Lug-style valves have threaded inserts at both sides of the valve body. This allows them to be installed into a system using two sets of bolts and no nuts. The valve is installed between two flanges using a separate set of bolts for each flange. This setup permits either side of the piping system to be disconnected without disturbing the other side.
A lug-style butterfly valve used in dead end service generally has a reduced pressure rating. For example, a lug-style butterfly valve mounted between two flanges has a 1,000 kPa (150 psi) pressure rating. The same valve mounted with one flange, in dead end service, has a 520 kPa (75 psi) rating. Lugged valves are extremely resistant to chemicals and solvents and can handle temperatures up to 200 °C, which makes it a versatile solution.