Wye fitting attachment

An assembly for connecting a wye fitting to a valve of a fluid system, the assembly including:

• the wye fitting, wherein the wye fitting defines a main fluid flow path along an axis A between a first end and a second end;
• the valve, wherein the valve includes a port;
• and
• a clamshell fastener;
• wherein the second end is configured to be connected to the port and is provided with a plurality of first engagement features arranged circumferentially around the end of the wye fitting and the port is provided with a corresponding plurality of second engagement features arranged circumferentially around the port that engage with the first engagement features such that the second end does not rotate relative to the port when the port rotates,
• wherein the clamshell is secured around the second end of the wye fitting and the valve over an interface between the first and second engagement features,
• wherein the first engagement features comprise protrusions extending axially from the end of the wye fitting and the second engagement features comprise corresponding recesses formed around the end of the valve arranged to receive the protrusions, or the second engagement features comprise protrusions extending axially from the end of the valve and the first engagement features comprise corresponding recesses formed around the end of the wye fitting arranged to receive the protrusions.