From a9aa752d3a611cb51ee15c2a6b94ca8c6a78e194 Mon Sep 17 00:00:00 2001
From: lbutler <lukepbutler@gmail.com>
Date: Wed, 9 Jul 2025 23:36:56 -0400
Subject: [PATCH] Fix Incorrect Conversion of Feet of Pressure to Meters

#864
---
 src/epanet.c | 11 ++++++++---
 src/input1.c |  4 ++--
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/src/epanet.c b/src/epanet.c
index e4f3683..1569305 100644
--- a/src/epanet.c
+++ b/src/epanet.c
@@ -1355,7 +1355,12 @@ int DLLEXPORT EN_setoption(EN_Project p, int option, double value)
 
     case EN_SP_GRAVITY:
         if (value <= 0.0) return 213;
-        Ucf[PRESSURE] *= (value / hyd->SpGrav);
+        if (p->parser.Pressflag == PSI || 
+            p->parser.Pressflag == KPA || 
+            p->parser.Pressflag == BAR)
+        {
+            Ucf[PRESSURE] *= (value / hyd->SpGrav);
+        }
         hyd->SpGrav = value;
         break;
 
@@ -2285,7 +2290,7 @@ int DLLEXPORT EN_getnodevalue(EN_Project p, int index, int property, double *val
         v = 0.0;
         if (Node[index].Ke > 0.0)
         {
-            ecfTmp = (parser->Unitsflag == US) ? (PSIperFT * hyd->SpGrav) : (MperFT * hyd->SpGrav);
+            ecfTmp = (parser->Unitsflag == US) ? (PSIperFT * hyd->SpGrav) : MperFT;
             v = Ucf[FLOW] / pow((ecfTmp * Node[index].Ke), (1.0 / hyd->Qexp));
         }
         break;
@@ -2533,7 +2538,7 @@ int DLLEXPORT EN_setnodevalue(EN_Project p, int index, int property, double valu
         if (value < 0.0) return 209;
         if (value > 0.0)
         {
-            ecfTmp = (parser->Unitsflag == US) ? (PSIperFT * hyd->SpGrav) : (MperFT * hyd->SpGrav);
+            ecfTmp = (parser->Unitsflag == US) ? (PSIperFT * hyd->SpGrav) : MperFT;
             value = pow((Ucf[FLOW] / value), hyd->Qexp) / ecfTmp;
         }
         Node[index].Ke = value;
diff --git a/src/input1.c b/src/input1.c
index 94a7a3e..0773e23 100644
--- a/src/input1.c
+++ b/src/input1.c
@@ -453,10 +453,10 @@ void initunits(Project *pr)
 
     strcpy(rpt->Field[PRESSURE].Units, PressUnitsTxt[parser->Pressflag]);
     pcf = PSIperFT * hyd->SpGrav; // Default to PSI
-    if (parser->Pressflag == METERS) pcf = MperFT * hyd->SpGrav;
+    if (parser->Pressflag == METERS) pcf = MperFT;
     if (parser->Pressflag == KPA)    pcf = KPAperPSI * PSIperFT * hyd->SpGrav;
     if (parser->Pressflag == BAR)    pcf = BARperPSI * PSIperFT * hyd->SpGrav;
-    if (parser->Pressflag == FEET)   pcf = 1.0 * hyd->SpGrav;
+    if (parser->Pressflag == FEET)   pcf = 1.0;
 
     strcpy(rpt->Field[QUALITY].Units, "");
     ccf = 1.0;