Kobold SMN-5250U – SMN All-Metal Flow Switch, Stainless Steel, 1″ NPT, SPDT Contact
The Kobold SMN-5250U is an all-metal flow switch for liquids from Kobold’s SMN series, with a stainless steel body and wetted parts, a 1″ NPT female connection and an SPDT (changeover) reed contact. It combines a very low switch point with minimal pressure loss at high flow rates, and it is rated for pressures up to 350 bar (approx. 5,000 psi).
The changeover contact gives both a normally open and a normally closed output from one switch, which is useful when the same flow signal must, for example, stop a machine and trigger an alarm. Stainless steel gives better corrosion resistance than brass, so this version suits demineralised water, aggressive cooling water and contaminated media, as well as very high-pressure systems. The switch works on the float principle: a float with an integral magnet operates the reed contact at the switch point, and at higher flows an additional flow path opens, so the pressure drop stays low.
Key Technical Data – Kobold SMN-5250U
- Series: Kobold SMN all-metal flow switch
- Body and wetted parts: Stainless steel (1.4301); spring stainless steel; ceramic magnet
- Connection: 1″ NPT, female
- Switching range: ON 0.4–13 GPM; OFF 0.25–1 GPM (water)
- Media: Water or water-like, low-viscosity liquids
- Mounting: Vertical (upward flow) or horizontal
- Max. temperature: 100 °C (212 °F)
- Max. pressure: 350 bar (approx. 5,000 psi)
- Contact: Reed contact, SPDT (changeover)
- Electrical connection: DIN 43650 plug with cable gland
- Approval: cCSAus (SMN series)
Options and Related Models
- SMN-5250U: stainless steel, SPDT contact, cable gland (this item)
- SMN-5250: stainless steel, NO contact
- SMN-5250 CU: stainless steel, SPDT contact, 1/2″ NPT conduit fitting
- SMN-5150U: brass version with SPDT contact, max. 250 bar
- SMN-1250: stainless steel version with G1 female thread
Material, contact type and electrical connection must match the original installation. Our sales team can help you confirm the right version.
Typical Applications
- No-flow alarms with machine stop in high-pressure systems
- Demineralised or aggressive water circuits
- Effluent and contaminated media monitoring
- Replacement flow switches for installed SMN systems
Buy Kobold SMN-5250U from Atlantech Drives
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- 12-month warranty
- Senior commercial advice on flow switch versions and lead time
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