diff --git a/CMakeLists_files.cmake b/CMakeLists_files.cmake
index c7f2e1cab..0ad6e9d0b 100644
--- a/CMakeLists_files.cmake
+++ b/CMakeLists_files.cmake
@@ -104,6 +104,7 @@ list (APPEND MAIN_SOURCE_FILES
   opm/simulators/wells/VFPProdProperties.cpp
   opm/simulators/wells/VFPInjProperties.cpp
   opm/simulators/wells/WellConvergence.cpp
+  opm/simulators/wells/WellGroupConstraints.cpp
   opm/simulators/wells/WellGroupControls.cpp
   opm/simulators/wells/WellGroupHelpers.cpp
   opm/simulators/wells/WellHelpers.cpp
@@ -386,6 +387,7 @@ list (APPEND PUBLIC_HEADER_FILES
   opm/simulators/wells/VFPProperties.hpp
   opm/simulators/wells/WellConnectionAuxiliaryModule.hpp
   opm/simulators/wells/WellConvergence.hpp
+  opm/simulators/wells/WellGroupConstraints.hpp
   opm/simulators/wells/WellGroupControls.hpp
   opm/simulators/wells/WellGroupHelpers.hpp
   opm/simulators/wells/WellHelpers.hpp
diff --git a/opm/simulators/wells/WellGroupConstraints.cpp b/opm/simulators/wells/WellGroupConstraints.cpp
new file mode 100644
index 000000000..3bfedfb28
--- /dev/null
+++ b/opm/simulators/wells/WellGroupConstraints.cpp
@@ -0,0 +1,94 @@
+/*
+  Copyright 2017 SINTEF Digital, Mathematics and Cybernetics.
+  Copyright 2017 Statoil ASA.
+  Copyright 2018 IRIS
+
+  This file is part of the Open Porous Media project (OPM).
+
+  OPM is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  OPM is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with OPM.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+#include <opm/simulators/wells/WellGroupConstraints.hpp>
+
+#include <opm/core/props/BlackoilPhases.hpp>
+
+#include <opm/input/eclipse/Schedule/Schedule.hpp>
+
+#include <opm/simulators/wells/WellGroupHelpers.hpp>
+#include <opm/simulators/wells/WellInterfaceGeneric.hpp>
+#include <opm/simulators/wells/WellState.hpp>
+
+namespace Opm
+{
+
+std::pair<bool, double>
+WellGroupConstraints::
+checkGroupConstraintsInj(const Group& group,
+                         const WellState& well_state,
+                         const GroupState& group_state,
+                         const double efficiencyFactor,
+                         const Schedule& schedule,
+                         const SummaryState& summaryState,
+                         const RateConvFunc& rateConverter,
+                         DeferredLogger& deferred_logger) const
+{
+    // Translate injector type from control to Phase.
+    const auto& well_controls = well_.wellEcl().injectionControls(summaryState);
+    auto injectorType = well_controls.injector_type;
+    Phase injectionPhase;
+    switch (injectorType) {
+    case InjectorType::WATER:
+    {
+        injectionPhase = Phase::WATER;
+        break;
+    }
+    case InjectorType::OIL:
+    {
+        injectionPhase = Phase::OIL;
+        break;
+    }
+    case InjectorType::GAS:
+    {
+        injectionPhase = Phase::GAS;
+        break;
+    }
+    default:
+        throw("Expected WATER, OIL or GAS as type for injector " + well_.name());
+    }
+
+    // Make conversion factors for RESV <-> surface rates.
+    std::vector<double> resv_coeff(well_.phaseUsage().num_phases, 1.0);
+    rateConverter(0, well_.pvtRegionIdx(), resv_coeff); // FIPNUM region 0 here, should use FIPNUM from WELSPECS.
+
+    const auto& ws = well_state.well(well_.indexOfWell());
+    // Call check for the well's injection phase.
+    return WellGroupHelpers::checkGroupConstraintsInj(well_.name(),
+                                                      well_.wellEcl().groupName(),
+                                                      group,
+                                                      well_state,
+                                                      group_state,
+                                                      well_.currentStep(),
+                                                      well_.guideRate(),
+                                                      ws.surface_rates.data(),
+                                                      injectionPhase,
+                                                      well_.phaseUsage(),
+                                                      efficiencyFactor,
+                                                      schedule,
+                                                      summaryState,
+                                                      resv_coeff,
+                                                      deferred_logger);
+}
+
+} // namespace Opm
diff --git a/opm/simulators/wells/WellGroupConstraints.hpp b/opm/simulators/wells/WellGroupConstraints.hpp
new file mode 100644
index 000000000..c9739feab
--- /dev/null
+++ b/opm/simulators/wells/WellGroupConstraints.hpp
@@ -0,0 +1,68 @@
+/*
+  Copyright 2017 SINTEF Digital, Mathematics and Cybernetics.
+  Copyright 2017 Statoil ASA.
+  Copyright 2017 IRIS
+  Copyright 2019 Norce
+
+  This file is part of the Open Porous Media project (OPM).
+
+  OPM is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  OPM is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with OPM.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+
+#ifndef OPM_WELL_GROUP_CONSTRAINTS_HEADER_INCLUDED
+#define OPM_WELL_GROUP_CONSTRAINTS_HEADER_INCLUDED
+
+#include <functional>
+#include <utility>
+#include <vector>
+
+namespace Opm
+{
+
+class DeferredLogger;
+class Group;
+class GroupState;
+enum class InjectorType;
+using RegionId = int;
+class Schedule;
+class SummaryState;
+class WellInterfaceGeneric;
+class WellState;
+
+//! \brief Class for computing well group constraints.
+class WellGroupConstraints {
+public:
+    //! \brief Constructor sets reference to well.
+    WellGroupConstraints(const WellInterfaceGeneric& well) : well_(well) {}
+
+    using RateConvFunc = std::function<void(const RegionId, const int, std::vector<double>&)>;
+
+    std::pair<bool, double>
+    checkGroupConstraintsInj(const Group& group,
+                             const WellState& well_state,
+                             const GroupState& group_state,
+                             const double efficiencyFactor,
+                             const Schedule& schedule,
+                             const SummaryState& summaryState,
+                             const RateConvFunc& rateConverter,
+                             DeferredLogger& deferred_logger) const;
+
+private:
+    const WellInterfaceGeneric& well_; //!< Reference to well interface
+};
+
+}
+
+#endif // OPM_WELL_GROUP_CONSTRAINTS_HEADER_INCLUDED
diff --git a/opm/simulators/wells/WellInterfaceFluidSystem.cpp b/opm/simulators/wells/WellInterfaceFluidSystem.cpp
index 0ba58228f..0a87a0481 100644
--- a/opm/simulators/wells/WellInterfaceFluidSystem.cpp
+++ b/opm/simulators/wells/WellInterfaceFluidSystem.cpp
@@ -22,16 +22,19 @@
 #include <config.h>
 #include <opm/simulators/wells/WellInterfaceFluidSystem.hpp>
 
-#include <opm/material/fluidsystems/BlackOilFluidSystem.hpp>
+#include <opm/grid/utility/RegionMapping.hpp>
 
 #include <opm/input/eclipse/Schedule/Schedule.hpp>
 
+#include <opm/material/fluidsystems/BlackOilFluidSystem.hpp>
+
 #include <opm/simulators/utils/DeferredLogger.hpp>
 #include <opm/simulators/wells/GroupState.hpp>
 #include <opm/simulators/wells/ParallelWellInfo.hpp>
 #include <opm/simulators/wells/RateConverter.hpp>
 #include <opm/simulators/wells/SingleWellState.hpp>
 #include <opm/simulators/wells/TargetCalculator.hpp>
+#include <opm/simulators/wells/WellGroupConstraints.hpp>
 #include <opm/simulators/wells/WellGroupControls.hpp>
 #include <opm/simulators/wells/WellGroupHelpers.hpp>
 #include <opm/simulators/wells/WellState.hpp>
@@ -324,64 +327,6 @@ checkIndividualConstraints(SingleWellState& ws,
     return false;
 }
 
-template <typename FluidSystem>
-std::pair<bool, double>
-WellInterfaceFluidSystem<FluidSystem>::
-checkGroupConstraintsInj(const Group& group,
-                         const WellState& well_state,
-                         const GroupState& group_state,
-                         const double efficiencyFactor,
-                         const Schedule& schedule,
-                         const SummaryState& summaryState,
-                         DeferredLogger& deferred_logger) const
-{
-    // Translate injector type from control to Phase.
-    const auto& well_controls = this->well_ecl_.injectionControls(summaryState);
-    auto injectorType = well_controls.injector_type;
-    Phase injectionPhase;
-    switch (injectorType) {
-    case InjectorType::WATER:
-    {
-        injectionPhase = Phase::WATER;
-        break;
-    }
-    case InjectorType::OIL:
-    {
-        injectionPhase = Phase::OIL;
-        break;
-    }
-    case InjectorType::GAS:
-    {
-        injectionPhase = Phase::GAS;
-        break;
-    }
-    default:
-        throw("Expected WATER, OIL or GAS as type for injector " + name());
-    }
-
-    // Make conversion factors for RESV <-> surface rates.
-    std::vector<double> resv_coeff(phaseUsage().num_phases, 1.0);
-    rateConverter_.calcInjCoeff(0, pvtRegionIdx_, resv_coeff); // FIPNUM region 0 here, should use FIPNUM from WELSPECS.
-
-    const auto& ws = well_state.well(this->index_of_well_);
-    // Call check for the well's injection phase.
-    return WellGroupHelpers::checkGroupConstraintsInj(name(),
-                                                      well_ecl_.groupName(),
-                                                      group,
-                                                      well_state,
-                                                      group_state,
-                                                      current_step_,
-                                                      guide_rate_,
-                                                      ws.surface_rates.data(),
-                                                      injectionPhase,
-                                                      phaseUsage(),
-                                                      efficiencyFactor,
-                                                      schedule,
-                                                      summaryState,
-                                                      resv_coeff,
-                                                      deferred_logger);
-}
-
 template <typename FluidSystem>
 std::pair<bool, double>
 WellInterfaceFluidSystem<FluidSystem>::
@@ -427,6 +372,11 @@ checkGroupConstraints(WellState& well_state,
     const int well_index = index_of_well_;
     auto& ws = well_state.well(well_index);
 
+    auto rCoeff = [this](const int id, const int region, std::vector<double>& coeff)
+    {
+        this->rateConverter().calcCoeff(id, region, coeff);
+    };
+
     if (well.isInjector()) {
         const auto currentControl = ws.injection_cmode;
 
@@ -440,8 +390,15 @@ checkGroupConstraints(WellState& well_state,
             const auto& group = schedule.getGroup( well.groupName(), current_step_ );
             const double efficiencyFactor = well.getEfficiencyFactor();
             const std::pair<bool, double> group_constraint =
-                checkGroupConstraintsInj(group, well_state, group_state, efficiencyFactor,
-                                         schedule, summaryState, deferred_logger);
+                WellGroupConstraints(*this).
+                    checkGroupConstraintsInj(group,
+                                             well_state,
+                                             group_state,
+                                             efficiencyFactor,
+                                             schedule,
+                                             summaryState,
+                                             rCoeff,
+                                             deferred_logger);
             // If a group constraint was broken, we set the current well control to
             // be GRUP.
             if (group_constraint.first) {
diff --git a/opm/simulators/wells/WellInterfaceFluidSystem.hpp b/opm/simulators/wells/WellInterfaceFluidSystem.hpp
index 26dbfd73c..abf8a222f 100644
--- a/opm/simulators/wells/WellInterfaceFluidSystem.hpp
+++ b/opm/simulators/wells/WellInterfaceFluidSystem.hpp
@@ -89,14 +89,6 @@ protected:
                                                    const SummaryState& summaryState,
                                                    DeferredLogger& deferred_logger) const;
 
-    std::pair<bool, double> checkGroupConstraintsInj(const Group& group,
-                                                     const WellState& well_state,
-                                                     const GroupState& group_state,
-                                                     const double efficiencyFactor,
-                                                     const Schedule& schedule,
-                                                     const SummaryState& summaryState,
-                                                     DeferredLogger& deferred_logger) const;
-
     std::pair<bool, double> checkGroupConstraintsProd(const Group& group,
                                                       const WellState& well_state,
                                                       const GroupState& group_state,