Landis & Gyr SQL33 Actuator

The Landis & Gyr SQL33 is a classic industrial valve actuator used primarily in heating, ventilation, and air conditioning (HVAC) systems to control the flow of fluids. Landis & Gyr is a legendary Swiss company founded in the late 19th century, known for its precision engineering in metering and building automation.

Throughout the late 20th century, the brand underwent significant ownership changes. In 1998, the building automation division of Landis & Gyr was acquired by Siemens, a German multinational conglomerate. Consequently, while the brand name 'Landis & Gyr' still appears on legacy equipment like the one in the image, the intellectual property and manufacturing legacy now reside within Siemens Smart Infrastructure. Most of these high-precision components were historically manufactured in Switzerland or Germany, regions renowned for industrial automation excellence.