diff --git a/src/meshTools/searchableSurfaces/searchableDisk/searchableDisk.C b/src/meshTools/searchableSurfaces/searchableDisk/searchableDisk.C
index dec8298540..3fa74ec2fa 100644
--- a/src/meshTools/searchableSurfaces/searchableDisk/searchableDisk.C
+++ b/src/meshTools/searchableSurfaces/searchableDisk/searchableDisk.C
@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2014-2017 OpenFOAM Foundation
-    Copyright (C) 2018 OpenCFD Ltd.
+    Copyright (C) 2018-2020 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -72,9 +72,8 @@ Foam::pointIndexHit Foam::searchableDisk::findNearest
 
     v.normalise();
 
-
-    // Clip to radius.
-    info.setPoint(origin() + min(magV, radius_)*v);
+    // Clip to inner/outer radius
+    info.setPoint(origin() + radialLimits_.clip(magV)*v);
 
     if (magSqr(sample - info.rawPoint()) < nearestDistSqr)
     {
@@ -112,11 +111,10 @@ void Foam::searchableDisk::findLine
 
     v.normalise();
 
-
     // Set (hit or miss) to intersection of ray and plane of disk
     info.setPoint(origin() + magV*v);
 
-    if (magV <= radius_)
+    if (radialLimits_.contains(magV))
     {
         info.setHit();
         info.setIndex(0);
@@ -131,15 +129,15 @@ Foam::searchableDisk::searchableDisk
     const IOobject& io,
     const point& originPoint,
     const vector& normalVector,
-    const scalar radius
+    const scalar outerRadius,
+    const scalar innerRadius
 )
 :
     searchableSurface(io),
     plane(originPoint, normalVector),
-    radius_(radius)
+    radialLimits_(innerRadius, outerRadius)
 {
     // Rough approximation of bounding box
-    // vector span(radius_, radius_, radius_);
 
     // See searchableCylinder
     vector span
@@ -148,7 +146,7 @@ Foam::searchableDisk::searchableDisk
         sqrt(sqr(normal().x()) + sqr(normal().z())),
         sqrt(sqr(normal().x()) + sqr(normal().y()))
     );
-    span *= radius_;
+    span *= outerRadius;
 
     bounds().min() = origin() - span;
     bounds().max() = origin() + span;
@@ -166,7 +164,8 @@ Foam::searchableDisk::searchableDisk
         io,
         dict.get<point>("origin"),
         dict.get<vector>("normal"),
-        dict.get<scalar>("radius")
+        dict.get<scalar>("radius"),
+        dict.getOrDefault<scalar>("innerRadius", 0)
     )
 {}
 
@@ -177,8 +176,8 @@ const Foam::wordList& Foam::searchableDisk::regions() const
 {
     if (regions_.empty())
     {
-        regions_.setSize(1);
-        regions_[0] = "region0";
+        regions_.resize(1);
+        regions_.first() = "region0";
     }
     return regions_;
 }
@@ -190,11 +189,11 @@ void Foam::searchableDisk::boundingSpheres
     scalarField& radiusSqr
 ) const
 {
-    centres.setSize(1);
-    centres[0] = origin();
+    centres.resize(1);
+    radiusSqr.resize(1);
 
-    radiusSqr.setSize(1);
-    radiusSqr[0] = sqr(radius_);
+    centres[0] = origin();
+    radiusSqr[0] = sqr(radialLimits_.max());
 
     // Add a bit to make sure all points are tested inside
     radiusSqr += Foam::sqr(SMALL);
@@ -208,7 +207,7 @@ void Foam::searchableDisk::findNearest
     List<pointIndexHit>& info
 ) const
 {
-    info.setSize(samples.size());
+    info.resize(samples.size());
 
     forAll(samples, i)
     {
@@ -224,7 +223,7 @@ void Foam::searchableDisk::findLine
     List<pointIndexHit>& info
 ) const
 {
-    info.setSize(start.size());
+    info.resize(start.size());
 
     forAll(start, i)
     {
diff --git a/src/meshTools/searchableSurfaces/searchableDisk/searchableDisk.H b/src/meshTools/searchableSurfaces/searchableDisk/searchableDisk.H
index 23c66670e0..7dec54089f 100644
--- a/src/meshTools/searchableSurfaces/searchableDisk/searchableDisk.H
+++ b/src/meshTools/searchableSurfaces/searchableDisk/searchableDisk.H
@@ -29,7 +29,7 @@ Class
 
 Description
     Searching on circular disk given as origin, normal (gets normalised)
-    and radius
+    and radius. Optionally it can be an annular ring.
 
     \heading Dictionary parameters
     \table
@@ -38,6 +38,7 @@ Description
         origin      | centre of disk                    | yes   |
         normal      | normal vector                     | yes   |
         radius      | disk radius                       | yes   |
+        innerRadius | inner disk radius                 | no    | 0
     \endtable
 
 Note
@@ -52,6 +53,7 @@ SourceFiles
 #define searchableDisk_H
 
 #include "plane.H"
+#include "MinMax.H"
 #include "searchableSurface.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
@@ -70,10 +72,10 @@ class searchableDisk
 {
 private:
 
-    // Private Member Data
+    // Private Data
 
-        //- Radius
-        const scalar radius_;
+        //- Inner/outer radial limits
+        const scalarMinMax radialLimits_;
 
         //- Names of regions
         mutable wordList regions_;
@@ -119,7 +121,8 @@ public:
             const IOobject& io,
             const point& originPoint,
             const vector& normalVector,
-            const scalar radius
+            const scalar outerRadius,
+            const scalar innerRadius = 0
         );
 
         //- Construct from dictionary (used by searchableSurface)
@@ -247,7 +250,6 @@ public:
                 NotImplemented;
                 return false;
             }
-
 };
 
 
diff --git a/tutorials/compressible/rhoSimpleFoam/gasMixing/injectorPipe/system/fieldTransfer b/tutorials/compressible/rhoSimpleFoam/gasMixing/injectorPipe/system/fieldTransfer
index ff827d803c..cb780c9185 100644
--- a/tutorials/compressible/rhoSimpleFoam/gasMixing/injectorPipe/system/fieldTransfer
+++ b/tutorials/compressible/rhoSimpleFoam/gasMixing/injectorPipe/system/fieldTransfer
@@ -45,6 +45,25 @@ sampled
             ${_sampleMesh}
             surface     plane-0.55.stl;
         }
+
+        outerplane-0.45
+        {
+            type        distanceSurface;
+            // defaults:
+            distance    0;
+            signed      true;
+            isoMethod   topo;
+
+            surfaceType disk;
+
+            origin      (0.45 0 0);
+            normal      (1 0 0);
+            radius      0.09;
+            innerRadius 0.05;
+
+            topology    largestRegion;
+            store       true;
+        }
     }
 }
 
diff --git a/tutorials/compressible/rhoSimpleFoam/gasMixing/injectorPipe/system/samplingDebug b/tutorials/compressible/rhoSimpleFoam/gasMixing/injectorPipe/system/samplingDebug
new file mode 100644
index 0000000000..85c05bd8b3
--- /dev/null
+++ b/tutorials/compressible/rhoSimpleFoam/gasMixing/injectorPipe/system/samplingDebug
@@ -0,0 +1,66 @@
+// -*- C++ -*-
+
+// ************************************************************************* //
+
+samplingDebug
+{
+    type    surfaces;
+    libs    (sampling);
+    log     true;
+    writeControl  timeStep;
+    writeInterval 1;
+
+    fields  (tracer0 U);
+
+    sampleScheme  cellPoint;
+    interpolationScheme cellPoint;
+    surfaceFormat vtk;
+
+    formatOptions
+    {
+        ensight
+        {
+            collateTimes  true;
+            // collateTimes  false;
+        }
+    }
+
+    _sampleMesh
+    {
+        type    meshedSurface;
+        source  cells;
+    }
+
+    _diskOuter
+    {
+        surfaceType disk;
+        origin      (0 0 0);
+        normal      (1 0 0);
+        radius      0.09;
+    }
+
+    _distanceSurface
+    {
+        type        distanceSurface;
+        distance    0;
+        signed      true;
+        isoMethod   topo;
+    }
+
+    surfaces
+    {
+        diskOuter
+        {
+            ${_distanceSurface}
+            ${_diskOuter}
+
+            origin      (0.45 0 0);
+            innerRadius 0.05;
+
+            topology    largestRegion;
+        }
+    }
+}
+
+
+// ************************************************************************* //