Allow tenders with distributing valve

Author: cesarBLG

Source/Orts.Simulation/Simulation/RollingStocks/SubSystems/Brakes/MSTS/AirSinglePipe.cs

@@ -286,7 +286,9 @@ public override void Initialize(bool handbrakeOn, float maxPressurePSI, float fu
             if (Car.Simulator.Settings.CorrectQuestionableBrakingParams && Car.CarLengthM <= 1)
             EmergResVolumeM3 = Math.Min (0.02f, EmergResVolumeM3);
 
-            if (Car.Simulator.Settings.CorrectQuestionableBrakingParams && (Car as MSTSWagon).BrakeValve == MSTSWagon.BrakeValveType.None)
+            // Install a plain triple valve if no brake valve defined
+            // Do not install it for tenders if not defined, to allow tenders with straight brake only
+            if (Car.Simulator.Settings.CorrectQuestionableBrakingParams && (Car as MSTSWagon).BrakeValve == MSTSWagon.BrakeValveType.None && (Car as MSTSWagon).WagonType != TrainCar.WagonTypes.Tender)
             {
                 (Car as MSTSWagon).BrakeValve = MSTSWagon.BrakeValveType.TripleValve;
                 Trace.TraceWarning("{0} does not define a brake valve, defaulting to a plain triple valve", (Car as MSTSWagon).WagFilePath);
@@ -352,7 +354,7 @@ public void UpdateTripleValveState(float elapsedClockSeconds)
                 else
                     TripleValveState = ValveState.Lap;
             }
-            else if (valveType == MSTSWagon.BrakeValveType.TripleValve || valveType == MSTSWagon.BrakeValveType.Distributor)
+            else if (valveType == MSTSWagon.BrakeValveType.TripleValve || valveType == MSTSWagon.BrakeValveType.DistributingValve)
             {
                 if (BrakeLine1PressurePSI < AuxResPressurePSI - 1 && EmergencyValveActuationRatePSIpS > 0 && (prevBrakePipePressurePSI - BrakeLine1PressurePSI) > Math.Max(elapsedClockSeconds, 0.0001f) * EmergencyValveActuationRatePSIpS)
                     TripleValveState = ValveState.Emergency;
@@ -442,7 +444,7 @@ public override void Update(float elapsedClockSeconds)
             }
 
             // triple valve set to release pressure in brake cylinder and EP valve set
-            if (TripleValveState == ValveState.Release)
+            if (TripleValveState == ValveState.Release && (Car as MSTSWagon).BrakeValve != MSTSWagon.BrakeValveType.None)
             {
                 if ((Car as MSTSWagon).EmergencyReservoirPresent)
 				{