First check whether your laboratory screw joint (inner diameter) fits your tubing (outer diameter). If it is still difficult to put the tubing inside the inner parts of the laboratory screw joint, a trick can be helpful. Just either sharpen the tubing with a simple sharpener or cut it diagonally. You should now be able to easily put the tubing through the inner parts.
With BOLA Tube Fittings and Reducing Unions, transition from imperial to metric tubing or connections between both can easily be made. For example: A pipe socket of an analytical device with an outer diameter of 1/4" shall be connected to a PTFE tubing with an outer diameter of 8 mm.
Needed components: Reducing union 6 mm to 8 mm (Cat.No. D 526-10) and a set of tapered V-rings Ø 1/4" (6.35 mm; Cat.No. D 502-03). By exchanging the 6 mm V-rings with the 1/4" V-rings, the pipe socket can be connected to the 1/4" reducing union and the 8 mm PTFE tubing on the other side.
At high temperatures, under vacuum or with thin wall thickness we recommend
to support the tubing in the laboratory screw joint. This can for example be made by using a short piece of glass or metal tube. Consequently, the tubing cannot turn off to the inside and become leaky. This trick allows also to connect elastic, gummy tubing to GL threads by means of BOLA Laboratory Screw joints.
In general, cleaned fluoroplastic tubing should only be reused if the transported product is known and rated with “+” in the chemical resistance chart.
It is not recommended to reuse the tubing with unknown products and mixtures of chemicals. For all water-soluble substances (e.g. salts, acids, bases etc) you can use water as cleaning agent.
Volatile solvents such as alcohols, esters, ketones, low-boiling hydrocarbons, chlorinated hydrocarbons are given off reversibly by storing under aeration (only if they have not been absorbed by the interior surface of the tubing).
If you are using substances which can only be eliminated by organic solvents or if you are using toxic and dangerous products, the tubing should be disposed appropriately after use. A visual inspection or, in case of unclarity an inspection according to EN 12115, has to be made before reusing cleaned tubing.
URL of this page: http://www.bola.de/en/technical-information/tubing/tubing-assembly-and-cleaning.html