public void ParsePressure(string pn, ReadingXLSRow row)
        {
            var found = Pressures.FirstOrDefault(x => x.MathPn(pn));

            if (found != null)
            {
                row.Pressure      = found;
                row.PressureUnits = PressureUnits.PN;
                return;
            }

            row.Pressure = Pressures.FirstOrDefault(x => x.Pclass == pn);
            if (row.Pressure != null)
            {
                row.PressureUnits = PressureUnits.Pclass;
            }
            return;
        }
        public void ParseDiameter(string dn, ReadingXLSRow row)
        {
            dn = dn.Replace("DN", "").Replace("dn", "");
            int mm;

            if (int.TryParse(dn, out mm))
            {
                var found = Diameters.FirstOrDefault(x => x.Mm == mm);
                if (found != null)
                {
                    row.Diameter      = found;
                    row.DiameterUnits = DiameterUnits.mm;
                    return;
                }
            }

            row.Diameter = Diameters.FirstOrDefault(x => x.Inch == dn);
            if (row.Diameter != null)
            {
                row.DiameterUnits = DiameterUnits.inch;
            }
            return;
        }