NEPTs and Pressing Sleeves

NEPTs are the best, by far. However, they are not always the same OD. I made a PVC sleeve that fit very well. Later I noticed that the fit was bad. I discovered that the tubes were not all the same. The larger OD on some of the tubes, made a larger gap in my sleeve. This caused CATO problems.

Good and not so good fit.

For several reasons I think having a double walled sleeve is helpful. I made the inner sleeve from schedule 20 PVC, which is thinner. Being thinner, it is easier to cut and fit to the tube. If the inner sleeve fits well, the outer sleeve is not as critical. So, you can make different inner sleeves to better fit the tubes and have the outer sleeve for the main support. It seems that the two sleeves lock together somewhat, reducing the stress on the hose clamps.

Double wall sleeve