The Catcher for Mechanical Cutter ZTRV is used to retrieve parts of cut pipes with cutter in one session (max 16 tons).
The construction does not allow to move up after lowering the equipment and positioning the cutter with catcher into shank bore of cut pipes. That is why it is important to choose the cutting line accurately. In case of premature wedging of cutter to let the cutter “lock in place” and continue lowering process Catcher allows to make little upward movement (90 mm). After cutting process Catcher fixes the cut part of pipe and starts its retrieving with packaging arrangement. If for some reason the cut did not happen, spider should be released with lifting force 1-1,5 tons bigger than its weight-carrying ability.
If free retrieving of cutter with Catcher does not happen, the casing should be unloaded until free downward movement begins and then the packaging arrangement should be retrieved. After retrieving the cut part of pipe Catcher and cutter are removed towards the nozzle of cutter.
Under favorable completion of works detach and clean the cutter, lubricate thread and guide channels of slips. Make sure that slips move freely and are securely fixed in grooves. Put the tool into the box until next use.
If during operation the tool was emergency retrieved, disassemble parts of the Catcher and change shear bolts. To do so unscrew locking screw, take off sub, remove spring with washers, and then extract the pusher. From threaded hole of pusher unscrew heads of shear bolts, extract cut guards from the hole of conic hub. Put the pusher to proper grooves of conic hub, match the holes and screw new bolts against the stop. Assemble the tool in reverse order.