The DAN-EX Valve was introduced in 1979 by the Daniel Valve Company in Houston, Texas. The engineered valve was designed as an improved version of the General Twin Seal Valve. 

Approximately 8,000 (eight thousand) valves were produced by Daniel Valve between 1979 and 2000 and are installed worldwide. 

WesternValve purchased the DAN-EX Plug valve line in 2000 from Daniel Valve Company and currently manufactures the original design valve and aftermarket parts at is plant in California. 

The plant incorporates modern computerized manufacturing cells and utilizes the latest manufacturing practices to ensure the highest quality positive sealing valve in the industry.