A valve assembly for controlling fluid flow along a fluid line, comprising - an outer shell (12, 512) having a through bore, a distal end, and a proximal end; - an inner housing movably engaged within the outer shell (12, 512) and having a central boss having a through bore with a distal end opening and a connector portion (24, 26, 524) surrounding the central boss at a distal end portion of the inner housing and configured for connecting the valve assembly in a fluid line; - a sealing pin coupled to the outer shell (12, 512) and extending into the through bore of the central boss to define a passageway in the central boss around the sealing pin; the sealing pin having a distal tip which is configured for sealing engagement in the distal end opening of the central boss through bore to prevent fluid flow through the distal end opening in a first, closed position of the inner housing and which is spaced from the open distal end of the central boss in a second, open position to open a fluid path through the central boss around the sealing pin and out of the distal end opening; and - the inner housing being rotationally movable in a first direction relative to the outer shell (12, 512) and sealing pin between the first, closed position and the second, open position on connection of the connector portion (24, 26, 524) to a fluid line and in a second, opposite direction relative to the outer shell between the second, open position and the first, closed position to close the fluid path; characterized in that - the inner housing is biased towards the first, closed position on separation of the connector portion from the fluid line; and - the valve assembly comprises a torque limiter mechanism between the outer shell (12, 512) and inner housing comprising at least one first interengageable formation (514, 516) on the outer shell and at least one second interengageable formation (514, 516) on the inner housing, one of the interengageable formations (514, 516, 512) comprising at least one indent and the other interengageable formation (512, 514, 516) comprising at least one flexible member biased into engagement in said indent in the first, closed position of the inner housing, whereby rotational movement of said inner housing in said first direction is resisted by engagement of an end face of said indent with said flexible member until the biasing force of said flexible member is overcome. - an outer shell (12, 512) having a through bore, a distal end, and a proximal end; - an inner housing movably engaged within the outer shell (12, 512) and having a central boss having a through bore with a distal end opening and a connector portion (24, 26, 524) surrounding the central boss at a distal end portion of the inner housing and configured for connecting the valve assembly in a fluid line; - a sealing pin coupled to the outer shell (12, 512) and extending into the through bore of the central boss to define a passageway in the central boss around the sealing pin; the sealing pin having a distal tip which is configured for sealing engagement in the distal end opening of the central boss through bore to prevent fluid flow through the distal end opening in a first, closed position of the inner housing and which is spaced from the open distal end of the central boss in a second, open position to open a fluid path through the central boss around the sealing pin and out of the distal end opening; and - the inner housing being rotationally movable in a first direction relative to the outer shell (12, 512) and sealing pin between the first, closed position and the second, open position on connection of the connector portion (24, 26, 524) to a fluid line and in a second, opposite direction relative to the outer shell between the second, open position and the first, closed position to close the fluid path; characterized in that - the inner housing is biased towards the first, closed position on separation of the connector portion from the fluid line; and - the valve assembly comprises a torque limiter mechanism between the outer shell (12, 512) and inner housing comprising at least one first interengageable formation (514, 516) on the outer shell and at least one second interengageable formation (514, 516) on the inner housing, one of the interengageable formations (514, 516, 512) comprising at least one indent and the other interengageable formation (512, 514, 516) comprising at least one flexible member biased into engagement in said indent in the first, closed position of the inner housing, whereby rotational movement of said inner housing in said first direction is resisted by engagement of an end face of said indent with said flexible member until the biasing force of said flexible member is overcome.