The Spirax Sarco M31V ISO is a full-bore flanged ball valve designed solely for on/off pipeline isolation. Available in DN50-DN200 sizes, it features EN 1092 PN16 flanged connections and an ISO 5211 actuator mounting interface, with a maximum saturated steam pressure of 10 bar g. It is suitable for saturated steam mains, branch lines, and pipeline isolation points requiring automated control. It is not intended for continuous flow regulation.
M31V ISO full-bore flanged ball valve, 3/4-turn product image | Spirax Sarco
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M31V ISO Full-bore Flanged Ball Valve | Spirax Sarco
Full-bore flanged ball valve for on/off isolation in steam and industrial fluid pipelines, suitable for automated actuator operation.
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Specifications
- Valve type
- Full-bore ball valve, for isolation service only
- Nominal bore
- DN50, DN65, DN80, DN100, DN150, DN200
- Connection type
- EN 1092 PN16 flanges
- Mounting face standard
- DIN 3202 F1 and F4/F5
- Actuator mounting standard
- ISO 5211
- Flow characteristic
- Modified linear
- Leakage class
- EN 12266-1 Class A / ISO 5208 Class A
- Antistatic standard
- Complies with ISO 7121
- Maximum allowable pressure
- 16 bar g @ 50°C
- Maximum allowable temperature
- 230°C @ 0 bar g
- Operating temperature range
- -29°C to 230°C @ 0 bar g
- Maximum saturated steam pressure
- 10 bar g
- Cold hydrostatic test pressure
- 24 bar g
- Valve body material
- Galvanized carbon steel ASTM A216 WCB (M31V2 ISO) or stainless steel ASTM A351 CF8M (M31V3 ISO)
- Ball material
- Stainless steel AISI 316
- Seat material
- PTFE
- Stem seal material
- PTFE
- Flow coefficient Kv
- DN50: 300; DN65: 430; DN80: 770; DN100: 1030; DN150: 2390; DN200: 4530
- Operating torque
- DN50: 40 Nm; DN65: 50 Nm; DN80: 70 Nm; DN100: 200 Nm; DN150: 600 Nm; DN200: 750 Nm
Application scenarios
Isolation of saturated steam mains and branches
Used for on-off isolation in industrial steam mains or branch lines. This valve is for isolation service only, with a maximum saturated steam pressure of 10 bar g and full-bore sizes from DN50 to DN200.
Automated pipeline isolation
Used at pipeline isolation points requiring remote or program-controlled operation. The valve features an actuator mounting interface compliant with ISO 5211 and is intended for on-off isolation only, not continuous flow control.
Selection points
Full-bore isolation design
The M31V ISO features a full-bore design and is intended for isolation service.
ISO 5211 actuator mounting interface
The actuator mounting interface complies with ISO 5211 and can be used as a basis for actuator matching and automation configuration.
Soft-seated shutoff and antistatic compliance
The product uses PTFE seats, achieves EN 12266-1 Class A and ISO 5208 Class A leakage ratings, and complies with ISO 7121 for antistatic performance.
Saturated steam pressure limit
The maximum saturated steam pressure is 10 bar g. Valve selection for steam service must remain within this pressure limit.
Two valve body material options
The M31V2 ISO uses a galvanized carbon steel ASTM A216 WCB valve body, while the M31V3 ISO uses a stainless steel ASTM A351 CF8M valve body. Both models use PTFE seats and an ISO actuator mounting interface.
PN16 flanges and mounting face standards
The product uses EN 1092 PN16 flanged connections, with mounting faces complying with DIN 3202 F1 and F4/F5.
Installation & maintenance notes
For on-off isolation only
The M31V ISO full-bore ball valve is for isolation service only. During commissioning and operation, it should be fully open or fully closed and must not be used as a control valve for prolonged throttling at an intermediate opening.
FAQ
How does the M31V ISO full-bore ball valve work?
The M31V ISO full-bore ball valve is used for isolation service. It opens or closes the flow path by rotating the ball and provides a full-bore passage to reduce pressure drop. In principle, it is not intended for flow control.
How should the valve size and flange connection be selected?
Available sizes are DN50, DN65, DN80, DN100, DN150, and DN200. The flanges comply with EN 1092 PN16, and the mounting face dimensions comply with DIN 3202 F1/F4/F5.
What material and design features improve reliability?
The valve body and components use different material combinations. The seats are PTFE, and the valve body is available in galvanized carbon steel or stainless steel. Components such as the stem and ball use stainless steel, while the valve's antistatic performance complies with the relevant standards to ensure sealing performance at high temperatures and in high-temperature steam service.
What standards and certificate information are available for this valve?
The product complies with the European Pressure Equipment Directive 97/23/EC and can be supplied with the CE marking upon request. An EN 10204 3.1 certificate is available.
What should be considered during installation and maintenance?
Refer to the guide supplied with the product for installation and maintenance. Valve size and model must be selected according to the application conditions. Where necessary, confirm that the ISO actuator mounting interface and flange connection are compatible with the site operating conditions.