A system for ensuring against improper interconnection of fluid lines, comprising: a kit including devices with channels (10A, 10B) that convey fluid and coupling devices (1A, 1B, 30A, 30B, 31A, 31B) for interconnecting the channels; each of the coupling devices (1A, 30A, 31A) having at least one connector (15A, 16A, 35A, 37A) configured to connect with at least one connector (15B, 16B, 35B, 37B) on another of said coupling devices (1B, 30B, 31B) when the at least one connector of said each of the coupling devices is oriented in a predefined physical relationship with the at least one connector of said another of said coupling devices, in order to fluidly connect the at least one connector of said each of the coupling devices to the at least one connector of the another of said coupling devices; at least some of the coupling devices having at least one interfering element (32A, 34A) arranged thereon that, when oriented in the predefined physical relationship, comes into interfering engagement with the at least one interfering element (32C, 34C) of first others of the coupling devices to prevent said at least some from being connected to the first others of the coupling devices but permit said at least some to be connected to second others of the coupling devices; wherein each of at least some of the coupling devices comprises a furcated fluid channel (10A, 10B, 846) and the at least one connector of each of at least some of the coupling devices is a multiple of connectors (15A, 15B, 16A, 16B, 35A, 35B, 37A, 37B), each said multiple of connectors connects to said furcated fluid channel (10A, 10B, 846) that converges to a single fluid channel in the each of the at least some of the coupling devices; and wherein said multiple of connectors of each of the said at least some coupling devices (30A, 30B, 30C) of the said coupling devices comprises at least one female connector and at least one male connector. a kit including devices with channels (10A, 10B) that convey fluid and coupling devices (1A, 1B, 30A, 30B, 31A, 31B) for interconnecting the channels; each of the coupling devices (1A, 30A, 31A) having at least one connector (15A, 16A, 35A, 37A) configured to connect with at least one connector (15B, 16B, 35B, 37B) on another of said coupling devices (1B, 30B, 31B) when the at least one connector of said each of the coupling devices is oriented in a predefined physical relationship with the at least one connector of said another of said coupling devices, in order to fluidly connect the at least one connector of said each of the coupling devices to the at least one connector of the another of said coupling devices; at least some of the coupling devices having at least one interfering element (32A, 34A) arranged thereon that, when oriented in the predefined physical relationship, comes into interfering engagement with the at least one interfering element (32C, 34C) of first others of the coupling devices to prevent said at least some from being connected to the first others of the coupling devices but permit said at least some to be connected to second others of the coupling devices; wherein each of at least some of the coupling devices comprises a furcated fluid channel (10A, 10B, 846) and the at least one connector of each of at least some of the coupling devices is a multiple of connectors (15A, 15B, 16A, 16B, 35A, 35B, 37A, 37B), each said multiple of connectors connects to said furcated fluid channel (10A, 10B, 846) that converges to a single fluid channel in the each of the at least some of the coupling devices; and wherein said multiple of connectors of each of the said at least some coupling devices (30A, 30B, 30C) of the said coupling devices comprises at least one female connector and at least one male connector.