A self-closing coupling for use with comestible products, the coupling comprising: a first body having a first flow path extending therethrough; a second body having a second flow path extending therethrough; wherein the first body and the second body are configured for coupling together such that the first and second flow paths may form a continuous flow path extending through the coupling; wherein the first body and second body each comprise a valve member (120, 220) actuable between an open position, wherein product is able to pass through the continuous flow path, and a closed position, wherein the passage of product through the continuous path is prevented; and wherein the first body and second body each comprise a closure mechanism configured for actuating the respective valve member between the open and closed positions; wherein each closure mechanism includes a biasing member (150, 250) for biasing the respective valve member into the closed position; and wherein the coupling is configured for each valve member to self-close by switching from the open to closed position if the first and second bodies are undesirably decoupled from one another; wherein each biasing member is isolated from the flow of product passing through the continuous flow path; wherein each biasing member is operable in a chamber (130, 230) which is isolated from the continuous flow path, and wherein each biasing member is in operable communication with the respective valve member; each chamber is at least partially defined within a cylinder provided within the respective body (100, 200), wherein the interior of the cylinder is isolated from a flow of product from the continuous flow path; wherein each valve member comprises a piston-like body, a portion of which extends within the respective cylinder and is arranged for reciprocation within said cylinder, for moving the valve member between the open and closed positions; wherein the first body and second body each comprise a cylinder seal located between the cylinder and the piston-like body for sealing the cylinder against product ingress; wherein each valve member extends out of the respective first or second body with said valve member being te- in the closed position, and wherein the coupling is configured such that, with the first body and second body being brought together, the valve member on the first body cooperates with the valve member on the second body, so that a load is applied to cause the valve members to move from the closed position to the open position; wherein the coupling further comprises a valve sealing element to provide a seal between the cooperating valve members, and wherein the coupling is configured such that metal-to-metal contact between the cooperating valve members is prevented outboard of the valve sealing element. a first body having a first flow path extending therethrough; a second body having a second flow path extending therethrough; wherein the first body and the second body are configured for coupling together such that the first and second flow paths may form a continuous flow path extending through the coupling; wherein the first body and second body each comprise a valve member (120, 220) actuable between an open position, wherein product is able to pass through the continuous flow path, and a closed position, wherein the passage of product through the continuous path is prevented; and wherein the first body and second body each comprise a closure mechanism configured for actuating the respective valve member between the open and closed positions; wherein each closure mechanism includes a biasing member (150, 250) for biasing the respective valve member into the closed position; and wherein the coupling is configured for each valve member to self-close by switching from the open to closed position if the first and second bodies are undesirably decoupled from one another; wherein each biasing member is isolated from the flow of product passing through the continuous flow path; wherein each biasing member is operable in a chamber (130, 230) which is isolated from the continuous flow path, and wherein each biasing member is in operable communication with the respective valve member; each chamber is at least partially defined within a cylinder provided within the respective body (100, 200), wherein the interior of the cylinder is isolated from a flow of product from the continuous flow path; wherein each valve member comprises a piston-like body, a portion of which extends within the respective cylinder and is arranged for reciprocation within said cylinder, for moving the valve member between the open and closed positions; wherein the first body and second body each comprise a cylinder seal located between the cylinder and the piston-like body for sealing the cylinder against product ingress; wherein each valve member extends out of the respective first or second body with said valve member being te- in the closed position, and wherein the coupling is configured such that, with the first body and second body being brought together, the valve member on the first body cooperates with the valve member on the second body, so that a load is applied to cause the valve members to move from the closed position to the open position; wherein the coupling further comprises a valve sealing element to provide a seal between the cooperating valve members, and wherein the coupling is configured such that metal-to-metal contact between the cooperating valve members is prevented outboard of the valve sealing element.