One-Piece Flanged Ball Valve
One-Piece Flanged · DN15–DN150 · PN16/25 · WCB / SS316
Reguvale's one-piece flanged ball valve uses a single cast body that eliminates the split-body bolt line, giving the highest integrity for isolation duty in water, oil and mild chemical service.
Flanged ends per ISO 7005-2 make installation quick and the floating ball with PTFE seats delivers bubble-tight shutoff. Bodies in WCB or SS316 cover most plant utilities.
Key Features
Bubble-Tight Shutoff
Soft PTFE seats give zero-leakage shutoff for gas, water and chemical service.
Low Torque
Floating and trunnion designs keep operating torque low for lever or compact actuators.
Anti-Blowout Stem
Stem shoulder and live-loaded packing prevent ejection under line pressure.
Fire-Safe Design
Metal-to-metal backup seat holds line pressure after a fire (design principle; no API 607 certificate held).
Actuator Ready
ISO 5211 flange accepts pneumatic or electric actuators and gearboxes.
Full / Reduced Bore
Full-bore models give unobstructed Cv; reduced-bore saves weight and cost.
Technical Specifications
| Parameter | Specification |
|---|---|
| Body Material | WCB Carbon Steel / SS304 / SS316 / CF8M |
| Ball / Trim | SS304 / SS316 / 17-4PH |
| Seat Material | PTFE / RPTFE / PEEK / Metal |
| Size Range | DN15 – DN600 (1/2" – 24") |
| Pressure Rating | PN16 (ANSI 150 / 300) |
| End Connection | Flanged / Threaded / Welded / Wafer / Tri-clamp |
| Operation | Lever / Gear / Pneumatic / Electric Actuator |
| Bore | Full Bore / Reduced Bore |
| Fire Safe | Fire-safe design with metal backup seat (design principle; no API 607 certificate held) |
| Leakage Class | Bubble-tight, ANSI ISO 5208 Rate A (soft seat) |
| Standards | API 608 / ISO 17292 / GB/T 12237 |
| Certification | ISO 9001:2015, MTC available |
How to Specify a One-Piece Flanged Ball Valve
The one-piece flanged ball valve is the compact, economical end of the range. Its limitation is maintenance access, and that is the only thing worth deciding.
One-piece means no body joint to leak
With no split in the body there is one less leak path, and the valve is more compact than a two- or three-piece design of the same bore.
The trade-off is serviceability
A one-piece body cannot be opened to replace the ball and seats in the field. Where the valve is cheap and accessible, replacement is the maintenance strategy. Where it is buried or in a hazardous area, choose a design that can be serviced.
Flanged ends suit larger bores and higher classes
Flanged connections carry higher pressure classes and larger sizes more reliably than threaded ends, and they are the normal choice above DN50.
Seat material according to the medium
PTFE or RPTFE for general service, PEEK for higher temperature, metal where abrasion or temperature rules out a soft seat.
Automation is straightforward
The ISO 5211 mounting pad accepts a pneumatic or electric actuator, so a manual valve can be automated later without changing the valve.
Installation & Maintenance
Align the flanges before bolting up
A one-piece body cannot be adjusted to compensate for misalignment, so the pipe has to meet the valve squarely.
Tighten evenly in a cross pattern
Uneven bolt load distorts a one-piece body and loads the seat.
Leave actuator and handle clearance
Check the swing of the handle or the actuator envelope against neighbouring pipework before final positioning.
Decide the replacement strategy up front
If the valve cannot be isolated and removed easily, specify a serviceable design now rather than discovering it at the first failure.
Common Specification Mistakes
Specifying a one-piece body where field service is needed
The only maintenance option is replacement.
Pulling misaligned flanges together
A rigid one-piece body does not accommodate it.
Choosing it for a buried or confined installation
Replacement cost then exceeds the original saving.
Frequently Asked Questions
What is the difference between floating and trunnion ball valves?
Floating ball valves seat the ball against the downstream seat by line pressure (DN15–DN150). Trunnion-mounted balls are held by top and bottom shafts for larger sizes (DN200+) and higher pressures.
Which seat material should I choose?
PTFE / RPTFE for most chemicals and clean fluids up to +200°C. PEEK for higher temperature. Metal seat for slurry, abrasive or high-temperature service.
Can ball valves be used for throttling?
Ball valves are best for on/off. For modulating duty use our V-port control ball valves or control valves, which keep a stable characteristic curve.
Applications & Use Cases
Oil & Gas
Pipeline isolation, tank farm and loading arms with fire-safe soft seats.
Water & Utilities
Municipal water, HVAC and irrigation with flanged or wafer ends.
Chemical
Corrosive media handled in SS316 or PTFE-seated bodies.
Food & Pharma
Tri-clamp and polished SS316 ball valves for hygienic lines.
