... valves, spools and fittings for an oil well, and to design to direct and control formation Tubing Head Spool and Xmas:Working ... oil, gas, drilling fluid, gas contained H2S, CO2Working temperature: -46degree to 121degree (L U)Material class: AA, BB, CC, DD, EE ... , FFSpecification level: 1-4Performance requirement: 1-2To complete with air or hydraulic safety valve at option Tubing Head Spool and X-mas