The 8125 is a low-dispersion analog of Rheodyne?’s 7125 valve. It features reduced diameter flow passages, a new port geometry for easier loop attachment, and a built-in position sensing switch.

      Flow passages in the 8125 are only 0.25mm in diameter, resulting in a significant reduction in dispersion. The lower dispersion makes the 8125 valve suitable for use with conventional analytical columns (2 to 6mm ID) as well as with microbore (1mm and 2mm ID) columns where minimum extracolumn volume is critical. The 8125 valve has unique “dual size” ports for tubing connections. This allows either 1/16" OD or 0.02" OD tubing to be used. Connections to 1/16" column end fittings are facilitated with a connecting tube supplied with the valve. The smaller flow passages also result in more resistance to flow. This makes it harder to load large sample volumes. The maximum recommended sample volume for the 8125 valve is 500µL. All sample loops are externally plumbed.