Parveen Industries Pvt. Ltd. Designs Junk Subs Capture and Trap Junks. The Junk Subs Capture and Trap Junks fall in the category of Down Hole Flow Control Systems. Parveen Industries Pvt. Ltd. Is an ISO 9001:2000 certified company. The Junk Subs Capture and Trap Junks are designed to be used in drill collar string just above the rock bit or milling tool. The tool consists of a steel mandrel with an oversized sleeve or `skirt` attached over the mandrel. The `skirt` will trap the large cutting and junk which are too heavy to be circulated out of the hole. The `skirt` is manufactured with bleed holes to allow the mud to drain once it is brought out of the hole. It is recommended that two Junk Subs be run in tandem to decrease the possibility of junk bypassing a single Junk Sub. The Junk Subs do not have welding on its body. The Junk Subs are used directly above the Mill or drilling bit for easy removal of cuttings. In hard milling jobs, two or three junk subs are run one after the other. This increases capacity to remove cuttings and provides additional stabilization to mill.