663, 664, 666 & 668 (W) Single Actuator Welded Chamber Mounted Switch

Models 663W, 664W, 666W and 668W are single actuator controls.  Each control is available with a wide variety of switches.  These units are long welded chambers with nominal body diameters of 3” to 8”.  The long welded steel chamber totally encloses the solid graphite displacer (S.S. displacer optional).  Connections are 1” NPT (standard).  Other process connection sizes and configurations are available. These units are sized to meet your specific gravity and switching differential needs.  “W” chambers are also used for interface service and when a stainless steel displacer or special body length is required.

Pressure and temperature rating for these controls is 150 to 1000 psig at 500º F.  Special materials of construction available on request.

The standard specific gravity setting of the liquid is specified on Table A (reverse side).  If the specific gravity of the liquid increases, the switching differential will decrease.  If the specific gravity of the liquid decreases, the switching differential will increase. Consult the factory with the application if the specific gravity of the liquid varies more than 0.1 from the standard specific gravity setting.


  • Factory Calibrated to each applications Specific Gravity
  • Hydrostatically Tested at 1.5 times the maximum design pressure
  • Available in CS, 304SS, 316SS
  • UL & CSA Approved

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