There is provided a valve (2, 102, 302, 402) which comprises a housing (4, 04, 204, 304, 404) in which a movable valve element (6, 106, 206, 306, 406) having first and second valve members (14a, 14b 114a, 114b 214a, 214b 314a, 314b 414a, 414b) is disposed.A plurality of ports (A-E) are disposed in the housing, and first and second seal portions (8a, 8b 10a, 10b 108a, 108b 110a, 110b 208a, 208b 210a, 210b 308a, 308b 310a, 310b 408a, 408b 410a, 410b) are connected to the housing. The first and second seal portions each have a sealed configuration in which first and second pairs of ports are sealed from one another with the first and second valve members respectively. At least one of the first seal portion and the first valve member is deformable such that, when only the first seal portion is in the sealed configuration with the first valve member, deformation allows the second seal portion to be brought into the sealed configuration with the second valve member, and/or at least one the second seal portion and the second valve member is deformable such that, when only the second seal portion is in the sealed configuration with the second valve member, deformation allows the first seal portion to be brought into the sealed configuration with the first valve member.La présente invention concerne une vanne (2, 102, 302, 402) qui comprend un logement (4, 04, 204, 304, 404) dans lequel un élément de vanne mobile (6, 106, 206, 306, 406) ayant des premier et second éléments de vanne (14a, 14b 114a, 114b 214a, 214b 314a, 314b 414a, 414b) est disposé. Une pluralité dorifices (A-E) sont disposés dans le logement, et des première et seconde parties détanchéité (8a, 8b 10a, 10b 108a, 108b 110a, 110b 208a, 208b 210a, 210b 308a, 308b 310a, 310b 408a, 408b 410a, 410b) sont raccordées au logement. Les première et seconde parties détanchéité ont chacune une configuration détanchéité dans laquelle les première et seconde paires dorifices sont étanches lune vis-à-vis de laut
