... 2FZ2835,2FZ 2870, 2FZ3535, ZFZ3570 and 2FZ5414 ram blowout preventer: double ram blowout preventertype:2FZ1835, 2FZ1870,2FZ2835,2FZ 2870, 2FZ3535, ... material: 35CrMo OR 25CrNiMo3)working pressure: 2000PSI--15000PSI A blowout preventer is a large, specialized valve used to seal, ... control and monitor oil and gas wells. Blowout preventers were developed to cope with extreme erratic pressures ...