diff --git a/applications/test/TestTools/TestTools.H b/applications/test/TestTools/TestTools.H
index 82dfe5e38b..e8470d8b27 100644
--- a/applications/test/TestTools/TestTools.H
+++ b/applications/test/TestTools/TestTools.H
@@ -28,15 +28,14 @@ Description
 
 \*---------------------------------------------------------------------------*/
 
-using namespace Foam;
-
-#include "floatScalar.H"
-#include "doubleScalar.H"
+#include "scalar.H"
 #include "complex.H"
 #include "Matrix.H"
 #include "Random.H"
 #include <chrono>
 
+using namespace Foam;
+
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 // Total number of unit tests
diff --git a/applications/test/matrices/DiagonalMatrix/Test-DiagonalMatrix.C b/applications/test/matrices/DiagonalMatrix/Test-DiagonalMatrix.C
index 3d8ae06979..e0b962be22 100644
--- a/applications/test/matrices/DiagonalMatrix/Test-DiagonalMatrix.C
+++ b/applications/test/matrices/DiagonalMatrix/Test-DiagonalMatrix.C
@@ -38,8 +38,7 @@ Description
 
 #include "DiagonalMatrix.H"
 #include "RectangularMatrix.H"
-#include "floatScalar.H"
-#include "doubleScalar.H"
+#include "scalar.H"
 #include "complex.H"
 #include "TestTools.H"
 
diff --git a/applications/test/matrices/RectangularMatrix/Test-RectangularMatrix.C b/applications/test/matrices/RectangularMatrix/Test-RectangularMatrix.C
index fbcf4c6343..86690ba60f 100644
--- a/applications/test/matrices/RectangularMatrix/Test-RectangularMatrix.C
+++ b/applications/test/matrices/RectangularMatrix/Test-RectangularMatrix.C
@@ -44,8 +44,7 @@ Note
 
 #include "RectangularMatrix.H"
 #include "SquareMatrix.H"
-#include "floatScalar.H"
-#include "doubleScalar.H"
+#include "scalar.H"
 #include "complex.H"
 #include "IOmanip.H"
 #include "TestTools.H"
diff --git a/applications/test/matrices/SquareMatrix/Test-SquareMatrix.C b/applications/test/matrices/SquareMatrix/Test-SquareMatrix.C
index d114dd3963..3a45461899 100644
--- a/applications/test/matrices/SquareMatrix/Test-SquareMatrix.C
+++ b/applications/test/matrices/SquareMatrix/Test-SquareMatrix.C
@@ -45,8 +45,7 @@ Note
 #include "scalarMatrices.H"
 #include "RectangularMatrix.H"
 #include "SquareMatrix.H"
-#include "floatScalar.H"
-#include "doubleScalar.H"
+#include "scalar.H"
 #include "complex.H"
 #include "IOmanip.H"
 #include "TestTools.H"
diff --git a/applications/test/matrices/SymmetricSquareMatrix/Test-SymmetricSquareMatrix.C b/applications/test/matrices/SymmetricSquareMatrix/Test-SymmetricSquareMatrix.C
index c3d47e59b0..ab404872c1 100644
--- a/applications/test/matrices/SymmetricSquareMatrix/Test-SymmetricSquareMatrix.C
+++ b/applications/test/matrices/SymmetricSquareMatrix/Test-SymmetricSquareMatrix.C
@@ -46,8 +46,7 @@ Note
 #include "RectangularMatrix.H"
 #include "SquareMatrix.H"
 #include "SymmetricSquareMatrix.H"
-#include "floatScalar.H"
-#include "doubleScalar.H"
+#include "scalar.H"
 #include "complex.H"
 #include "IOmanip.H"
 #include "Random.H"
diff --git a/applications/utilities/postProcessing/dataConversion/foamToVTK/foamToVTK.C b/applications/utilities/postProcessing/dataConversion/foamToVTK/foamToVTK.C
index cf683535d0..22f3bdd5c4 100644
--- a/applications/utilities/postProcessing/dataConversion/foamToVTK/foamToVTK.C
+++ b/applications/utilities/postProcessing/dataConversion/foamToVTK/foamToVTK.C
@@ -232,13 +232,13 @@ vtk::outputOptions getOutputOptions(const argList& args)
 
         if (!args.found("ascii"))
         {
-            if (sizeof(floatScalar) != 4 || sizeof(label) != 4)
+            if (sizeof(float) != 4 || sizeof(label) != 4)
             {
                 opts.ascii(true);
 
                 WarningInFunction
                     << "Using ASCII rather than legacy binary VTK format since "
-                    << "floatScalar and/or label are not 4 bytes in size."
+                    << "float and/or label are not 4 bytes in size."
                     << nl << endl;
             }
             else
diff --git a/src/OpenFOAM/db/IOstreams/IOstreams/Istream.H b/src/OpenFOAM/db/IOstreams/IOstreams/Istream.H
index d14ab64fb3..998fa0e90a 100644
--- a/src/OpenFOAM/db/IOstreams/IOstreams/Istream.H
+++ b/src/OpenFOAM/db/IOstreams/IOstreams/Istream.H
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2017-2021 OpenCFD Ltd.
+    Copyright (C) 2017-2022 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -156,11 +156,11 @@ public:
             //- Read a label
             virtual Istream& read(label&) = 0;
 
-            //- Read a floatScalar
-            virtual Istream& read(floatScalar&) = 0;
+            //- Read a float
+            virtual Istream& read(float&) = 0;
 
-            //- Read a doubleScalar
-            virtual Istream& read(doubleScalar&) = 0;
+            //- Read a double
+            virtual Istream& read(double&) = 0;
 
             //- Read binary block
             virtual Istream& read(char*, std::streamsize) = 0;
diff --git a/src/OpenFOAM/db/IOstreams/IOstreams/Ostream.H b/src/OpenFOAM/db/IOstreams/IOstreams/Ostream.H
index 7f76df67b3..c89b8b4c8e 100644
--- a/src/OpenFOAM/db/IOstreams/IOstreams/Ostream.H
+++ b/src/OpenFOAM/db/IOstreams/IOstreams/Ostream.H
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2016-2021 OpenCFD Ltd.
+    Copyright (C) 2016-2022 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -147,11 +147,11 @@ public:
             //- Write int64_t
             virtual Ostream& write(const int64_t val) = 0;
 
-            //- Write floatScalar
-            virtual Ostream& write(const floatScalar val) = 0;
+            //- Write float
+            virtual Ostream& write(const float val) = 0;
 
-            //- Write doubleScalar
-            virtual Ostream& write(const doubleScalar val) = 0;
+            //- Write double
+            virtual Ostream& write(const double val) = 0;
 
             //- Write binary block.
             virtual Ostream& write(const char* data, std::streamsize count) = 0;
diff --git a/src/OpenFOAM/db/IOstreams/Pstreams/UIPstream.H b/src/OpenFOAM/db/IOstreams/Pstreams/UIPstream.H
index 0e522fa263..e51b0ac9f6 100644
--- a/src/OpenFOAM/db/IOstreams/Pstreams/UIPstream.H
+++ b/src/OpenFOAM/db/IOstreams/Pstreams/UIPstream.H
@@ -156,11 +156,11 @@ public:
             //- Read a label
             Istream& read(label& val);
 
-            //- Read a floatScalar
-            Istream& read(floatScalar& val);
+            //- Read a float
+            Istream& read(float& val);
 
-            //- Read a doubleScalar
-            Istream& read(doubleScalar& val);
+            //- Read a double
+            Istream& read(double& val);
 
             //- Read binary block with 8-byte alignment.
             Istream& read(char* data, std::streamsize count);
diff --git a/src/OpenFOAM/db/IOstreams/Pstreams/UIPstreamBase.C b/src/OpenFOAM/db/IOstreams/Pstreams/UIPstreamBase.C
index 9e61fdcad6..0dd6469332 100644
--- a/src/OpenFOAM/db/IOstreams/Pstreams/UIPstreamBase.C
+++ b/src/OpenFOAM/db/IOstreams/Pstreams/UIPstreamBase.C
@@ -359,7 +359,7 @@ Foam::Istream& Foam::UIPstreamBase::read(token& t)
         // Float
         case token::tokenType::FLOAT :
         {
-            floatScalar val;
+            float val;
             if (read(val))
             {
                 t = val;
@@ -374,7 +374,7 @@ Foam::Istream& Foam::UIPstreamBase::read(token& t)
         // Double
         case token::tokenType::DOUBLE :
         {
-            doubleScalar val;
+            double val;
             if (read(val))
             {
                 t = val;
@@ -432,14 +432,14 @@ Foam::Istream& Foam::UIPstreamBase::read(label& val)
 }
 
 
-Foam::Istream& Foam::UIPstreamBase::read(floatScalar& val)
+Foam::Istream& Foam::UIPstreamBase::read(float& val)
 {
     readFromBuffer(val);
     return *this;
 }
 
 
-Foam::Istream& Foam::UIPstreamBase::read(doubleScalar& val)
+Foam::Istream& Foam::UIPstreamBase::read(double& val)
 {
     readFromBuffer(val);
     return *this;
diff --git a/src/OpenFOAM/db/IOstreams/Pstreams/UOPstream.H b/src/OpenFOAM/db/IOstreams/Pstreams/UOPstream.H
index b5c9248d2d..a316ee450c 100644
--- a/src/OpenFOAM/db/IOstreams/Pstreams/UOPstream.H
+++ b/src/OpenFOAM/db/IOstreams/Pstreams/UOPstream.H
@@ -173,11 +173,11 @@ public:
             //- Write int64_t as a label
             virtual Ostream& write(const int64_t val);
 
-            //- Write floatScalar
-            virtual Ostream& write(const floatScalar val);
+            //- Write float
+            virtual Ostream& write(const float val);
 
-            //- Write doubleScalar
-            virtual Ostream& write(const doubleScalar val);
+            //- Write double
+            virtual Ostream& write(const double val);
 
             //- Write binary block with 8-byte alignment.
             virtual Ostream& write(const char* data, std::streamsize count);
diff --git a/src/OpenFOAM/db/IOstreams/Pstreams/UOPstreamBase.C b/src/OpenFOAM/db/IOstreams/Pstreams/UOPstreamBase.C
index 7dee1199c9..12daa2f140 100644
--- a/src/OpenFOAM/db/IOstreams/Pstreams/UOPstreamBase.C
+++ b/src/OpenFOAM/db/IOstreams/Pstreams/UOPstreamBase.C
@@ -304,7 +304,7 @@ Foam::Ostream& Foam::UOPstreamBase::write(const int64_t val)
 }
 
 
-Foam::Ostream& Foam::UOPstreamBase::write(const floatScalar val)
+Foam::Ostream& Foam::UOPstreamBase::write(const float val)
 {
     putChar(token::tokenType::FLOAT);
     writeToBuffer(val);
@@ -312,7 +312,7 @@ Foam::Ostream& Foam::UOPstreamBase::write(const floatScalar val)
 }
 
 
-Foam::Ostream& Foam::UOPstreamBase::write(const doubleScalar val)
+Foam::Ostream& Foam::UOPstreamBase::write(const double val)
 {
     putChar(token::tokenType::DOUBLE);
     writeToBuffer(val);
diff --git a/src/OpenFOAM/db/IOstreams/Sstreams/ISstream.C b/src/OpenFOAM/db/IOstreams/Sstreams/ISstream.C
index ad422dc7c8..7222b81f1b 100644
--- a/src/OpenFOAM/db/IOstreams/Sstreams/ISstream.C
+++ b/src/OpenFOAM/db/IOstreams/Sstreams/ISstream.C
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2017-2021 OpenCFD Ltd.
+    Copyright (C) 2017-2022 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -1001,7 +1001,7 @@ Foam::Istream& Foam::ISstream::read(label& val)
 }
 
 
-Foam::Istream& Foam::ISstream::read(floatScalar& val)
+Foam::Istream& Foam::ISstream::read(float& val)
 {
     is_ >> val;
     setState(is_.rdstate());
@@ -1009,7 +1009,7 @@ Foam::Istream& Foam::ISstream::read(floatScalar& val)
 }
 
 
-Foam::Istream& Foam::ISstream::read(doubleScalar& val)
+Foam::Istream& Foam::ISstream::read(double& val)
 {
     is_ >> val;
     setState(is_.rdstate());
diff --git a/src/OpenFOAM/db/IOstreams/Sstreams/ISstream.H b/src/OpenFOAM/db/IOstreams/Sstreams/ISstream.H
index 67894c8645..026b672571 100644
--- a/src/OpenFOAM/db/IOstreams/Sstreams/ISstream.H
+++ b/src/OpenFOAM/db/IOstreams/Sstreams/ISstream.H
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2012 OpenFOAM Foundation
-    Copyright (C) 2017-2021 OpenCFD Ltd.
+    Copyright (C) 2017-2022 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -36,8 +36,8 @@ SourceFiles
 
 \*---------------------------------------------------------------------------*/
 
-#ifndef ISstream_H
-#define ISstream_H
+#ifndef Foam_ISstream_H
+#define Foam_ISstream_H
 
 #include "Istream.H"
 #include "fileName.H"
@@ -183,11 +183,11 @@ public:
             //- Read a label
             virtual Istream& read(label& val);
 
-            //- Read a floatScalar
-            virtual Istream& read(floatScalar& val);
+            //- Read a float
+            virtual Istream& read(float& val);
 
-            //- Read a doubleScalar
-            virtual Istream& read(doubleScalar& val);
+            //- Read a double
+            virtual Istream& read(double& val);
 
             //- Read binary block
             virtual Istream& read(char* buf, std::streamsize count);
diff --git a/src/OpenFOAM/db/IOstreams/Sstreams/OSstream.C b/src/OpenFOAM/db/IOstreams/Sstreams/OSstream.C
index 78644b4e89..744274e667 100644
--- a/src/OpenFOAM/db/IOstreams/Sstreams/OSstream.C
+++ b/src/OpenFOAM/db/IOstreams/Sstreams/OSstream.C
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2017-2021 OpenCFD Ltd.
+    Copyright (C) 2017-2022 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -196,7 +196,7 @@ Foam::Ostream& Foam::OSstream::write(const int64_t val)
 }
 
 
-Foam::Ostream& Foam::OSstream::write(const floatScalar val)
+Foam::Ostream& Foam::OSstream::write(const float val)
 {
     os_ << val;
     setState(os_.rdstate());
@@ -204,7 +204,7 @@ Foam::Ostream& Foam::OSstream::write(const floatScalar val)
 }
 
 
-Foam::Ostream& Foam::OSstream::write(const doubleScalar val)
+Foam::Ostream& Foam::OSstream::write(const double val)
 {
     os_ << val;
     setState(os_.rdstate());
diff --git a/src/OpenFOAM/db/IOstreams/Sstreams/OSstream.H b/src/OpenFOAM/db/IOstreams/Sstreams/OSstream.H
index 44e1de4afa..ba9a2d607f 100644
--- a/src/OpenFOAM/db/IOstreams/Sstreams/OSstream.H
+++ b/src/OpenFOAM/db/IOstreams/Sstreams/OSstream.H
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2014 OpenFOAM Foundation
-    Copyright (C) 2017-2021 OpenCFD Ltd.
+    Copyright (C) 2017-2022 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -36,8 +36,8 @@ SourceFiles
 
 \*---------------------------------------------------------------------------*/
 
-#ifndef OSstream_H
-#define OSstream_H
+#ifndef Foam_OSstream_H
+#define Foam_OSstream_H
 
 #include "Ostream.H"
 #include "fileName.H"
@@ -155,11 +155,11 @@ public:
             //- Write int64_t
             virtual Ostream& write(const int64_t val);
 
-            //- Write floatScalar
-            virtual Ostream& write(const floatScalar val);
+            //- Write float
+            virtual Ostream& write(const float val);
 
-            //- Write doubleScalar
-            virtual Ostream& write(const doubleScalar val);
+            //- Write double
+            virtual Ostream& write(const double val);
 
             //- Write binary block
             virtual Ostream& write(const char* data, std::streamsize count);
diff --git a/src/OpenFOAM/db/IOstreams/Sstreams/prefixOSstream.C b/src/OpenFOAM/db/IOstreams/Sstreams/prefixOSstream.C
index ccb16b613f..f2c3567bce 100644
--- a/src/OpenFOAM/db/IOstreams/Sstreams/prefixOSstream.C
+++ b/src/OpenFOAM/db/IOstreams/Sstreams/prefixOSstream.C
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2014 OpenFOAM Foundation
-    Copyright (C) 2020 OpenCFD Ltd.
+    Copyright (C) 2020-2022 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -140,14 +140,14 @@ Foam::Ostream& Foam::prefixOSstream::write(const int64_t val)
 }
 
 
-Foam::Ostream& Foam::prefixOSstream::write(const floatScalar val)
+Foam::Ostream& Foam::prefixOSstream::write(const float val)
 {
     checkWritePrefix();
     return OSstream::write(val);
 }
 
 
-Foam::Ostream& Foam::prefixOSstream::write(const doubleScalar val)
+Foam::Ostream& Foam::prefixOSstream::write(const double val)
 {
     checkWritePrefix();
     return OSstream::write(val);
diff --git a/src/OpenFOAM/db/IOstreams/Sstreams/prefixOSstream.H b/src/OpenFOAM/db/IOstreams/Sstreams/prefixOSstream.H
index f84e1dbd91..fa6967c381 100644
--- a/src/OpenFOAM/db/IOstreams/Sstreams/prefixOSstream.H
+++ b/src/OpenFOAM/db/IOstreams/Sstreams/prefixOSstream.H
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2014 OpenFOAM Foundation
-    Copyright (C) 2020-2021 OpenCFD Ltd.
+    Copyright (C) 2020-2022 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -38,8 +38,8 @@ SourceFiles
 
 \*---------------------------------------------------------------------------*/
 
-#ifndef prefixOSstream_H
-#define prefixOSstream_H
+#ifndef Foam_prefixOSstream_H
+#define Foam_prefixOSstream_H
 
 #include "OSstream.H"
 
@@ -143,11 +143,11 @@ public:
             //- Write int64_t
             virtual Ostream& write(const int64_t val);
 
-            //- Write floatScalar
-            virtual Ostream& write(const floatScalar val);
+            //- Write float
+            virtual Ostream& write(const float val);
 
-            //- Write doubleScalar
-            virtual Ostream& write(const doubleScalar val);
+            //- Write double
+            virtual Ostream& write(const double val);
 
             //- Write binary block
             virtual Ostream& write(const char* buf, std::streamsize count);
diff --git a/src/OpenFOAM/db/IOstreams/Tstreams/ITstream.C b/src/OpenFOAM/db/IOstreams/Tstreams/ITstream.C
index 124fdb6396..fb3a491a3e 100644
--- a/src/OpenFOAM/db/IOstreams/Tstreams/ITstream.C
+++ b/src/OpenFOAM/db/IOstreams/Tstreams/ITstream.C
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2015 OpenFOAM Foundation
-    Copyright (C) 2017-2021 OpenCFD Ltd.
+    Copyright (C) 2017-2022 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -530,14 +530,14 @@ Foam::Istream& Foam::ITstream::read(label&)
 }
 
 
-Foam::Istream& Foam::ITstream::read(floatScalar&)
+Foam::Istream& Foam::ITstream::read(float&)
 {
     NotImplemented;
     return *this;
 }
 
 
-Foam::Istream& Foam::ITstream::read(doubleScalar&)
+Foam::Istream& Foam::ITstream::read(double&)
 {
     NotImplemented;
     return *this;
diff --git a/src/OpenFOAM/db/IOstreams/Tstreams/ITstream.H b/src/OpenFOAM/db/IOstreams/Tstreams/ITstream.H
index d2dbebfcec..c463bab8f2 100644
--- a/src/OpenFOAM/db/IOstreams/Tstreams/ITstream.H
+++ b/src/OpenFOAM/db/IOstreams/Tstreams/ITstream.H
@@ -304,11 +304,11 @@ public:
             //- Read a label
             virtual Istream& read(label&);
 
-            //- Read a floatScalar
-            virtual Istream& read(floatScalar&);
+            //- Read a float
+            virtual Istream& read(float&);
 
-            //- Read a doubleScalar
-            virtual Istream& read(doubleScalar&);
+            //- Read a double
+            virtual Istream& read(double&);
 
             //- Read binary block
             //  \note Not implemented
diff --git a/src/OpenFOAM/db/IOstreams/Tstreams/OTstream.C b/src/OpenFOAM/db/IOstreams/Tstreams/OTstream.C
index 7dc51413e5..c1134f44e1 100644
--- a/src/OpenFOAM/db/IOstreams/Tstreams/OTstream.C
+++ b/src/OpenFOAM/db/IOstreams/Tstreams/OTstream.C
@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2019-2021 OpenCFD Ltd.
+    Copyright (C) 2019-2022 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -125,7 +125,7 @@ Foam::Ostream& Foam::OTstream::write(const int64_t val)
 }
 
 
-Foam::Ostream& Foam::OTstream::write(const floatScalar val)
+Foam::Ostream& Foam::OTstream::write(const float val)
 {
     append(token(val)); // tokenType::FLOAT
 
@@ -133,7 +133,7 @@ Foam::Ostream& Foam::OTstream::write(const floatScalar val)
 }
 
 
-Foam::Ostream& Foam::OTstream::write(const doubleScalar val)
+Foam::Ostream& Foam::OTstream::write(const double val)
 {
     append(token(val)); // tokenType::DOUBLE
 
diff --git a/src/OpenFOAM/db/IOstreams/Tstreams/OTstream.H b/src/OpenFOAM/db/IOstreams/Tstreams/OTstream.H
index 2cdd55e2a4..3f7561c5fb 100644
--- a/src/OpenFOAM/db/IOstreams/Tstreams/OTstream.H
+++ b/src/OpenFOAM/db/IOstreams/Tstreams/OTstream.H
@@ -5,7 +5,7 @@
     \\  /    A nd           | www.openfoam.com
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
-    Copyright (C) 2019-2021 OpenCFD Ltd.
+    Copyright (C) 2019-2022 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -38,8 +38,8 @@ SourceFiles
 
 \*---------------------------------------------------------------------------*/
 
-#ifndef OTstream_H
-#define OTstream_H
+#ifndef Foam_OTstream_H
+#define Foam_OTstream_H
 
 #include "token.H"
 #include "Ostream.H"
@@ -146,11 +146,11 @@ public:
         //- Write int64_t as a label
         virtual Ostream& write(const int64_t val);
 
-        //- Write floatScalar
-        virtual Ostream& write(const floatScalar val);
+        //- Write float
+        virtual Ostream& write(const float val);
 
-        //- Write doubleScalar
-        virtual Ostream& write(const doubleScalar val);
+        //- Write double
+        virtual Ostream& write(const double val);
 
         //- Write binary block with 8-byte alignment.
         virtual Ostream& write(const char* data, std::streamsize count);
diff --git a/src/OpenFOAM/db/IOstreams/dummy/dummyISstream.H b/src/OpenFOAM/db/IOstreams/dummy/dummyISstream.H
index 01ebb38d68..0af74bc015 100644
--- a/src/OpenFOAM/db/IOstreams/dummy/dummyISstream.H
+++ b/src/OpenFOAM/db/IOstreams/dummy/dummyISstream.H
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2017 OpenFOAM Foundation
-    Copyright (C) 2019-2020 OpenCFD Ltd.
+    Copyright (C) 2019-2022 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -40,8 +40,8 @@ SourceFiles
 
 \*---------------------------------------------------------------------------*/
 
-#ifndef dummyISstream_H
-#define dummyISstream_H
+#ifndef Foam_dummyISstream_H
+#define Foam_dummyISstream_H
 
 #include "StringStream.H"
 
@@ -108,15 +108,15 @@ public:
                 return *this;
             }
 
-            //- Read a floatScalar
-            virtual Istream& read(floatScalar&)
+            //- Read a float
+            virtual Istream& read(float&)
             {
                 NotImplemented;
                 return *this;
             }
 
-            //- Read a doubleScalar
-            virtual Istream& read(doubleScalar&)
+            //- Read a double
+            virtual Istream& read(double&)
             {
                 NotImplemented;
                 return *this;
diff --git a/src/OpenFOAM/db/IOstreams/token/token.H b/src/OpenFOAM/db/IOstreams/token/token.H
index aea0a49629..70a22c1b97 100644
--- a/src/OpenFOAM/db/IOstreams/token/token.H
+++ b/src/OpenFOAM/db/IOstreams/token/token.H
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2017-2021 OpenCFD Ltd.
+    Copyright (C) 2017-2022 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -307,8 +307,8 @@ private:
         int flagVal;   // bitmask - stored as int, not enum
         punctuationToken punctuationVal;
         label labelVal;
-        floatScalar floatVal;
-        doubleScalar doubleVal;
+        float floatVal;
+        double doubleVal;
 
         // Pointers
         word* wordPtr;
@@ -365,10 +365,10 @@ public:
         inline explicit token(const label val, label lineNum=0) noexcept;
 
         //- Construct float token
-        inline explicit token(const floatScalar val, label lineNum=0) noexcept;
+        inline explicit token(const float val, label lineNum=0) noexcept;
 
         //- Construct double token
-        inline explicit token(const doubleScalar val, label lineNum=0) noexcept;
+        inline explicit token(const double val, label lineNum=0) noexcept;
 
         //- Copy construct word token
         inline explicit token(const word& w, label lineNum=0);
@@ -531,11 +531,11 @@ public:
 
         //- Return float value.
         //  Report FatalIOError and return \b 0 if token is not FLOAT
-        inline floatScalar floatToken() const;
+        inline float floatToken() const;
 
         //- Return double value.
         //  Report FatalIOError and return \b 0 if token is not DOUBLE
-        inline doubleScalar doubleToken() const;
+        inline double doubleToken() const;
 
         //- Return float or double value.
         //  Report FatalIOError and return \b 0 if token is not a
@@ -607,10 +607,10 @@ public:
         inline void operator=(const label val);
 
         //- Copy assign from float
-        inline void operator=(const floatScalar val);
+        inline void operator=(const float val);
 
         //- Copy assign from double
-        inline void operator=(const doubleScalar val);
+        inline void operator=(const double val);
 
         //- Copy assign from word content
         inline void operator=(const word& w);
@@ -636,8 +636,8 @@ public:
         inline bool operator==(const token& tok) const;
         inline bool operator==(const punctuationToken p) const noexcept;
         inline bool operator==(const label val) const noexcept;
-        inline bool operator==(const floatScalar val) const noexcept;
-        inline bool operator==(const doubleScalar val) const noexcept;
+        inline bool operator==(const float val) const noexcept;
+        inline bool operator==(const double val) const noexcept;
         inline bool operator==(const std::string& s) const;
 
 
@@ -646,8 +646,8 @@ public:
         inline bool operator!=(const token& tok) const;
         inline bool operator!=(const punctuationToken p) const noexcept;
         inline bool operator!=(const label val) const noexcept;
-        inline bool operator!=(const floatScalar val) const noexcept;
-        inline bool operator!=(const doubleScalar val) const noexcept;
+        inline bool operator!=(const float val) const noexcept;
+        inline bool operator!=(const double val) const noexcept;
         inline bool operator!=(const std::string& s) const;
 
 
@@ -677,11 +677,11 @@ public:
 
         //- Return float value.
         //  \deprecated(2020-01) - floatToken()
-        floatScalar floatScalarToken() const { return floatToken(); }
+        float floatScalarToken() const { return floatToken(); }
 
         //- Return double value.
         //  \deprecated(2020-01) - doubleToken()
-        doubleScalar doubleScalarToken() const { return doubleToken(); }
+        double doubleScalarToken() const { return doubleToken(); }
 
         //- Deprecated(2017-11) transfer word pointer to the token
         //  \deprecated(2017-11) - use move assign from word
diff --git a/src/OpenFOAM/db/IOstreams/token/tokenI.H b/src/OpenFOAM/db/IOstreams/token/tokenI.H
index aa401e3496..e863649b73 100644
--- a/src/OpenFOAM/db/IOstreams/token/tokenI.H
+++ b/src/OpenFOAM/db/IOstreams/token/tokenI.H
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2017-2021 OpenCFD Ltd.
+    Copyright (C) 2017-2022 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -174,7 +174,7 @@ inline Foam::token::token(const label val, label lineNum) noexcept
 }
 
 
-inline Foam::token::token(const floatScalar val, label lineNum) noexcept
+inline Foam::token::token(const float val, label lineNum) noexcept
 :
     data_(),
     type_(tokenType::FLOAT),
@@ -184,7 +184,7 @@ inline Foam::token::token(const floatScalar val, label lineNum) noexcept
 }
 
 
-inline Foam::token::token(const doubleScalar val, label lineNum) noexcept
+inline Foam::token::token(const double val, label lineNum) noexcept
 :
     data_(),
     type_(tokenType::DOUBLE),
@@ -528,7 +528,7 @@ inline bool Foam::token::isFloat() const noexcept
 }
 
 
-inline Foam::floatScalar Foam::token::floatToken() const
+inline float Foam::token::floatToken() const
 {
     if (type_ == tokenType::FLOAT)
     {
@@ -546,7 +546,7 @@ inline bool Foam::token::isDouble() const noexcept
 }
 
 
-inline Foam::doubleScalar Foam::token::doubleToken() const
+inline double Foam::token::doubleToken() const
 {
     if (type_ == tokenType::DOUBLE)
     {
@@ -817,7 +817,7 @@ inline void Foam::token::operator=(const label val)
 }
 
 
-inline void Foam::token::operator=(const floatScalar val)
+inline void Foam::token::operator=(const float val)
 {
     reset();
     type_ = tokenType::FLOAT;
@@ -825,7 +825,7 @@ inline void Foam::token::operator=(const floatScalar val)
 }
 
 
-inline void Foam::token::operator=(const doubleScalar val)
+inline void Foam::token::operator=(const double val)
 {
     reset();
     type_ = tokenType::DOUBLE;
@@ -955,7 +955,7 @@ inline bool Foam::token::operator==(const label val) const noexcept
 }
 
 
-inline bool Foam::token::operator==(const floatScalar val) const noexcept
+inline bool Foam::token::operator==(const float val) const noexcept
 {
     return
     (
@@ -965,7 +965,7 @@ inline bool Foam::token::operator==(const floatScalar val) const noexcept
 }
 
 
-inline bool Foam::token::operator==(const doubleScalar val) const noexcept
+inline bool Foam::token::operator==(const double val) const noexcept
 {
     return
     (
@@ -993,13 +993,13 @@ inline bool Foam::token::operator!=(const label val) const noexcept
 }
 
 
-inline bool Foam::token::operator!=(const floatScalar val) const noexcept
+inline bool Foam::token::operator!=(const float val) const noexcept
 {
     return !operator==(val);
 }
 
 
-inline bool Foam::token::operator!=(const doubleScalar val) const noexcept
+inline bool Foam::token::operator!=(const double val) const noexcept
 {
     return !operator==(val);
 }
diff --git a/src/OpenFOAM/primitives/Scalar/doubleScalar/doubleScalar.H b/src/OpenFOAM/primitives/Scalar/doubleScalar/doubleScalar.H
index c75623c51c..5718d2d79d 100644
--- a/src/OpenFOAM/primitives/Scalar/doubleScalar/doubleScalar.H
+++ b/src/OpenFOAM/primitives/Scalar/doubleScalar/doubleScalar.H
@@ -35,8 +35,8 @@ SourceFiles
 
 \*---------------------------------------------------------------------------*/
 
-#ifndef doubleScalar_H
-#define doubleScalar_H
+#ifndef Foam_doubleScalar_H
+#define Foam_doubleScalar_H
 
 #include "scalarFwd.H"
 #include "doubleFloat.H"
diff --git a/src/OpenFOAM/primitives/Scalar/floatScalar/floatScalar.H b/src/OpenFOAM/primitives/Scalar/floatScalar/floatScalar.H
index a8546c87a8..cb5dd78912 100644
--- a/src/OpenFOAM/primitives/Scalar/floatScalar/floatScalar.H
+++ b/src/OpenFOAM/primitives/Scalar/floatScalar/floatScalar.H
@@ -35,8 +35,8 @@ SourceFiles
 
 \*---------------------------------------------------------------------------*/
 
-#ifndef floatScalar_H
-#define floatScalar_H
+#ifndef Foam_floatScalar_H
+#define Foam_floatScalar_H
 
 #include "scalarFwd.H"
 #include "doubleFloat.H"
diff --git a/src/OpenFOAM/primitives/Tensor/floats/doubleTensor.H b/src/OpenFOAM/primitives/Tensor/floats/doubleTensor.H
index 2002a5cb5b..b7eb317c7e 100644
--- a/src/OpenFOAM/primitives/Tensor/floats/doubleTensor.H
+++ b/src/OpenFOAM/primitives/Tensor/floats/doubleTensor.H
@@ -1,7 +1,7 @@
 // Compatibility include
 
-#ifndef doubleTensor_H
-#define doubleTensor_H
+#ifndef FoamCompat_doubleTensor_H
+#define FoamCompat_doubleTensor_H
 
 #include "tensor.H"
 
diff --git a/src/OpenFOAM/primitives/Tensor/floats/floatTensor.H b/src/OpenFOAM/primitives/Tensor/floats/floatTensor.H
index adb30f7975..26b67bcd5a 100644
--- a/src/OpenFOAM/primitives/Tensor/floats/floatTensor.H
+++ b/src/OpenFOAM/primitives/Tensor/floats/floatTensor.H
@@ -1,7 +1,7 @@
 // Compatibility include
 
-#ifndef floatTensor_H
-#define floatTensor_H
+#ifndef FoamCompat_floatTensor_H
+#define FoamCompat_floatTensor_H
 
 #include "tensor.H"
 
diff --git a/src/meshTools/triSurface/triSurfaceTools/triSurfaceTools.C b/src/meshTools/triSurface/triSurfaceTools/triSurfaceTools.C
index 920ef17b67..4d8660050d 100644
--- a/src/meshTools/triSurface/triSurfaceTools/triSurfaceTools.C
+++ b/src/meshTools/triSurface/triSurfaceTools/triSurfaceTools.C
@@ -2460,7 +2460,7 @@ Foam::triSurface Foam::triSurfaceTools::delaunay2D(const List<vector2D>& pts)
 {
     // Vertices in geompack notation. Note that could probably just use
     // pts.begin() if double precision.
-    List<doubleScalar> geompackVertices(2*pts.size());
+    List<double> geompackVertices(2*pts.size());
     label doubleI = 0;
     for (const vector2D& pt : pts)
     {