32 of fuel through the fuel line inlet 22 a through flow 34 of fuel within the inner cylindrical structure 20 and an outflow 36 of fuel at the fuel line outlet 24 continuing with reference to fig2 it will be seen that the outer cylindrical structure 40 essentially u201c overwraps u201d a portion of the inner cylindrical structure 20 the outer cylindrical structure 40 including a sidewall 42 the sidewall having a first end 46 and a second end 48 at the first end 46 of the outer cylindrical structure 40 is a first sealed end cap 56 similarly at the second end 48 of the outer cylindrical structure 40 there is a second sealed end cap 58 the first and second sealed end caps 56 58 respectively each include an aperture not shown through which a portion of the inner cylindrical structure 20 passes the sidewall 42 and the sealed end caps 56 58 of the outer cylindrical structure 40 comprise and form an inner chamber 44 of the outer cylindrical structure 40 in application it will be seen that an inlet port 52 is sealingly provided at the first end 46 of the outer cylindrical structure 40 as is an outlet port 54 that is located at the second end 48 of the outer cylindrical structure 40 see also fig1 the inlet port 52 of the outer cylindrical structure 40 is sealingly attached to a coolant inlet line 62 similarly the outlet port 54 of the outer cylindrical structure 40 is sealingly connected to a coolant outlet line 64 also in application is the fact that the coolant inlet line 62 and the inlet port 52 of the outer cylindrical structure 40 provide for the inlet flow 72 of coolant into the outer cylindrical.