... .,Ltd is one of the top level wellhead christmas tree manufacturers and suppliers,Website:http://www.zztopdownhole.com, with ... (hydraulic) safety valve Specification of the X-tree Working pressure (psi) 2M, 3M, 5M, 10M, 15M, 20K Material class AA ... PR2 Master bore (in) 2-1/16, 2-9/16, 3-1/16(3-1/8), 4-1/16 Pass-by bore (in ... ) 2-1/16, 2-9/16, 3-1/16(3-1/8), 4-1 ...