The Spirax Sarco M40Si/M40Vi is a reduced-bore isolation ball valve with standard ISO mounting. It is intended solely for on/off pipeline isolation and must not be used as a control valve. Available with a carbon steel or stainless steel body, it features ASME Class 150/300 flanged connections and ISO 5208 leakage rate A. It is suitable for maintenance isolation, shutdown, and pipeline section isolation in industrial saturated steam transmission and distribution pipelines.
M40Si/M40Vi Reduced-Bore Isolation Ball Valve, Three-Quarter View | Spirax Sarco
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M40Si/M40Vi ISO Reduced-Bore Isolation Ball Valve | Spirax Sarco
Reduced-bore ball valve with standard ISO mounting for on/off isolation in saturated steam pipelines, available in two body materials.
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Specifications
- Valve function
- For isolation only; not suitable for use as a control valve
- Bore type
- Reduced bore
- Mounting type
- Standard ISO mounting
- Valve body design rating
- ASME Class 150 and ASME Class 300
- Flanged connection standard
- ASME Class 150 and ASME Class 300
- Nominal size
- DN25, DN32, DN40, DN50, DN65, DN80, DN100, DN150
- Maximum allowable pressure
- 51 bar g @ 38°C
- Maximum allowable temperature
- M40Si: 260°C @ 0 bar g; M40Vi: 230°C @ 0 bar g
- Minimum allowable temperature
- -29°C
- Maximum operating pressure for saturated steam
- M40Si: 17.5 bar g; M40Vi: 10.0 bar g
- Maximum cold hydraulic test pressure
- 76.5 bar g
- Leakage rating
- ISO 5208 Rate A / EN 12266-1 Rate A
- Antistatic option
- Compliant with ISO 7121 and BS 5351
- Valve body material
- Carbon steel ASTM A216 WCB or stainless steel ASTM A351 CF8M
- Seat material
- Carbon- and graphite-reinforced PTFE (PDR 0.8) or virgin PTFE
- Flow coefficient Kv
- DN25: 30; DN32: 40; DN40: 81; DN50: 103; DN65: 197; DN80: 248; DN100: 581; DN150: 735
- Operating torque
- DN25: 20 Nm; DN32: 25 Nm; DN40: 45 Nm; DN50: 50 Nm; DN65: 55 Nm; DN80: 110 Nm; DN100: 120 Nm; DN150: 140 Nm
- Pressure equipment compliance
- Compliant with European Pressure Equipment Directive 97/23/EC
- Material certification
- EN 10204 3.1 certification is available
Application scenarios
Industrial saturated steam pipeline isolation
Used for on-off isolation in industrial saturated steam transmission or distribution pipelines during equipment maintenance, shutdowns, or pipeline section isolation. This series is intended solely for use as an isolation valve. The maximum operating pressure for saturated steam is 17.5 bar g for the M40Si and 10.0 bar g for the M40Vi.
Selection points
Maximum saturated steam operating pressure by model
The M40Si and M40Vi have different maximum operating pressures for saturated steam: 17.5 bar g for the M40Si and 10.0 bar g for the M40Vi. Select the model according to the operating pressure of the steam system.
Installation & maintenance notes
For isolation service only
M40Si/M40Vi ISO reduced-bore ball valves are intended for isolation only. They must not be used as control valves for flow regulation or operated in a partially open position for extended periods.
FAQ
How do M40Si/M40Vi ISO ball valves operate?
M40Si/M40Vi valves are one-piece, reduced-bore ball valves featuring a combined body-and-seat construction. Rotation of the ball provides rapid isolation between the two ends. They are isolation valves and must not be used for flow control.
What are the key selection criteria for this ball valve?
Available models include M40Si2 ISO, M40Si3 ISO, M40Vi2 ISO, and M40Vi3 ISO. Sizes range from DN25-DN150, with flanged connections conforming to ASME 150/300. Seat and body material combinations vary, so selection should be based on the table and the actual process medium and temperature conditions. The specific configuration must be confirmed according to the selected model and application conditions.
Does this series comply with the relevant standards, and is certification available?
This product complies with European Pressure Equipment Directive 97/23/EC, and an EN 10204 3.1 certificate can be requested when ordering. If the € mark is required, specify this requirement when ordering.
Where can the medium temperature and pressure limits be found?
The valve body is designed to ASME 150/300 conditions. The PMA maximum pressure is 51 bar g @ 38°C, while TMA/MO and other temperature and differential pressure limits are within the ranges listed in the table. Actual operation must remain within the temperature and pressure limits provided on the page. Refer to the diagram for low-temperature and high-pressure regions.
How can an initial assessment be made for selection and maintenance?
Begin by comparing the size, seat material, body material, flange class, and whether an antistatic feature is required. For maintenance, refer to the installation and maintenance instructions supplied with the product for specific procedures and servicing requirements.