Jiangsu Haifa Machinery Manufacturing Co., Ltd.

Abstract: With the development of the petrochemical, coal chemical, new energy, and fine chemical industries, high-temperature, flammable, explosive, and toxic media have imposed higher requirements on the safety of conveying equipment. Traditional centrifugal pumps adopt mechanical seal structures, which suffer from issues such as wear, leakage, and high maintenance costs during long-term operation. Magnetic drive pumps transmit power through the coupling of inner and outer magnetic rotors, enabling operation without mechanical shaft seals and significantly reducing the risk of medium leakage. on the API 685 sealless magnetic drive pump design concept, Jiangsu Haifa Machinery Manufacturing Co., Ltd. has developed a solution for high-temperature hazardous medium conditions, employing a "double-layer protection structure + leakage detection probe + containment shell RTD temperature monitoring" system to enhance the operational safety of high-temperature magnetic drive pumps and online equipment status monitoring.

I. Risk Analysis of High-T Magnetic Drive Pump OperationDuring the operation of magnetic drive pumps, the containment shell not only serves to isolate the medium but is also a critical component of magnetic transmission. Under high-temperature and high-speed conditions, the following risks may exist: temperature rise caused by magnetic eddy current losses in the containment shell local overheating due to insufficient cooling circulation; reduced containment shell strength from long-term corrosion; and medium leakage under abnormal conditions. Therefore, high-safety-grade magnetic drive pumps require addition of an active monitoring and protection system.

II Double-Layer Protection Leakage Detection DesignJiangsu Haifa high-temperature magnetic drive pumps a double-layer protection:
First layer: Containment Shell — isolates the medium under normal operating conditions.
Second layer: Containment Chamber — medium and detects leakage in the event of containment shell abnormalities.
A leakage protection probe is configured: when the containment shell experiences corrosion perforation, cracking, or seal failure, and the medium enters the secondary containment area, the probe immediately detects the condition and sends an alarm signal to the/DCS system, achieving: leakage alarm → interlock shutdown → prevention of accident escalation.

III. Containment Shell RTD Temperature Monitoring Technology
Targeting the operating characteristics of high-temperature magnetic pumps, a Pt100 RTD temperature sensor is installed in the containment shell area for real-time monitoring of: containment shell temperature; thermal status of the magnetic transmission area; and abnormal operating trends.
Protection logic:
Containment shell temperature rise
↓
RTD detection
↓
PLC/DCS alarm
↓High-temperature interlock
Through online temperature monitoring the following can be effectively prevented: dry running; insufficient cooling; demagnetization of magnetic steel; and internal pump damage.

IV. Main Technical Features of High-Temperature Magnetic Drive Pumps
Item | Design Feature | Executive Standard
API 685
Structure | Magnetic drive sealless structure
temperature | -100°C to 450°C
Applicable media | Flammable, explosive, toxic, high-temperature chemical mediaLeakage protection | Double-layer containment chamber + leakage detection probe
Temperature monitoring | Containment shell Pt100 RTD
Control method | PLC/DCS online monitoring
Material selection | 316L, 2205, 2507, 904L, Hastelloy, etc.

. Technical Advantages of Jiangsuifa High-Temperature Drive Pumps
Jiang Haifa Machinery Manufacturing Co., Ltd. has long been focused on: API 610 petrochemical pumps; API 685 magnetic drive pumps; pumps for high-temperature,-pressure, and highly corrosive media; and custom design for non-standard operating conditions. Through the combination of: mechanical-seal-free magnetic drive technology + double-layer protection leakage detection technology + containment shell RTD temperature monitoring technology, the company provides safe and zero-leakage conveying solutions for the petrochemical, new energy, coal chemical, and special industrial sectors.

Reference Standards
API 685 — Centrifugal Pumps for Petroleum, Petrochemical and Natural Gas Industries — Seal-less Pumps
API  — Centrifugalumps for Petroleum, Petrochemical and Natural Gas Industries
15783 — Seal-less Pumps — II

FAQ — Frequently Asked Questions
Q1: Why do magnetic drive pumps still require leakage protection?
Magnetic drive pumps eliminate the mechanical shaft seal, but the shell remains part of the pressure boundary The double-layer protection and probe provide a second line of safety protection in the event of containment shell abnormalities.
Q2: What is the function of RTD installed on the containment shell?
The RTD used to monitor the containment shell temperature in real time promptly detecting abnormal temperature rises to prevent demagnetization of magnetic steel, dry, and equipment damage.