Multiple Stage Cementing Collar This Tool is used to effectively cement upper sections of the casing string after displacing cement around the lower section. The Multiple Stage Cementing Collar provides a means of opening and closing port holes for cement displacement and positive containment of the cement after displacement. All internal parts are easily drilled, and are firmly held from rotating during drilling. The port closing sleeve is positively locked in position after cementing. When running the Collar it is advisable to place a Casing Centralizer above and below to run a Cementing Basket below the cementing ports.   After running the Collar to setting depth, the lower section is cemented in the conventional manner except the cement is displaced with the flexible cementing plug furnished with the collar. This is bumped against the shut-off Baffle which is also furnished. A slight pressure build-up of 300-400 P.S.I. will assure plug is seated in Baffle. The port holes in the Multiple Stage Cementing Collar are opened for doing the second stage by dropping the trip bomb and applying approximately 800-1000 P.S.I. pressure. The second stage is displaced with the closing plug which is also furnished with the Tool. When the closing plug bumps approximately 800-1000 P.S.I. pressure will close the port holes.   Multiple Stage Cementing Collar Size Part Number 4 1/2" 290-0044 5 1/2" 290-0054 7" 290-0070 7 5/8" 290-0075 8 5/8" 290-0085 9 5/8" 290-0095 10 3/4" 290-0106 11 3/4" 290-0116 12 3/4" 290-0126 13 3/8" 290-0133   (Downloadable PDF)