Arrow Back-Pressure Valve Type JF
Model “JF” Arrow Back-Pressure Valve is a sort of pipe inside blowout preventer. It adopts arrow valve structure. It's directly connected to drill stem, and can prevent high-pressure oil stream from blowing out from drilling tool.
Specifications
| Model | O.D. mm (in.) | I.D. mm (in.) | Length mm (in) | Connection |
| JF86 | 86 (3 3/8) | 34 (1 5/16) | 400 (15-3/4) | NC26 |
| JF105 | 105 (4 1/8) | 45 (1 3/4) | 400 (15-3/4) | NC31 |
| JF121 | 121 (4 3/4) | 57 (2 1/4) | 500 (19-11/16) | NC38 |
| JF152 | 152 (6) | 74 (2 15/16) | 500 (19-11/16) | NC46 |
| JF162 | 162 (6 3/8) | 83 (3 1/4) | 550 (21-5/8) | NC50 |
| JF165 | 165(6 1/2) | 71(2.8) | 914(36) | NC50 |
| JF184 | 184 (7 1/4) | 83 (3 1/4) | 550 (21-5/8) | 5 1/2FH |