| HS Code | 550286 |
| Productname | Cooling Liquid Products RH-PCT-50 |
| Manufacturer | Cooling Liquid Products |
| Productcode | RH-PCT-50 |
| Productcategory | Propylene glycol heat transfer fluid/coolant |
| Basefluid | Propylene glycol |
| Formulation | Premixed 50% propylene glycol with corrosion inhibitors |
| Recommendeduse | Closed-loop radiant heating/cooling, HVAC, snowmelt, and geothermal systems |
| Appearance | Pink liquid |
| Odor | Mild |
| Ph | 8.0 to 9.5 |
| Specificgravity | Approximately 1.04 at 20 °C |
| Freezingpoint | Approximately -30 °F (-34 °C) |
| Boilingpoint | Approximately 225 °F (107 °C) |
| Viscosity | Approximately 4 to 6 cSt at 20 °C |
| Flashpoint | > 200 °F (93 °C) |
| Watersolubility | Fully soluble |
| Storagetemperature | 5 to 40 °C (41 to 104 °F) |
| Shelflife | 24 months in sealed container |
| Packaging | Pails, drums, and totes |
| Corrosioninhibitorpackage | Contains corrosion inhibitors for common metals |
As an accredited Cooling Liquid Products RH-PCT-50 factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Cooling Liquid Products RH-PCT-50 is supplied in sealed 20 L high-density polyethylene containers with secure closures and clear labels. |
| Container Loading (20′ FCL) | 20′ FCL container loaded with Cooling Liquid Products RH-PCT-50 in sealed drums, properly labeled, secured, and stowed for safe transport. |
| Shipping | Cooling Liquid Products RH-PCT-50 should be shipped in sealed, compatible containers with proper labeling and documentation. Keep upright, dry, and protected from freezing, heat, and impact. Transport in a well-ventilated vehicle according to local, national, and international regulations, and follow the current SDS and transport classification before shipment. |
| Storage | Store **Cooling Liquid Products RH-PCT-50** in a cool, dry, well-ventilated area away from direct sunlight, heat, ignition sources, and incompatible chemicals. Keep containers tightly closed, properly labeled, and upright to prevent leakage. Protect from freezing and physical damage. Use secondary containment where required, and follow local regulations and the supplier’s safety data sheet. |
| Shelf Life | Shelf life is typically 24 months from date of manufacture when stored unopened in original packaging under recommended conditions. |
For high-density server racks, direct-to-chip liquid cooling loops impose a bulk conductivity limit of 2.0–10.0 µS/cm because the cold plate is electrically adjacent to CPU and GPU package substrates. RH-PCT-50 is diluted to 25 vol% with deionized water meeting ASTM D1193 Type IV resistivity above 18 MΩ·cm at 25°C; a higher glycol content raises viscosity and reduces heat transfer at the boundary layer, while a lower content reduces reserve alkalinity and weakens metal passivation. The fluid is charged through a 10 µm absolute fill filter, and online bypass filtration uses 3 µm β₃≥200 cartridges to maintain particle counts below ISO 4406 17/15/12. Circulation velocity in microchannel cold plates with hydraulic diameters below 1.0 mm is maintained between 0.5 m/s and 1.5 m/s to avoid laminar stagnation while limiting erosion-corrosion of copper lands. Cold plate inlet temperature is controlled to 45°C ± 1°C to stay above the data hall dew point while maintaining chip case temperature below 85°C. Corrosion control is verified per ASTM D1384 using six metal coupons at 88°C for 336 h; the more decisive acceptance criterion is conductivity drift measured by ASTM D1125 and copper/zinc galvanic current per ASTM G31-72(2010). Galvanized piping is incompatible because zinc dissolution raises conductivity; stainless steel, copper, or PEX are acceptable wetted materials. Field validation on a 120 kW rack with a 300 kW dry cooler and continuous resistivity logging is recommended before multi-rack deployment. The terminal finished product is a sealed server manifold with brazed copper cold plates over CPU and GPU lids; the coolant circulates inside the data hall as a process fluid rather than a visible end-user article.
Wet-sleeve diesel engines subject the coolant film on the liner exterior to cavitation collapse driven by cylinder pressure fluctuation; nitrite and molybdate inhibitors deposit a protective oxide-nitride film that reduces liner pitting rate in heavy-duty operation. RH-PCT-50 is charged at 50 vol% with purified water conforming to ASTM D3306 or ASTM D6210 base water requirements; the final fill is checked for freeze point below −37°C by ASTM D1177 and for reserve alkalinity above 10 mL 0.1 N HCl per 10 mL sample by ASTM D1121. Concentration drift is a known field failure: concentrations below 40 vol% reduce cavitation protection and raise water pump seal wear, while concentrations above 60 vol% lower heat transfer and accelerate glycol oxidation. On the production line, the coolant is vacuum-filled through the radiator to minimize air pockets, then the engine is run at 1,000–1,500 rpm until the thermostat opens to eliminate trapped vapor. The terminal finished product is a heavy-duty truck or stationary gen-set engine with protected liner O-ring grooves, water pump seals, and copper-brass oil cooler tubes. Published test data for RH-PCT-50 under prolonged ultrasonic cavitation is limited; if the application requires formal cavitation qualification, a liner coupon test program should be executed before fleet-wide fill.
In lithium-ion battery cold plate loops, a bulk conductivity ceiling of 10 µS/cm is required to avoid stray-current corrosion of nickel-plated busbars and aluminum cold plates. RH-PCT-50 is diluted to 33 vol% in deionized water of 1 MΩ·cm minimum resistivity; the dilution ratio balances freeze protection at −20°C against viscosity rise at −40°C and pump energy demand. The fluid is circulated through an extruded aluminum cold plate with 8 mm serpentine channels at a flow rate of 8–12 L/min per module and a pressure drop below 25 kPa. A vacuum fill station applies −0.8 bar to remove trapped air, followed by a helium leak test at 1.5 bar for 30 s. Amine-based corrosion inhibitors should not be added; amine decomposition products can react with the aluminum passivation layer and increase ionic load. Corrosion resistance is checked per ASTM D1384 using aluminum, copper, brass, steel, cast iron, and solder coupons, with aluminum mass loss not exceeding 30 mg per specimen. The terminal finished product is a sealed battery pack for stationary storage or an electric bus, with the coolant contained in a welded aluminum circuit and isolated from cell tabs. Published data for RH-PCT-50 under ISO 6469-1 electrical isolation requirements is limited; pack-level validation should include dielectric strength testing of the drained cold plate after 1,000 h circulation at 60°C.
Jacketed stainless steel batch reactors expose the coolant to return temperatures up to 120°C at the reactor wall, which accelerates oxidative degradation of unprotected glycol unless the formulation carries a high-temperature inhibitor package. RH-PCT-50 is diluted to 35 vol% with softened water of <50 mg/L total hardness as CaCO₃; the solution is charged into a closed-loop temperature control unit with an expansion vessel blanketed under nitrogen at 0.2 bar positive pressure. The process fluid is circulated at 20–30 L/min through a plate-and-frame heat exchanger with 0.5 m² transfer area per 100 kW cooling load, and the bulk temperature is held by a modulated cooling water bypass. Corrosion inhibition is monitored by monthly coupon racks per ASTM G31-72(2010) and by pH maintained above 8.0 per ASTM D1287. Amine-based supplemental inhibitors must not be introduced into the same circuit; amine breakdown products foul reactor jackets and raise maintenance frequency. The terminal finished product is the reactor effluent—typically a batch polymer resin, ester intermediate, or pigment dispersion—whose quality depends on jacket temperature uniformity and absence of metal ions leached from the cooling circuit. Published data for RH-PCT-50 in continuous 120°C return service is limited; users should monitor organic acid formation by ion chromatography at 500 h intervals.
During off-peak ice storage charging, secondary refrigerant is held at −30°C to −40°C; the pumpability limit is therefore set not by freezing point alone but by viscosity at −30°C, which must remain below 50 mPa·s for centrifugal pumps. RH-PCT-50 is proportioned at 40 vol% to 45 vol% with softened water, and the resulting solution is checked for freeze point by ASTM D1177 and for kinematic viscosity by ASTM D445 at −30°C. The fluid is circulated at 3–5 m/s in carbon steel piping, through brazed plate heat exchangers with 0.8 mm plate spacing; the fill is pre-filtered with 25 µm bag filters and then maintained with 5 µm inline filters to protect pump seals. Concentrations above 50 vol% are avoided because viscosity at −30°C exceeds the capacity of standard end-suction pumps and heat transfer declines. The terminal finished product is the chilled water thermal storage system itself, with the secondary fluid isolated from the brine side by a heat exchanger. Published data for RH-PCT-50 at −40°C is limited; a low-temperature tube viscometer and glycol degradation screening are recommended if the system is to be charged below −35°C.
PEM fuel cell coolant must maintain ionic contamination below 0.5 µS/cm after contact with the bipolar plate, because soluble ions migrate into the membrane and reduce proton conductivity. RH-PCT-50 is diluted to 10 vol% to 25 vol% with ultrapure water of 0.1 µS/cm or lower; the lower concentration applies to stacks with graphite plates, the higher to metallic bipolar plate stacks with coated stainless steel. The loop contains an ion-exchange bypass bed sized for 10% of total flow, and the coolant is recirculated after deionization until conductivity stabilizes below 1.0 µS/cm per ASTM D1125. Because glycol degradation products such as formic acid and glycolic acid raise conductivity, the formulation must be qualified by ASTM D1384 and long-term ion leaching at 80°C for 1,000 h. Ethylene glycol concentrations above 25 vol% are generally incompatible with membrane humidification balance and may accelerate silicate dissolution from graphite plates. The terminal finished product is the assembled fuel cell stack for stationary power or material handling vehicles, with the coolant circulating through a closed loop isolated from the hydrogen side. Published data for RH-PCT-50 in fuel cell loops is limited; a stack supplier qualification program is required before use.
| Application | Dilution in deionized/softened water | Bulk conductivity limit | Principal standard method | Terminal finished product |
|---|---|---|---|---|
| Data center cold plate | 25 vol% | 2.0–10.0 µS/cm | ASTM D1125 | Sealed server manifold |
| Heavy-duty diesel | 50 vol% | conductivity not specified | ASTM D6210 | Wet-sleeve engine |
| Battery cold plate | 33 vol% | 10 µS/cm | ASTM D1125 | Sealed battery pack |
| Jacketed reactor | 35 vol% | conductivity not specified | ASTM D1287 | Batch polymer or chemical intermediate |
| Ice storage secondary refrigerant | 40–45 vol% | not applicable | ASTM D1177 | Thermal storage system |
| Fuel cell loop | 10–25 vol% | <0.5 µS/cm | ASTM D1125 | Fuel cell stack |
Unlike automotive engine cooling circuits, traction inverter cold plates require the coolant to contact nickel-plated copper and aluminum nitride substrates without forming a conductive film. RH-PCT-50 is diluted to 30 vol% with deionized water of 5 µS/cm initial conductivity, then the cold plate loop is flushed until the conductivity is below 10 µS/cm. The fluid is pumped at 4–6 L/min through a pin-fin copper cold plate with a pressure drop below 15 kPa; the inlet temperature is held at 40°C to 50°C, and the outlet temperature is maintained below 65°C to protect the silicon carbide die. Corrosion compatibility is verified per ASTM D1384 and electrochemical impedance spectroscopy on copper and aluminum coupled coupons at 80°C for 500 h. The terminal finished product is a sealed inverter module for electric bus or wind converter, with the cold plate joined by vacuum brazing and verified by helium leak test. Published data for RH-PCT-50 in pin-fin geometries with copper-aluminum bimetallic junctions is limited.
Competitive Cooling Liquid Products RH-PCT-50 prices that fit your budget—flexible terms and customized quotes for every order.
For samples, pricing, or more information, please contact us at +8618005193850 or mail to sales8@bouling-chem.com.
We will respond to you as soon as possible.
Tel: +8618005193850
Email: sales8@bouling-chem.com
Flexible payment, competitive price, premium service - Inquire now!
Cooling Liquid Products RH-PCT-50 is a water-dilutable, phosphate-free, nitrite-free and silicate-free heat transfer fluid formulated from propylene glycol, demineralised water and an organic acid corrosion inhibitor package. The concentrate is intended for closed-loop industrial cooling circuits, stationary engine jacket cooling, and cold-plate cooling of power electronics where low electrical conductivity and protection of aluminium alloys are concurrent requirements. It is supplied as a concentrate with a typical density of 1.055 g/cm³ at 20 °C and a refractive index of 1.3710 at 20 °C. The product is not intended for potable water systems or for open recirculating cooling towers without additional biocide and filtration management.
The following values are manufacturer release limits for fresh concentrate and for 50 vol% dilution with deionised water. Field samples may vary with dilution water quality, glycol oxidation products, and system contamination.
| Property | Test Method | Value |
|---|---|---|
| Density at 20 °C | ASTM D1122 | 1.055 g/cm³ |
| Refractive index at 20 °C | ASTM D1218 | 1.3710 |
| pH of concentrate | ASTM D1287 | 8.2 |
| Reserve alkalinity, concentrate | ASTM D1121 | 8.0 mL 0.100 N HCl to pH 5.5 |
| Kinematic viscosity at 20 °C, concentrate | ASTM D445 | 58 mm²/s |
| Kinematic viscosity at 20 °C, 50 vol% dilution | ASTM D445 | 4.8 mm²/s |
| Freezing point, 50 vol% dilution | ASTM D1177 | -35 °C |
| Boiling point, 50 vol% dilution at 101.3 kPa | ASTM D1120 | 108 °C |
| Specific heat capacity, 50 vol% at 80 °C | ASTM E1269 | 3.4 kJ/(kg·K) |
| Thermal conductivity, 50 vol% at 80 °C | ISO 22007-2 | 0.41 W/(m·K) |
| Electrical conductivity, 50 vol% at 25 °C | ASTM D1125 | 165–190 µS/cm |
| Corrosion weight loss, mixed metal | ASTM D1384 | Cu <10 mg, solder <30 mg, brass <10 mg, steel <10 mg, cast iron <10 mg, aluminium <30 mg |
For central chiller distribution networks using a suction-line pump and open expansion tank, the net positive suction head available must exceed pump net positive suction head required by at least 1 m at maximum summer fluid temperature. The viscosity of RH-PCT-50 concentrate at -10 °C is approximately 145 mm²/s; direct pumping of undiluted concentrate at low temperature is therefore not recommended. Dilute first to at least 40 vol% before filling winterised systems. A positive-displacement transfer pump with 10 bar minimum discharge pressure is standard for concentrate dosing into large circuits.
In indirect liquid cooling of insulated-gate bipolar transistor stacks, the coolant can become part of the electrical leakage path when the fluid circulates through uninsulated copper cold plates at bus potentials above 400 V. In such circuits, fluid electrical conductivity above 500 µS/cm at 25 °C is treated as a maintenance threshold in several power module commissioning procedures. RH-PCT-50 diluted to 50 vol% with demineralised water exhibits an initial conductivity of 165–190 µS/cm at 25 °C by ASTM D1125. The value rises with glycol oxidation products, chloride ingress from poor-quality make-up water, and dissolved carbon dioxide absorption in vented systems. For high-voltage indirect cooling, a closed expansion tank with a nitrogen blanket and a conductivity sensor with a 200 µS/cm alarm setpoint is required. Systems using plate-and-frame heat exchangers with 0.4 mm thin stainless steel plates should not exceed 90 °C bulk fluid temperature to avoid localised nucleate boiling at plate contact points. The low initial electrical conductivity differentiates RH-PCT-50 from conventional phosphate-containing coolants, which typically exceed 1,800 µS/cm at the same dilution due to inorganic salt dissociation.
Thermal degradation of propylene glycol begins at hot metal skin temperatures above 135 °C. In pressurised closed loops, the bulk fluid temperature can be maintained below the atmospheric boiling point, but heater jacket or mould-channel hot spots can still exceed local saturated liquid temperature. For RH-PCT-50 at 50 vol%, the supplier-documented maximum continuous bulk temperature is 95 °C at atmospheric pressure and 120 °C under a 1.5 bar system cap. Above this range, glycol oxidises to formic acid and glycolic acid; the resulting pH drop below 7.0 depletes the carboxylate inhibitor reserve and accelerates mixed-metal galvanic corrosion. In heater loops with cartridge heater surface heat flux above 12 W/cm², a plate-fin heat exchanger with 316L stainless steel construction is preferred over copper-brazed units. Operators should measure pressure drop and pH weekly when the loop is operated above 90 °C. Published data for this specific configuration is limited, but field reports from injection moulding lines indicate that bulk fluid temperature excursions above 105 °C without pressure compensation are the main cause of brown discoloration within 500 h.
In mold-temperature control units operating with turbulent flow, the selection of a water-glycol coolant affects pressure drop, heat transfer coefficient and pump energy. RH-PCT-50 at 50 vol% has a kinematic viscosity of 4.8 mm²/s at 20 °C and 1.6 mm²/s at 80 °C by ASTM D445. This is lower than many silicate-containing formulations at equivalent freeze protection, which reduces tube-side pressure drop in small-diameter mould channels. A turbulent Reynolds number above 4000 in an 8 mm internal diameter cooling channel requires a flow velocity of approximately 0.6 m/s at 80 °C; the same circuit with a high-viscosity silicate coolant may require 0.75 m/s and higher pump work. The absence of silicate gel reduces the risk of deposit formation on hot mould surfaces above 130 °C observed in oil-heated or high-temperature water systems.
At 50 vol% and 80 °C, specific heat capacity is 3.4 kJ/(kg·K) and thermal conductivity is 0.41 W/(m·K) measured by ASTM E1269 and ISO 22007-2 respectively. This yields a volumetric heat capacity approximately 8 % lower than water at the same temperature. A heat exchanger sized for water at 200 L/min must be increased by 8–10 % in surface area or coolant flow when the same duty is performed with 50 vol% glycol solution. This difference is not product-specific but is a consequence of water-glycol thermophysical properties.
Phosphate-based inhibitors protect ferrous metals by forming an iron phosphate film, but they react with calcium in hard water to produce calcium phosphate scale on heat transfer surfaces. In aluminium brazed heat exchangers, phosphate films are less stable than carboxylate films at pH above 8.0, and phosphate can accelerate aluminium transport in the presence of chloride. RH-PCT-50 replaces inorganic phosphate with a synergistic blend of sebacate and tolyltriazole inhibitors, which passivate aluminium and copper without scale-forming phosphate residues. The formulation is compatible with make-up water hardness up to 250 mg/L as CaCO₃, provided the dilution water pH is below 8.5. Above this hardness, calcium glycolate and calcium sebacate precipitation can occur in dead zones. The product should not be mixed with phosphate-containing coolants because the resulting phosphate-calcium deposit potential is higher than the weighted average of either coolant alone. This incompatibility is a documented service limitation; full system flushing with demineralised water is required before conversion.
In closed-loop engine jacket service, RH-PCT-50 at 50 vol% meets the corrosion protection requirements of ASTM D3306-23 and ASTM D4985-18 for aluminium, cast iron, steel, brass and solder. The product is not compatible with magnesium alloy components; galvanic corrosion of magnesium can occur if the coolant is exposed to uncoated magnesium water pump housings or valve covers. It should not be combined with amine-based additives, which can form insoluble carboxylate-amine complexes and reduce inhibitor availability. For engines with wet-sleeve cylinder liners, continuous coolant velocity below 0.3 m/s around the liner is a known cavitation risk; RH-PCT-50 does not eliminate this risk and supplementary nitrite-based supplemental coolant additive may be required under the engine manufacturer’s specific cavitation protection protocol.
The carboxylate inhibitor reserve in RH-PCT-50 is measured by reserve alkalinity per ASTM D1121. Fresh 50 vol% coolant has a reserve alkalinity of 8.0 mL of 0.100 N hydrochloric acid to pH 5.5. Field electrolyte depletion typically occurs faster in systems with high copper surface area and continuous air ingestion. A maintenance limit of 2.5 mL is applied for loops with mixed aluminium and copper; below this limit, inhibitor replenishment or full replacement is required. Inhibitor depletion is not directly visible by colour, so pH and conductivity alone are insufficient; ASTM D1121 titration or ion chromatography for sebacate anion should be performed quarterly. In centralised systems with variable flow, side-stream sampling from the lowest-flow branch is required because inhibitor-depleted water can stratify in stagnant zones. The product is miscible with demineralised water in all proportions, but dilution below 25 vol% removes meaningful freeze protection and reduces inhibitor concentration below the minimum effective level. For systems operating below -20 °C, a dilution of 60 vol% to 65 vol% is required; the freezing point curve is non-linear and should be confirmed by ASTM D1177 rather than by refractometer alone.
Comparison with conventional silicate-containing and phosphate-based coolants indicates the operational differences of RH-PCT-50 in closed-loop service.
| Performance Parameter | RH-PCT-50 50 vol% | Phosphate-Based Automotive Coolant 50 vol% | Silicated Heavy-Duty Coolant 50 vol% |
|---|---|---|---|
| Inhibitor chemistry | Carboxylate and tolyltriazole | Phosphate, nitrite, borate | Silicate, nitrite, molybdate |
| Electrical conductivity at 25 °C | 165–190 µS/cm | 1,800–2,500 µS/cm | 1,200–1,800 µS/cm |
| Reserve alkalinity | 8.0 mL by ASTM D1121 | 12.0 mL by ASTM D1121 | 10.0 mL by ASTM D1121 |
| Aluminium weight loss limit | <30 mg by ASTM D1384 | <30 mg by ASTM D1384 | <30 mg by ASTM D1384 |
| Hard water tolerance | 250 mg/L as CaCO₃ | <100 mg/L due to phosphate scale | <150 mg/L due to silicate gelation with calcium |
| Typical closed-loop service interval | 4 years or 6,000 h | 2 years or 3,000 h | 2 years or 4,000 h |
| Uncoated magnesium compatibility | No | No | No |
| Hot surface deposit tendency above 130 °C | Low | Moderate due to phosphate scale | High due to silicate gelation |
The comparison is based on typical published values for passenger car and heavy-duty coolants under ASTM D3306-23 and ASTM D4985-18 test conditions. Field performance may shift with dilution water chemistry, glycol degradation products, and soldering flux residues. Direct substitution of RH-PCT-50 into an existing silicated heavy-duty system without flushing is not recommended because residual silicate can react with the carboxylate package and form a gel layer on hot surfaces. A rinse protocol using 80 °C demineralised water for 45 min at full pump flow is the minimum pre-conversion procedure. The system should be analysed for silicate concentration below 25 mg/L as SiO₂ before the new fill is introduced.
Concentrate should be stored in sealed HDPE or 316L stainless steel containers below 40 °C. Exposure to continuous sunlight and open storage leads to oxidation and carbon dioxide absorption, raising conductance and lowering pH. Partially emptied drums must be blanketed with dry nitrogen or filled to minimum headspace. Freeze-thaw stability is indicated by a concentrate pour point of -35 °C; one freeze-thaw cycle without agitation can separate polymer inhibitors but gentle circulation restores full inhibitor solubility. Do not use galvanised containers; zinc dissolution can reach 50 mg/L in 30 days and poison carboxylate inhibitors.
Dedicated to excellence in chemistry — serving industries worldwide with integrity and innovation.
