Sample loops are accurately sized for each valve type. However, with small volume loops the tolerance on the ID of the tubing (± 0.001") can have a significant effect on the volume. Therefore loop volume and loop appearance may differ from batch to batch.
Loops include PEEK nuts and ferrules. Loops smaller than 500 µl are made from 1/16" tubing; loops 500 µl or bigger are made from 1/8" OD tubing with polymeric unions and 1/16" ends.