National offers a full line of standard single level float switches. If you don’t see exactly what you need, a custom version can be configured to meet your specific requirements.
Single level switches are a simple solution for liquid level switching or indication. They are typically used for high- and low-level conditions. Conveniently mounts at the top or bottom of a tank or vessel. The floats can be reversed in the field to change the condition of the switch from normally open to normally closed and vice-versa.
An economical and versatile choice for the OEM or end user!
- Stainless Steel, Brass and Buna, PVC, and Polypropylene construction
- Available with SPST or SPDT reed switches
- 10va & 50va mini reeds/ 15va & 100va full size reeds
- 1/8” or 1/4” NPT mounting threads
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| Specifications* | SLS-15SSP | SLS-15BBP | SLS-110VVP | ILS-100BP |
| Stem Material | 316 S.S. | BRASS | PVC | BRASS |
| Float Material | 316 S.S. | BUNA-N | PVC | BUNA-N |
| Operating Temp. | -40° to 300°F | 150°F | 150°F | 150°F |
| Pressure Rating | 750 psi max | 150 psi max | 15 psi max | 150 psi max |
| Switches Available* | SPST, 15/100 VA | SPST, 15/100 VA | SPST, 15/100 VA | SPST, 15/100 VA |
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*Models shown are typical configurations of single level switches. Other configurations are available with SPDT switches-consult factory for specials.
| Switch Series: | Reed Rating: | Stem Material: | Float Material: | Thread Type: |
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| TLS-10SSP | TLS-10BBP | TLS-10PPP | TLS-10PPS | TLS-10NPS |
| 316 SS | BRASS | POLYPROPYLENE | POLYPRO | NYLON |
| 316 SS | BUNA-N | POLYPROPYLENE | POLYPRO | POLYPRO |
| 300°F max | 150°F | 230°F max | 230°F max | 230°F max |
| 150 psi max | 150 psi max | 150 psi max | 150 psi max | 150 psi max |
| SPST, 10VA | SPST, 10VA | SPST, 10VA | SPST, 10VA | SPST, 10VA |
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NOTE: Switch actuation points are approximately half the distance between the stem end and the mounting depending on the specific gravity of the liquid.
A Look Inside Our Model SLS-100BB
Simplicity…
A magnetic float is moved by the liquid level and actuates a hermetically sealed magnetic reedswitch which is located inside the stem of the unit. The switch closure is a direct reading of the actual liquid level without any conversions or calculations needed.
Reliability…
Reedswitch technology is a time proven method of reliable switching for a wide range of industrial, automotive and marine applications. This technology, supported by the quality construction of NATIONAL’S products, provides years of trouble free liquid level sensing.
Accuracy…
Repetitive accuracy is an inherent characteristic of NATIONAL’S products. Once a critical level is defined and a switch is mounted to sense that level, the magnetic float will close the switch consistently at the same level to within 1/16″.
Custom is Standard at National
Chemical processing, petrochemical, food and beverage, water and waste water treatment, heavy equipment, and energy… wherever liquids of any kind are stored, processed, transported, pumped, mixed, etc., there are numerous applications for level switches and controls. NATIONAL has supplied products for these and other industries since 1978 earning a reputation as a manufacturer with the FLEXIBILITY and EXPERTISE to conceptualize, design and build quality sensors to meet customer needs in a timely, cost effective manner. As a result our “standard” products are built from off the shelf components and offer versatility in configuration meeting a ride range of application requirements. PLEASE CALL our sales engineering department to discuss your application in the event you don’t easily find a sensor to meet your needs.