(under subclass 179) Devices in which the packer or plug seals the space between the surrounding conduit and two longitudinally extending members which are positioned in side by side relationship (not one within the other).
(1) Note. These devices are usually packings for a pump tube and a gas vent pipe. Where more structure is involved than a mere packing such a device is classifiable in Class 417 as a pump venting means.
