The Spirax Sarco M10Si is an ISO three-piece steam isolation ball valve available in full-bore and reduced-bore configurations, with threaded, butt-weld, socket-weld, and flanged connections. The valve body is available in zinc-plated carbon steel or 316L stainless steel. With a maximum working pressure of 17.5 bar g on saturated steam, it is suitable for on/off isolation, in-line maintenance, and automated remote operation in industrial steam and other fluid pipelines.
Spirax Sarco three-piece steam isolation ball valve M10Si ISO three-quarter product photo
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M10Si ISO / M10Si ISO Automation Three-Piece Steam Isolation Ball Valve | Spirax Sarco
Three-piece steam isolation ball valve available with a lockable manual handle or as a handle-less Automation build for pneumatic or electric actuators; shared body, pressure rating, and materials.
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Specifications
- Valve type
- 3-piece ball valve (isolation valve)
- Bore type
- Full bore (FB) and reduced bore (RB)
- Connection size range
- 1/4" to 2-1/2" (RB), 1/4" to 2" (FB)
- End connections
- BSP/BSPT/API/NPT threaded, butt weld (BW), socket weld (SW), flanged
- Flange standards
- EN 1092 PN40, ASME Class 150, ASME Class 300
- Maximum allowable pressure (PMA)
- 100 bar g@60°C
- Maximum allowable temperature (TMA)
- 260°C@0 bar g
- Minimum allowable temperature
- -29°C
- Maximum operating pressure for saturated steam (PMO)
- 17.5 bar g
- Maximum cold hydrostatic test pressure
- 150 bar g
- Maximum differential pressure
- Limited by PMO
- Leakage rate
- ISO 5208 Rate A / EN 12266-1 Rate A
- Flow characteristic
- Modified linear
- Body material
- Galvanized carbon steel ASTM A105 / stainless steel ASTM A182 F 316L
- Ball material
- Stainless steel AISI 316
- Seat seal material
- Carbon/graphite-reinforced PTFE (PDR 0.8)
- Kv range
- Reduced bore: 2.5-168, full bore: 2.5-205
- Operating torque range
- 3.25 to 75 Nm (maximum differential pressure 40 bar)
- Anti-static design
- Complies with ISO 7121 and BS 5351
- Certifications
- Pressure Equipment Directive 97/23/EC (CE), EN 10204 3.1
Application scenarios
Isolation in industrial steam lines
Used for on/off operation and isolation in industrial steam mains, branch lines, or upstream or downstream of steam-consuming equipment. This 3-piece isolation ball valve is specified for steam service, with a maximum operating pressure for saturated steam of 17.5 bar g.
In-line maintenance of threaded or welded industrial piping
Used in industrial fluid lines with threaded or welded connections that require maintenance. Product documentation states that valves with these connection types can be serviced without removing the valve body from the pipeline.
Remote switching and automation in industrial fluid lines
Used for remote on/off operation and automated control of industrial fluid lines. Product documentation states that the ISO mounting design allows valve automation without removing or disassembling the valve body and without compromising seal integrity. Manual or remote operation is supported.
Isolation in vacuum and industrial process lines
Used for sectional isolation in vacuum service and other industrial fluid process lines. Product documentation specifies suitability for steam and other industrial fluids from vacuum conditions to elevated temperatures and pressures, and identifies the valve as an isolation valve.
Selection points
ISO mounting supports future automation
The integral ISO mounting design supports valve automation, enabling manual or remote operation without removing or disassembling the valve body while maintaining seal integrity.
Carbon/graphite-reinforced PTFE seat for steam isolation
This series uses a carbon/graphite-reinforced PTFE (PDR 0.8) seat and is designed as a steam isolation ball valve.
3-piece ball valve construction
This product has a 3-piece ball valve construction and is designed for isolation service.
Full-bore and reduced-bore configurations
This series is available in full-bore and reduced-bore versions. The size range is 1/4 inch to 2 inches for full bore and 1/4 inch to 2-1/2 inches for reduced bore, with maximum Kv values of 205 and 168, respectively.
Multiple pipeline connection options
This series is available with BSP/BSPT/API/NPT threaded, butt-weld, socket-weld, and flanged connections. Flange standards include EN 1092 PN40, ASME Class 150, and ASME Class 300.
Installation & maintenance notes
Remove internal seals before welding
For butt-weld or socket-weld connections, remove the internal seals before welding to prevent welding heat from damaging the PDR 0.8 seat and associated sealing components.
FAQ
How does the M10Si ISO ball valve work, and where is it used?
The M10Si ISO is a 3-piece isolation ball valve for steam and other industrial fluids. It can be used from vacuum conditions to elevated temperatures and pressures as an isolation valve, not a control valve.
What are the key selection considerations when comparing the M10Si ISO with a standard ball valve?
Consider whether full bore or reduced bore is required, the material selection (galvanized carbon steel, stainless steel, or all stainless steel), the connection type (threaded, welded, flanged, etc.), whether a lockable handle is needed, and whether the certificates and temperature/pressure limits suit the application. Confirm the specific configuration against the actual model and application conditions.
How can an ISO ball valve be automated without compromising seal integrity?
The valve body is designed to remain assembled during installation, allowing the valve to be automated while maintaining seal integrity. Safe integration for both manual and remote operation is supported.
How are sealing and leakage performance ensured for this valve series?
The leakage rate complies with ISO 5208 Rate A / EN 12266-1 Rate A, and the valve has an anti-static design that complies with the relevant standards. Confirm the required leakage rate and operating environment during selection.
How should port and connection size markings be interpreted during selection?
FB means full bore, and RB means reduced bore. The size range covers 1/4" to 2" with threaded, welded, or flanged connections. Flange dimensions comply with standards including ASME and EN 1092 PN40. Check the model against the required size and connection type.