Adjustable Plungers

Adjustable Plungers (or flow adapters) have two principal uses in low pressure columns. They are used when you do not want to fill the column completely with your media and you do not want any space at the top of the packing. They are also frequently used in ascending flow chromatography.

When doing size exclusion or other conventional chromatography you may need to avoid having any fluid above the packing in the column. With an adjustable plunger you can lower the top of the fluid path to the top of your media. This is not a critical feature when doing adsorption chromatography.

Sometimes it is desirable to do ascending flow chromatography. This can minimize bed compression and yield superior performance for larger columns. When doing ascending flow chromatography a bed support is needed at both the top and bottom of the column. If the column is completely filled with resin, an additional lower end plate (available as a replacement item) can be put on the top of the column. If the column is not completely filled you would need to use an adjustable plunger at the top of the column. Even if the column is completely filled a plunger is frequently used since it tends to be more convenient.

If extreme adjustment of the column length is required, 2 plungers can be used on a single column, one on the top and a second on the bottom. This doubles the available adjustment length.

Because the adjustable plungers are a wetted parts, they are available in 2 different materials for different solvent conditions. The Aqueous plungers have polypropylene endplates and Nylon bed supports and are suitable for use with most aqueous solutions, including most acids bases and salts. The only wetted material in the organic series plungers is PTFE making them suitable for use with any chromatographic solvent.

Replacement grids, mesh, and O-rings are available for all of these plungers.

Adjustable Plunger Ordering Information
Column IDAdjustment LengthPart NumberParts
AqueousOrganicAqueousOrganic
0.6 cm10 cm124101125100herehere
0.9 cm10 cm124100125101herehere
1.5 cm10 cm124108125109herehere
2.5 cm16 cm124122125123herehere
5 cm 32 cm124136125139herehere
7.5 cm32 cm124142125141herehere
10 cm 32 cm124146125147herehere
15 cm 32 cm124152125149herehere

Exploded views of these plungers that show the individual parts and the construction are available with the replacement parts lists. Select the appropriate Parts link above to see the correct drawing.

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