Diameter restriction of tubing after application of fitting

[edleit]

I am curious to know if there is any data available on the resultant diameters of tubing (specifically, ASTM A269 TY304) after Swagelok/Gyrolok type fittings have been installed to recommended torque values.

We have seen some constriction in tubing ID and would like to find out if this reduction is within "normal" limits. The application uses 1/4" x .035 wall tubing.

Ed Leitkowski
South Windsor, CT

 

[unclesyd]

Our piping design people at one time did a lot of work in this area when comparing Swagelok vs Tylok tubing fittings. As I recall there was no measurable effect of the swagging of the tubing until you got into the max flow regions of the tubing. Canvassing our pilot plants and the steam tracing bunch revealed that there was no cause for concern at our flow conditions. Again recalling from the wind farm the reduction is normally within the size limits of most tubing, with the exception of some precision bore.

Again if I'm not mistaken Swagelok has paper that discusses this in some detail.