Abstract: A valve (8) is fitted into a channel arrangement having a first inner channel (1) which extends longitudinally carrying a first fluid. An outer channel (4) encloses channel (1) and is intended for the passage of a second fluid at a lower temperature. The valve assembly has at least two valves to control flow through the outer channel (4). The outer channel (4) is made up of two. U-shaped channel portions (12,13) each extending outwardly with regard to the inner channel (1). Each of the channels (12,13) has at least one of said first valves (9) to control fluid flow and the inner channel (1) may have another valve (10) to control it's flow.