An embodiment of a balance bar (230) is disclosed. The balance bar (230) comprises a first side portion (231) having a hollow interior for receiving a flow tube (220), a central portion (233) having a hollow interior for receiving a flow tube (220), and a first side flexible portion (234) comprising at least one flexible coupler (250), the first side flexible portion (234) coupling the first side portion (231) with the central portion (233), wherein the first side portion (231) and the central portion (233) are both more rigid than the first side flexible portion (234).