Marvell Heat Transfer Oil 25_200L Thermal Fluid

Marvell Heat Transfer Oil 25 200L is a high-performance mineral-based thermal fluid designed for industrial heat transfer systems, closed indirect heating circuits and process heating applications requiring a light 25 cSt heat transfer oil. It is formulated from highly refined mineral base stocks selected for resistance to thermal cracking, chemical oxidation and deposit formation under recommended operating conditions. This product is designed to provide efficient heat transfer, reliable pumpability and stable circulation in systems where consistent temperature control, long service life and dependable thermal performance are required.

This 200L drum size is suitable for industrial users, maintenance teams, production facilities and service contractors requiring a larger quantity of thermal fluid for system filling, scheduled oil changes, top-up stock or ongoing plant maintenance. It is particularly suitable for customers operating thermal oil heaters, heat exchangers, temperature control units, mould heating systems, industrial ovens, process heating equipment and closed thermal oil circuits where a mineral-based 25 cSt heat transfer oil is specified.

Marvell Heat Transfer Oil 25 is designed for indirect heating systems where the thermal fluid transfers heat from the heater to process equipment without direct contact between the heat source and the material being heated. In these systems, the oil must circulate efficiently through pumps, pipework, heating coils, heat exchangers and process equipment while resisting oxidation and thermal degradation. The light viscosity of approximately 25 cSt at 40°C helps support good start-up circulation, efficient heat transfer and reduced pumping resistance compared with heavier thermal oils.

Thermal fluid performance is highly dependent on system design, operating temperature, circulation rate, expansion tank arrangement, exposure to air and maintenance practices. Marvell Heat Transfer Oil 25 is formulated to resist thermal cracking when used within recommended operating conditions. Thermal cracking can cause oil breakdown, reduced flash point, increased volatility, carbon formation and deposit build-up. A thermally stable oil helps maintain system efficiency and reduces the risk of deposits that can interfere with heat transfer and cause localised hot spots.

The product also provides good resistance to chemical oxidation. Oxidation is one of the main causes of thermal oil deterioration, particularly where oil is exposed to oxygen, excessive heat or contamination. Oxidation can increase acidity, viscosity, sludge and varnish formation. Marvell Heat Transfer Oil 25 uses highly refined mineral base oil technology to help resist these changes and support long service life when the system is properly designed, operated and monitored.

Efficient heat transfer is important in many industrial processes because poor thermal fluid condition can increase energy use, slow production, reduce temperature accuracy and create maintenance issues. Marvell Heat Transfer Oil 25 offers good specific heat and thermal conductivity characteristics, helping the fluid transfer heat effectively through the system. Its low viscosity also supports rapid heat movement and good circulation, particularly during start-up and operation.

This product may be used in closed indirect heating systems and selected open or cold-oil-sealed systems where the operating temperature and system design are suitable. In closed systems, the product may be used up to approximately 300°C where the equipment manufacturer and system design allow. In open systems, operating temperature is generally more limited, with guidance up to approximately 120°C due to increased oxidation and fuming risk when oil is exposed to air. The typical maximum fluid temperature should always be confirmed against the system manufacturer’s recommendations.

Marvell Heat Transfer Oil 25 200L is not an engine oil, hydraulic oil, compressor oil, gear oil, transmission fluid or coolant. It should only be used in compatible heat transfer systems designed for mineral-based thermal oils. For best performance, the system should be clean, dry and free from water, sludge, process contamination and incompatible fluids before filling.

Specifications, Standards and Performance Requirements

Marvell Heat Transfer Oil 25 is designed for industrial thermal oil systems requiring a light mineral-based heat transfer fluid with high thermal stability, oxidation resistance and efficient circulation characteristics.

Product Type: Heat Transfer Oil
Common Description: Thermal Fluid
Pack Size: 200 Litre
Viscosity Grade: ISO 25 type thermal oil
Base Oil Type: Highly refined mineral oil
Application: Closed indirect heating systems and selected open systems
Primary Function: Heat transfer, thermal stability and system circulation
Operating System Type: Closed thermal oil circuits, indirect heating systems and selected cooling circuits
Recommended Use: Industrial heat transfer applications requiring a 25 cSt thermal fluid
Ready to Use: Yes
Dilution Required: No

Typical temperature guidance:

Closed Systems: Up to approximately 300°C where system design, operation and manufacturer recommendations allow
Open Systems: Up to approximately 120°C where fuming, oxidation and air exposure are controlled
Typical Maximum Fluid Temperature: Approximately 250°C depending on operating conditions and system design

Always confirm the required thermal fluid type, viscosity, operating temperature range and system compatibility with the equipment manufacturer before use.

Key Features and Benefits

Marvell Heat Transfer Oil 25 provides efficient heat transfer performance for suitable industrial thermal oil systems. Its light viscosity assists circulation through pumps, pipework, heaters and heat exchangers, helping the system reach operating temperature efficiently. Good circulation helps reduce the risk of localised overheating and supports more consistent process temperature control.

The product offers strong resistance to thermal cracking under recommended operating conditions. Thermal cracking can reduce fluid life and contribute to deposits, carbon formation and flash point reduction. A stable thermal fluid helps maintain safer and more reliable operation over extended service periods.

Marvell Heat Transfer Oil 25 also provides good oxidation stability. In thermal oil systems, oxidation can create acidity, sludge, varnish and viscosity change, all of which can reduce heat transfer efficiency and increase maintenance requirements. The use of highly refined base stocks helps resist oxidation and supports longer oil life when the system is correctly maintained.

The low vapour pressure and stable flash point characteristics make this product suitable for industrial heat transfer systems where controlled volatility and stable operation are required. Its non-corrosive nature under normal operating conditions helps protect internal system surfaces, piping, pumps and heat transfer components.

The 200L drum format is ideal for users who need larger quantities for system fills, equipment servicing, plant maintenance or regular top-ups. It reduces the need for multiple small containers and is suitable for workshops, manufacturing plants and industrial sites that manage thermal fluid inventory as part of routine maintenance.

Applications

Marvell Heat Transfer Oil 25 200L is suitable for industrial heat transfer systems where a light mineral thermal fluid is required. Typical applications include:

Closed indirect heating systems
Thermal oil circulation systems
Industrial process heating equipment
Heat exchangers
Temperature control units
Mould heating systems
Industrial ovens and heating circuits
Chemical and manufacturing process heating
Selected open systems operating within suitable temperature limits
Cold-oil-sealed systems where compatible
Indirect heating and cooling systems
Thermal oil heaters
Production plant heating circuits
Maintenance top-up for compatible heat transfer systems
System filling and scheduled thermal oil replacement

This product should not be used as an engine oil, hydraulic oil, gear oil, compressor oil, automatic transmission fluid, brake fluid or water-based coolant.

Typical Physical Properties

Handling & Storage Advice

Store Marvell Heat Transfer Oil 25 200L in a clean, dry and well-ventilated area away from direct sunlight, rain, moisture, dust and contamination. Keep the drum sealed when not in use to prevent water, dirt, process material or foreign particles from entering the oil. Contamination can reduce thermal fluid performance and may contribute to sludge, deposits, corrosion or reduced system efficiency.

Store drums upright with bungs tightly closed. If stored outside, drums should be protected from rain and weather exposure to prevent water collecting around the drum openings. Water contamination in thermal oil systems should be avoided because it can cause foaming, pressure instability, corrosion and operational issues during heating.

Use only clean pumps, hoses, funnels and transfer equipment when dispensing the product. Do not use equipment that has previously been used for coolant, water, solvents, fuel, waste oil or incompatible chemicals unless it has been properly cleaned. Even small quantities of incompatible fluid or water can affect heat transfer oil stability and service life.

Before filling or topping up a thermal oil system, confirm that the existing fluid is compatible and that the system requires a 25 cSt mineral-based heat transfer oil. Mixing different thermal fluids without confirming compatibility may affect viscosity, oxidation resistance, flash point and deposit control. When changing from another thermal fluid, drain the system as completely as practical and follow the equipment manufacturer’s flushing or changeover procedure.

Avoid prolonged exposure of the oil to excessive heat during storage. Although the product has a high flash point, normal lubricant storage and industrial chemical handling precautions should be followed. Keep away from ignition sources, open flames and unnecessary heat exposure.

Used heat transfer oil should be collected and disposed of through an authorised waste oil collection service. Do not discharge used oil into drains, soil, waterways or general waste. Follow workplace safety and environmental requirements for drum handling, spill control, storage and disposal.

Directions for Use

Before using Marvell Heat Transfer Oil 25, check the thermal system manual or manufacturer’s recommendation to confirm that a mineral-based heat transfer oil with approximately 25 cSt viscosity at 40°C is required. Inspect the system for leaks, blocked strainers, degraded seals, sludge, water contamination or signs of previous overheating before filling.

For new systems, ensure the circuit is clean and dry before charging with thermal fluid. Water should be removed before commissioning because trapped water can cause foaming, pressure surges and unstable operation as temperature increases. Fill the system according to the equipment manufacturer’s procedure and allow suitable expansion space.

For existing systems, drain degraded or contaminated fluid while following safe shutdown and cooling procedures. Inspect the drained oil for dark colour, burnt odour, sludge, acidity, carbon deposits, abnormal viscosity change or reduced flash point. These signs may indicate overheating, oxidation, contamination or extended service beyond the recommended oil condition.

After filling, circulate the oil and gradually bring the system up to operating temperature in accordance with the system procedure. Avoid rapid overheating of cold oil and avoid operating above the recommended temperature limits. Check for leaks, abnormal pump noise, flow restrictions and pressure changes during commissioning.

Regular oil monitoring is recommended for thermal systems. Important properties to check include viscosity, acidity, flash point, insoluble content and signs of contamination. Changes in the oil’s physical characteristics are often more important than a single test value, so trending oil analysis over time is useful for determining service life and replacement timing.

Important Warnings

Marvell Heat Transfer Oil 25 should only be used in systems designed for mineral-based thermal fluids. Do not use this product in automotive engines, hydraulic systems, gearboxes, automatic transmissions, brake systems or water-based cooling systems. It must not be mixed with water, glycol coolant or incompatible fluids.

Do not operate a thermal oil system above the recommended temperature range. Excessive temperature can accelerate oxidation, thermal cracking, deposit formation and flash point reduction. Localised hot spots, restricted circulation, blocked filters, poor system design or undersized heaters can also shorten oil life and create operational risk.

Do not mix with other heat transfer fluids unless compatibility has been confirmed. Different base oils or additive systems may not be compatible and may affect thermal stability, deposit control and service life. If uncertain, drain and flush the system before refilling.

Avoid contact with hot oil. Hot thermal fluid can cause serious burns. Wear suitable personal protective equipment when handling drums, transferring fluid, draining systems or performing maintenance. Allow equipment to cool safely before opening any part of the system.

Suitable Customers and Industries

Marvell Heat Transfer Oil 25 200L is suitable for industrial maintenance teams, manufacturing plants, process heating operators, plastics and moulding businesses, chemical processing facilities, packaging plants, workshops, service contractors and general industrial users requiring a light mineral-based thermal fluid.

The 200L drum is particularly suitable for customers operating larger or multiple thermal oil systems where 20L containers are not practical. It is also suitable for planned maintenance, system commissioning, scheduled oil replacement and bulk top-up requirements.

For manufacturing and industrial users, this product provides a practical balance of thermal stability, fluidity and efficient heat transfer performance. For maintenance teams, the 200L format provides a cost-effective and convenient option for keeping sufficient thermal fluid available on site.