In industrial fluid conveyance sectors including chemical, petroleum, pharmaceutical and electroplating industries, standard magnetic pumps deliver leak-free transportation via magnetic coupling and are suitable for conventional liquid media at ambient temperature. However, when handling temperature-sensitive, physically unstable and high-risk special media, they are prone to problems such as pump chamber clogging, medium deterioration, leakage and contamination, as well as equipment damage.

As an improved special type of magnetic pump, the jacketed magnetic pump is fitted with full jacket structures across the pump body and cover. Steam, thermal oil, hot water or refrigerant can be circulated inside to realize constant temperature control. It combines the zero-leakage advantage of magnetic pumps with constant-temperature control performance, serving as a dedicated conveying device that cannot be replaced by ordinary magnetic pumps for ambient-temperature service. Based on medium properties and operational challenges, this article comprehensively classifies media that mandatorily require jacketed magnetic pumps for transportation, helping enterprises select equipment accurately and avoid operational failures.

I. Low-temperature Solidifiable Media with High Viscosity at Ambient Temperature

Such media have a freezing point higher than the ambient temperature. Their fluidity drops sharply as temperature decreases, easily adhering to the pump inner wall, blocking flow passages and even solidifying to lock the impeller. Standard magnetic pumps fail to convey these media, so jacketed magnetic pumps are essential to heat and maintain fluidity. They are the most widely applied type for temperature-controlled pumping in industrial scenarios.

1. Petrochemical Media: Heavy Oil, Asphalt and Paraffin

Petrochemical by-products such as road asphalt, vacuum residue, industrial paraffin and coal tar are solid or pasty at room temperature with viscosity up to tens of thousands of mPa·s. They can only be pumped normally within the temperature range of 50-120°C. The jacketed magnetic pump adopts low-pressure steam circulating through the jacket for constant-temperature heating to stabilize medium viscosity, ideal for asphalt mixing, heavy oil transfer and paraffin melting production lines. Meanwhile, its seal-free magnetic structure eliminates risks of heavy oil leakage and oil gas emission, making it applicable for flammable and explosive petrochemical working conditions.

2. Industrial Hot-melt Lubricating Grease

Industrial hydrogenated oil, hot-melt lubricants and special anti-freeze grease will stratify and solidify with drastically increased viscosity when the ambient temperature falls below 25°C, blocking pipeline transportation and disrupting oil supply for production lines. The jacketed magnetic pump maintains a precise temperature of 40-60°C to keep grease in a homogeneous liquid state. It is extensively used in heavy industry lubrication, mechanical maintenance and industrial grease batching lines to ensure stable grease delivery.

3. Polymer Hot-melt Slurries

Hot melt adhesives, resin slurries and rubber softeners are solid at room temperature and pumpable only at elevated temperatures. The jacketed magnetic pump maintains stable process temperature to prevent semi-solidification and caking of materials, ensuring continuous material feeding for coating, rubber and plastic processing procedures.

II. Chemical Media Prone to Crystallization and Scaling under Temperature Fluctuations

A large number of inorganic salt and fine chemical solutions will precipitate crystal particles when temperature drops. Crystals can abrade the pump body, block pipeline filters and even rupture the magnetic isolation sleeve, greatly shortening pump service life. Jacketed magnetic pumps keep the medium temperature above the critical crystallization point to fundamentally prevent crystal precipitation, supporting continuous chemical production.

1. Molten Inorganic Salts and Saturated Solutions

Urea melt, ammonium sulfate solution, calcium chloride anti-freeze solution and sodium sulfate saturated solution used in the fertilizer industry feature a narrow crystallization temperature range and rapid crystal formation. Particularly for urea melting processes, slight temperature drop will immediately trigger crystallization. Special high-temperature jacketed magnetic pumps maintain a constant temperature of 130-140°C to ensure stable delivery of molten urea, matching the technical requirements of fertilizer synthesis and tail gas treatment.

2. Crystallizable Liquid Chemicals for Fine Chemicals

Dye stock solutions, electroplating brighteners, photographic color developing solutions and concentrated water treatment flocculants may suffer concentration deviation once microcrystals separate out, compromising product quality. With precise constant temperature control, the jacketed magnetic pump prevents crystallization. Equipped with PTFE-lined anti-corrosion structure, it adapts to weakly acidic and alkaline crystallizable media and is widely deployed in workshops for electroplating, photosensitive materials and water treatment chemicals.

III. Temperature-sensitive Pharmaceutical Media Requiring Constant Temperature for Quality Preservation

Media in the pharmaceutical industry are subject to strict hygiene standards. Temperature fluctuation may cause material denaturation, efficacy loss and excessive microbial growth. Overheating or low-temperature solidification is prohibited. Jacketed magnetic pumps deliver precise constant temperature control, and feature dead-space-free design, easy sanitization and zero medium leakage, complying with GMP standards for clean pharmaceutical production.

Constant-temperature Pharmaceutical Stock Solutions

Traditional Chinese medicine extracts, constant-temperature fermentation broths, sterile medicinal liquids and mixed medicinal glycerol solutions may lose active ingredients and breed bacteria due to temperature changes. The full-jacketed magnetic pump avoids contamination from mechanical seal debris and enables closed-loop constant-temperature transportation. It is suitable for pharmaceutical batching, liquid transfer and purification processes, eliminating cross-contamination of media.

IV. High-temperature, High-risk, Volatile and Corrosive Media

Certain chemical media need to be kept at high temperatures to retain chemical activity, and are characterized by corrosiveness, toxicity, flammability, explosiveness and volatility. Ordinary high-temperature centrifugal pumps carry risks of shaft seal leakage, while standard magnetic pumps without jacket structures will face alternating gasification and liquefaction of cooled media, resulting in cavitation and dry running. Integral jacketed magnetic pumps combine jacket temperature control, anti-corrosion and zero-leakage performance, which are specially designed for such high-risk media.

1. High-temperature Corrosive Chemical Solvents

High-temperature dilute acid, molten halides, high-temperature organic additives and discharge solvents from synthesis reactors work at temperatures up to 280-300°C with strong corrosivity. PTFE-lined and stainless steel jacketed magnetic pumps withstand high-temperature corrosion, maintain the chemical activity of media, and prevent medium stratification and aggravated corrosion after temperature drop. They are applied in fine synthesis and organic chemical reaction sections.

2. Volatile and Toxic High-risk Media

High-temperature benzene-based additives, toxic fragrance intermediates and volatile curing agents tend to vaporize and release harmful fumes when cooled, polluting the workshop and bringing explosion hazards. The jacketed magnetic pump realizes hermetic constant-temperature transportation to suppress medium volatilization. Its leak-free magnetic structure prevents discharge of toxic substances, suitable for transferring high-risk materials in explosion-proof chemical workshops.

V. Low-temperature Refrigerated Media to Prevent Gasification

Different from heating service, some low-temperature media require refrigerant circulation for cooling and temperature control, so as to avoid medium gasification and pressure surge caused by ambient temperature rise. Full jacketed magnetic pumps (with refrigerant circulated reversibly for cooling) are adopted for such low-temperature refrigeration conditions as dedicated pumps for special low-temperature conveyance.

Typical media include liquid ammonia, liquid carbon dioxide, low-temperature electroplating solutions and low-temperature extraction solvents. Continuous cooling via the pump jacket stops medium gasification and pump cavitation, maintaining stable liquid transportation. These pumps are applied in cold-chain chemical processes, low-temperature extraction and low-temperature electroplating procedures.

Supplementary Notes: Media Not Requiring Jacketed Magnetic Pumps

For media with stable fluidity at ambient temperature, no crystallization or solidification, and properties unaffected by temperature, such as clean water, conventional dilute acid and alkali, normal-temperature solvents and regular oils, standard magnetic pumps are fully applicable without additional jacket structures, which cuts down equipment procurement and operation & maintenance costs.

Jacketed magnetic pumps are mandatory only when the medium meets any of the following criteria: freezing point higher than ambient temperature, tendency to crystallize, need for constant temperature to preserve quality, high-temperature anti-gasification requirement or low-temperature anti-boiling requirement.

Core Application & Advantages of Jacketed Magnetic Pumps

Jacketed magnetic pumps are mainly used for four categories of media: high-viscosity media prone to solidification at ambient temperature, chemical media easy to crystallize under temperature change, temperature-sensitive pharmaceutical media for quality preservation, as well as high/low-temperature high-risk volatile special media.

Beyond heating thermal control, they deliver five core strengths: low-temperature refrigeration, stable medium properties, anti-clogging performance, zero leakage, and adaptability to explosion-proof and clean working conditions. When selecting pumps, enterprises can quickly determine the necessity of jacketed magnetic pumps by checking the medium’s freezing point, crystallization temperature and process constant-temperature requirements.