Solar Fluids

XCELTHERM® MK1

Chemically equivalent to DOWTHERM™ A. Recommended for Concentrated Solar Power Systems, PET production, Synthetic Fiber plants and many other applications that require a high temperature heat transfer fluid

  • Typical Properties

    Key Operating Temperatures
    Maximum Bulk Fluid Operating Temperature
    Liquid Phase 750°F 400°C
    Vapor Phase 750°F 400°C
    Maximum Film Temperature 800ºF 427ºC
    Crystallizing Point 53.6°F 12°C
    Flash Point (PMCC)(ASTM D93)(min) 230°F 110°C
    Flash Point (COC)(ASTM D92)(min) 255°F 124°C
    Fire Point (ASTM D92)(min) 260°F 127°C
    Autoignition Temperature (min) 1,150°F 621°C
    Pumpability, at 300 mm2/s (cSt) 55.4°F > 13°C
    Normal Boiling Point at 760 mm Hg 495°F 257°C
    Physical Properties
    Appearance Water-white to straw yellow liquid
    Odor Aromatic
    Composition Stable eutectic mixture of 73% Diphenyl Oxide and 27% Biphenyl
    Average Molecular Weight 166 g/mol
    Density, at 77°F/25°C 1,058 kg/m3 8.83 lbs/gal
    Specific Gravity, at 25°C (77°F) 1.06
    Moisture Content (max) 300 ppm
    Critical Temperature 930.3°F 499°C
    Critical Pressure 480.3 psia 3.31 MPa
    Critical Density 20.4 lb/ft3 327 kg/m3
    Critical Volume 0.0508 ft3/lb 3.17 L/kg
    Kinematic Viscosity, at 104°F/40°C 2.48 cSt
    Kinematic Viscosity, at 212°F/100°C 0.99 cSt
    Coefficient of Thermal Expansion, at 392°F/200°C 7.317 x 10-4/°F 9.341 x 10-4/°C
    Heat of Vaporization, at Maximum Use Temperature 123.3 BTU/lb 286.7 kJ/kg
    Volume Contraction Upon Freezing 6.30%
    Volume Expansion Upon Melting 6.66%
    Heat of Fusion 41.9 BTU/lb 97.5 kJ/kg
    Electrical Properties
    Specific Resistivity, at 68°F/20°C 6.4 x 10 ohm-cm
    Surface Tension in Air, at 77°F/ 25°C 36.6 dynes/cm
    * Data represents typical laboratory samples and are not guaranteed for all samples
  • Engineering Properties

    LIQUID PHASE*

    Temperature Viscosity Density Specific Heat Thermal
    Conductivity
    Enthalpy (Liquid)

    Vapor
    Pressure

    ºF

    ºC

    cP

    lb/ft3

    kg/m3

    BTU/lb-ºF

    J/g-K

    BTU/ft-hr-ºF

    W/m-K

    BTU/lb

    J/g

    psia

    kg/cm2

    53.6 12.0 5.708 66.8 1070.1 0.364 1.523 0.0792 0.1371 0.0 0.0 0.0001
    60 15.6 4.961 66.7 1068.5 0.366 1.532 0.0790 0.1367 2.3 5.4 0.0001
    80 26.7 3.470 66.1 1058.9 0.374 1.565 0.0784 0.1357 9.7 22.6 0.0004
    100 37.8 2.629 65.5 1049.3 0.382 1.599 0.0778 0.1347 17.3 40.2 0.0010 0.0001
    120 48.9 2.120 65.0 1041.3 0.390 1.632 0.0772 0.1336 25.0 58.2 0.0026 0.0002
    140 60.0 1.727 64.4 1031.7 0.397 1.662 0.0765 0.1324 32.9 76.4 0.0059 0.0004
    160 71.1 1.449 63.8 1022.1 0.405 1.695 0.0758 0.1312 40.9 95.1 0.0127 0.0009
    180 82.2 1.245 63.3 1014.1 0.412 1.724 0.0750 0.1298 49.0 114.0 0.0254 0.0018
    200 93.3 1.082 62.7 1004.5 0.420 1.758 0.0743 0.1286 57.4 133.4 0.0483 0.0034
    220 104.4 0.936 62.1 994.8 0.427 1.787 0.0735 0.1272 65.8 152.9 0.0872 0.0061
    240 115.6 0.822 61.5 985.2 0.435 1.821 0.0727 0.1258 74.5 173.1 0.1511 0.0106
    260 126.7 0.730 61.0 977.2 0.442 1.850 0.0719 0.1244 83.2 193.3 0.2519 0.0177
    280 137.8 0.654 60.4 967.6 0.449 1.879 0.0710 0.1229 92.0 213.9 0.4045 0.0284
    300 148.9 0.591 59.8 958.0 0.157 1.913 0.0701 0.1213 101.1 235.1 0.6288 0.0442
    320 160.0 0.537 59.2 948.4 0.464 1.942 0.0692 0.1198 110.3 256.3 0.9498 0.0668
    340 171.1 0.490 58.6 938.8 0.471 1.971 0.0683 0.1182 119.6 277.9 1.3994 0.0984
    360 182.2 0.449 58.0 929.2 0.478 2.001 0.0674 0.1167 129.0 299.8 2.0165 0.1418
    380 193.3 0.414 57.4 919.5 0.485 2.030 0.0664 0.1149 138.6 322.0 2.8489 0.2003
    400 204.4 0.383 56.8 909.9 0.492 2.059 0.0654 0.1132 148.3 344.6 3.9542 0.2780
    420 215.6 0.354 56.1 898.7 0.499 2.088 0.0644 0.1115 158.1 367.4 5.3487 0.3761
    440 226.7 0.330 55.5 889.1 0.507 2.122 0.0633 0.1096

    168.3

    391.1

    7.1500

    0.5027
    460 237.8 0.309 54.9 879.5 0.513 2.147 0.0622 0.1077 178.2 414.2 9.4113 0.6617
    480 248.9 0.289 54.2 868.3 0.521 2.180 0.0611 0.1058 188.7 438.5 12.1631 0.8552
    500 260.0 0.272 53.5 857.1 0.528 2.210 0.0600 0.1038 199.1 462.7 15.5617 1.0941
    520 271.1 0.256 52.8 845.9 0.535 2.239 0.0589 0.1019 209.6 487.2 19.8169 1.3933
    540 282.2 0.241 52.2 836.2 0.542 2.268 0.0577 0.0999 220.3 512.1 24.3956 1.7153
    560 293.3 0.228 51.4 823.4 0.549 2.298 0.0565 0.0978 231.2 537.2 30.7227 2.1601
    580 304.4 0.216 50.7 812.2 0.556 2.327 0.0553 0.0957 242.1 562.7 37.6331 2.6460
    600 315.6 0.206 50.0 801.0 0.563 2.356 0.0540 0.0935 253.3 588.6 45.7286 3.2152
    620 326.7 0.196 49.2 788.2 0.571 2.390 0.0527 0.0912

    264.8

    615.4

    55.0781

    3.8725
    640 337.8 0.186 48.4 775.4 0.578 2.419 0.0514 0.0890 276.2 641.9 65.8004 4.6264
    660 348.9 0.178 47.6 762.6 0.586 2.452 0.0501 0.0867 288.0 669.4 78.0639 5.4887
    680 360.0 0.170 46.7 748.1 0.594 2.486 0.0488 0.0845 300.0 697.3 92.1431 6.4786
    700 371.1 0.163 45.9 735.3 0.602 2.519 0.0474 0.0820 312.2 725.6 107.2571 7.5412
    720 382.2 0.156 44.9 719.3 0.612 2.561 0.0460 0.0796 325.2 755.8 125.1955 8.8025
    740 393.3 0.149 43.9 703.3 0.622 2.603 0.0446 0.0772

    338.4

    786.4

    145.5162

    10.2312
    750 398.9 0.146 43.4 695.3 0.627 2.624 0.0439 0.0760 345.1

    801.9

    156.6439

    11.0136

    VAPOR PHASE*

    Temperature Viscosity Density Specific Heat Thermal
    Conductivity
    Latent Heat Vap

    Enthalpy**

    ºF

    ºC

    cP

    lb/ft3

    kg/m3

    BTU/lb-ºF

    J/g-K

    BTU/ft-hr-ºF

    W/m-K

    BTU/lb

    J/g

    BTU/lb

    J/g

    53.6 12.0 0.00571 0.2331 0.9756 0.0103 0.0178

    180.1

    418.6

    180.1

    418.6

    60 15.6 0.00577 0.2361 0.9879 0.0103 0.0178

    179.3

    416.7

    181.6

    422.1

    80 26.7 0.00598 0.2443 1.0222 0.0103 0.0178

    176.8

    410.9

    186.5

    433.5

    100 37.8 0.00619 0.2525 1.0565 0.0104 0.0180

    174.2

    404.8

    191.5

    445.1

    105 40.6 0.00625 0.2545 1.0651 0.0104 0.0180

    173.6

    403.4

    192.8

    448.1

    110 43.3 0.00630 0.2566 1.0737 0.0104 0.0180

    173.0

    402.1

    194.2

    451.2

    115 46.1 0.00635 0.2586 1.0823 0.0104 0.0180

    172.3

    400.4

    195.4

    454.1

    120 48.9 0.00641 0.2607 1.0909 0.0104 0.0180

    171.7

    399.0

    196.7

    457.2

    140 60.0 0.00662 0.0002 0.0025 0.2689 1.1252 0.0105 0.0182

    169.2

    393.2

    202.1

    469.6

    160 71.1 0.00683 0.0003 0.0051 0.2771 1.1595 0.0106 0.0183

    166.7

    387.4

    207.6

    482.5

    180 82.2 0.00704 0.0006 0.0099 0.2853 1.1938 0.0107 0.0185

    164.2

    381.6

    213.2

    495.6

    200 93.3 0.00725 0.0011 0.0181 0.2935 1.2281 0.0108 0.0187

    161.7

    375.8

    219.1

    509.2

    220 104.4 0.00746 0.0020 0.0319 0.3017 1.2625 0.109 0.0189 159.3 370.2 225.1 523.2
    240 115.6 0.00767 0.0033 0.0535 0.3099 1.2968 0.0110 0.0190

    157.5

    366.0

    232.0

    539.1
    260 126.7 0.00788 0.0054 0.0867 0.3181 1.3311 0.0111 0.0192

    157.8

    359.8

    238.0

    553.1
    280 137.8 0.00809 0.0085 0.1355 0.3263 1.3654 0.0113 0.0196

    152.7

    354.9

    244.7

    568.8
    300 148.9 0.00830 0.0128 0.2051 0.3345 1.3997 0.0114 0.0197

    150.3

    349.3

    251.4

    584.4
    320 160.0 0.00851 0.0189 0.3028 0.3427 1.4340 0.0116 0.0201

    148.0

    344.0

    258.3

    600.3
    340 171.1 0.00872 0.0273 0.4373 0.3509 1.4684 0.0117 0.0203

    145.6

    338.4

    265.2

    616.3
    360 182.2 0.00893 0.0384 0.6152 0.3591 1.5027 0.0119 0.0206

    143.2

    332.8

    272.2

    632.6
    380 193.3 0.00915 0.0529 0.8475 0.3673 1.5370 0.0121 0.0209

    140.8

    327.2

    279.4

    649.2
    400 204.4 0.00936 0.0717 101486 0.3755 1.5713 0.0123 0.0213

    138.5

    321.9

    286.8

    666.4
    420 215.6 0.00957 0.0954 1.5283 0.3837 1.6056 0.0126 0.0218

    136.1

    316.3

    294.2

    683.7
    440 226.7 0.00978 0.1250 2.0025 03919 1.6400 0.0128 0.0222

    133.7

    310.7

    302.0

    701.8
    460 237.8 0.00999 0.1620 2.5952 0.4001 1.6743 0.0130 0.0225

    131.3

    305.1

    309.5

    719.3
    480 248.9 0.01020 0.2060 3.3001 0.4083 1.7086 0.0133 0.0230

    128.9

    299.6

    317.6

    738.1
    500 260.0 0.01041 0.2600 4.1652 0.4165 1.7429 0.0135 0.0234

    126.6

    294.2

    325.7

    756.9
    520 271.1 0.01062 0.3250 5.2065 0.4247 1.7772 0.0138 0.0239

    124.2

    288.6

    333.8

    775.9
    540 282.2 0.01083 0.4010 6.4240 0.4329 1.8115 0.0141 0.0244

    121.8

    283.1

    342.1

    795.1
    560 293.3 0.01104 0.4920 7.8818 0.4411 1.8459 0.0144 0.0249

    119.4

    277.5

    350.6

    814.7
    580 304.4 0.01125 0.5970 9.5639 0.4493 1.8802 0.0147 0.0254

    117.0

    271.9

    359.1

    834.7
    600 315.6 0.01146 0.7200 11.5344 0.4575 1.9145 0.0150 0.0260

    114.7

    266.6

    368.0

    855.1
    620 326.7 0.01168 0.8620 13.8092 0.4657 1.9488 0.0153 0.0265

    111.7

    259.6

    376.5

    875.0
    640 337.8 0.01189 1.0300 16.5006 0.4739 1.9831 0.0157 0.0272

    108.3

    251.7

    384.5

    893.6
    660 348.9 0.01210 1.2200 19.5444 0.4821 2.0175 0.0160 0.0277

    104.9

    243.8

    392.9

    913.2
    680 360.0 0.0131 1.4300 22.9086 0.4903 2.0518 0.0164 0.0284

    101.5

    235.9

    401.5

    933.2
    700 371.1 0.01252 1.6800 26.9136 0.4985 2.0861 0.0168 0.0291

    98.1

    228.0

    410.3

    953.6
    720 382.2 0.01273 1.9600 31.3992 0.5067 2.1204 0.0171 0.0296

    94.7

    220.1

    419.9

    975.9
    740 393.3 0.01294 2.2900 36.6858 0.5149 2.1547 0.0176 0.0305

    91.3

    212.2

    429.7

    998.6
    750 398.9 0.01305 2.4700 39.5694 0.5190 2.1719 0.0178 0.0308

    89.6

    208.2

    434.7

    1010.2

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