valve size and quantity
- Medium: natural gas, city gas, heating water, oil, thermal utility or special service
- Working pressure, design pressure and pressure class
- Working temperature and design temperature
- Aboveground, buried, insulated or district heating installation
- Floating-ball or trunnion-mounted construction
- Full-bore, reduced-bore or piggable bore requirement
- Flanged, butt-weld or project-specific end connection
- Required stem extension length and operation method
- Drain, vent, sealant injection or cavity relief requirement
- Body, ball, stem, seat, packing and coating materials
- External coating, insulation jacket or corrosion protection requirement
- API 6D, EN 488, fire-safe, NACE, DBB or low-emission requirement if applicable
- Testing, NDE, coating inspection, third-party inspection and final documentation requirements
FAQ
1. What is a fully welded ball valve?
A fully welded ball valve is a ball valve with a welded body structure instead of a conventional bolted split body. This reduces external leakage paths from body joints and is commonly used in gas, heating, oil, buried pipeline and utility service.
2. Is a fully welded ball valve the same as a butt weld ball valve?
No. Fully welded describes the valve body construction. Butt weld describes the pipeline end connection. A fully welded ball valve may have butt-weld ends, flanged ends or other project-specific end connections.
3. Can a fully welded ball valve be repaired in the field?
The welded body is generally not designed to be opened in the field like a bolted split-body valve. Seat life, medium cleanliness, operating conditions and maintenance strategy should be reviewed before selecting a fully welded design.
4. Can a fully welded ball valve be used for buried service?
Yes, fully welded ball valves are commonly selected for buried service, but the valve must be supplied with suitable stem extension, coating, corrosion protection, drain or vent arrangement and operation method according to the project requirement.
5. What information is needed for quotation?
For quotation, provide valve size, pressure, temperature, medium, end connection, installation type, stem extension length, body material, seat material, coating requirement, operation method, testing requirement and any API 6D, EN 488, fire-safe, NACE or DBB requirement.