The folks at Winfield VFD (Maryland) recently had their Trident Automatic Air Primer upgraded to include a new control panel that uses a vacuum gauge graduated in "feet" of lift instead of the traditional inches of mercury. The new style gauge makes it much easier for the pump operator to assess lift conditions during drafting operations - as well as troubleshoot issues that can occur under vacuum conditions.

Winfield VFD was one of the first fire departments in the United States to have the automatic air primers installed and have retrofitted both of their engines with the devices.