The standard manual radiator valves are used for the simple isolation and regulation of the flow rate in a central heating system. They are supplied in pairs an isolation valve and a lockshield valve. The lockshield valves are installed on the return branch and are used for the hydraulic balancing of the circuit. Valves are available in straight or angle pattern with male threads, female threads or Irish size compression connections. The angle pattern valve is also available with drain off connection.