GL Threads

GL threads are externally threaded glass fittings.
They come in a range of sizes, some simply tooled on borosilicate tubing, some molded on bottles.
The inside diameters of the glass show the maximum passthrough.
There are closed caps, open caps, septum seals, and sealing rings for all sizes.
The sealing rings accommodate tubes or electrodes at nominal diameter ± ~ 1 mm.

Dimensions in millimeters.

Size  ID tube (bottle) OD 

Available sealing IDs

GL14 8.5 12 6
GL18 10.5 16 6, 8, 10
GL25 (tube) 18 22 8, 10, 12
GL25 (25 ml bottle) 14.3 (36) 8, 10, 12
GL32 (tube) 24 28 10, 12, 14, 16, 18
GL32 (50 ml bottle) 17 (46) 10, 12, 14, 16
GL45 (tube) 35 40 26, 32
GL45 (100 ml bottle) 30 (55) 26, 32
GLS80 (500 ml bottle) 65 (102)  

Some of the ways of connecting with GL threads are shown here for GL14 options; the larger sizes have similar possibilities.

There are teflon inserts for GL14 that hold and seal 1.6 mm (1/16"), 3 mm, 3.2 mm (1/8"), and 6 mm tubes or electrodes.

GL Septa Options (/images/uploads/3176.jpg)
There are a number of off-the-shelf options for sealing rings, septa, inserts, hose barbs, etc. This hardware will seal to a variety of materials. More example can be found here.

Various Sealing Options (/images/uploads/2584.jpeg)949402

GL14 fittings (/images/uploads/2795.jpg)Sealing Ring Assembly (/images/uploads/3054.jpg)

Jacketed Bundled Reactor detail (/images/uploads/2995.jpg)
951632
Extractor porting (/images/uploads/2873.jpg)
950264

GL14 thread with flexible tubing through sealing ring

Sealed and closed up tight