A magnetic drive pump is a type of centrifugal pump that uses magnetic coupling (magnetic transmission) to transmit torque, thereby achieving complete static sealing.

Product Attributes: Maximum Head: >150 m; Maximum Flow Rate: >400 L/min; Drive Type: Electric Motor; Number of Impeller Stages: Single-Stage Pump; Impeller Suction Configuration: Single-Suction Pump; Pump Shaft Orientation: Vertical Pump; Transport Packaging: Wooden Crate; Standards: API 685; Brand: Dalian Tianhe Pump Industry Co., Ltd.; Country of Origin: Dalian, Liaoning Province, China.

The technical parameter system for magnetic drive pumps is closely linked to the design standards they adhere to. Depending on your application scenario, this system can be broadly categorized into two types: international overpressure standards (API 685) and national/industry standards (such as JB/T 7742). The former is suitable for harsh operating conditions in industries like petrochemicals, while the latter is used in general industrial applications.

1. API 685 Heavy-Duty Magnetic Drive Pumps (Petrochemical/Oil and Gas Industry)
This is the leak-free version of the API 610 pump that you have previously focused on, designed for high-risk and highly volatile process fluids. Both leading international brands (such as Flowserve) and major domestic manufacturers (such as Wanfulong) have already launched mature product lines in this category. The following are typical parameter ranges based on the API 685 standard:

Supplementary Notes on the Typical Range of Parameter Items/Design Capacity
Typical applications with a flow range of 1.5 to 1,400 cubic meters per hour, compliant with API 685 standards.
The lifting capacity ranges from 10 to 125 meters (and can be even greater); a single-stage lift provides this capacity, while multi-stage cascading can achieve even higher levels.
The maximum working pressure is 10.0 MPa (approximately 100 bar), with pressure ratings typically available at 2.5 MPa, 4.0 MPa, and 10.0 MPa.
Suitable for a temperature range of -80°C to +450°C, both the low-temperature and high-temperature models offer broad applicability.
The typical speeds of 4-pole and 2-pole motors are 1,450 and 2,900 rpm, respectively.
The motor power range is broad, spanning from 1.1 to 250 kilowatts, thereby meeting the requirements of various operating conditions.
Applicable media: alcohols, benzene, phenols, acids, alkalis, liquid chlorine, hydrocarbons, and more. Suitable for flammable, explosive, highly toxic, and corrosive liquids.
The core design standard API 685 (equivalent to API 685-2000) specifies the minimum requirements for sealless pumps, including mandatory provisions such as secondary containment and internal circulation.
Material grades 304, 316, 316L, HC276, and other optional corrosion-resistant alloys all comply with the material requirements of API 685.
Key Technical Features
Leak-free design: A alloy isolation sleeve (such as Hastelloy C4) is used as the static sealing barrier, effectively eliminating leakage at the structural level.

Secondary Sealing: According to API 685, a secondary safety system (outer casing plus backup seal rings) must be designed to provide additional protection in the event of primary barrier failure.

Internal flushing and cooling: The process fluid is circulated internally through the equipment to lubricate the bearings and cool the magnetic coupling, eliminating the need for an external flushing system.

2. National/Industry Standards for Magnetic Drive Pumps (General Industrial Applications)
This type of pump complies with domestic standards such as JB/T 7742 and JB/TQ 786 and is widely used in industries including chemical processing, pharmaceuticals, electroplating, and environmental protection. Depending on the specific series and material, its performance parameters are tailored to meet particular application requirements.

1. CQB Series/IMC Series (Standard Type, Temperature Resistance ≤100°C)
This is the most common series of stainless steel magnetic drive pumps, offering broad parameter versatility.

Supplementary Notes on the Typical Range of Parameter Items/Design Capacity
Depending on the specific model, the flow rate can reach approximately 50 cubic meters per hour, with some series capable of even higher flow rates.
The elevator can reach approximately 50 meters.
Maximum working pressure ≤ 1.6 MPa, standard design pressure
Suitable for a temperature range of -20°C to +100°C; fluoroplastic lining provides even higher temperature resistance.
Medium density ≤ 1600 kg/m³. If the density is too high, a motor with higher power should be selected.
Medium viscosity ≤ 30 × 10⁻⁶ m²/s, which is approximately 30 cSt.
The core standard JB/T 7742 (Small Magnetic-Drive Centrifugal Pumps) specifies the basic parameters and technical requirements.
2. CQG Series/IMC-G Series (High-Temperature Type, Temperature Resistance ≤280–350°C)
Specifically designed for high-temperature media such as heat-transfer oil and thermal fluids.

Supplementary Notes on the Typical Range of Parameter Items/Design Capacity
Suitable for temperatures ranging from ≤280°C to 350°C, featuring special heat-resistant materials and a cooling structure.
Working pressure ≤ 1.6 MPa
The flow rate ranges from approximately 1 to 100 cubic meters per hour, meeting the requirements for conveying common high-temperature media.
Increase by approximately 10 to 50 meters
The core design features a bearing housing with a cooling cavity, which uses circulating water or fans to isolate high temperatures and thereby protect the bearings and magnets.
3. Key Limitations and Taboos in Selection
Regardless of the type of magnetic drive pump used, the following common limitations must be observed during operation; failure to do so can easily result in damage:

Absolutely no dry running: The bearings and cooling/lubrication of a magnetic drive pump rely entirely on the conveyed fluid; even a few seconds of dry running can result in burnout.

Media cleanliness: The presence of ferromagnetic particles is strictly prohibited (a magnetic filter must be installed). If the media contains hard particles, a strainer must be installed at the inlet.

Media prone to crystallization/polymerization: When conveying media that are likely to precipitate or crystallize (such as certain chemicals), the pump must be promptly cleaned after shutdown to prevent the medium from solidifying and jamming the rotor.

Abstract
Application Level Core Standard Temperature Range Pressure Limit Main Application Areas
Heavy-duty API 685—operating range: 80°C to 450°C, pressure rating: 10.0 MPa (100 bar)—is suitable for the refining, petrochemical, liquefied natural gas, and high-hazard chemical industries.
General-purpose JB/T 7742, −20°C to 100°C, 1.6 MPa; used in fine chemicals, pharmaceuticals, electroplating, and environmental protection.
The high-temperature enterprise standard refers to a thermal oil furnace with an API rating of ≤280–350°C and a pressure rating of 1.6 MPa, used for the conveyance of heat transfer media.
What type of application scenario are you currently focusing on? If you require further confirmation of the selection recommendations for a specific operating condition, please provide the specific requirements for the process fluid, temperature, flow rate, and head, and I will assist you in making a more accurate assessment.

Revolutionary functionality: This design employs the magnetic force generated by a set of permanent magnets (or electromagnets) to non-contactly penetrate the isolation sleeve and transmit the motor’s torque to the impeller mounted on the pump shaft. By completely eliminating the conventional dynamic seals on the pump shaft—whether packing seals or mechanical seals—this innovative approach structurally eliminates the possibility of leakage.

Design Standards:

Industrial grade: API 685, “Non-Scented Centrifugal Pumps for the Petroleum, Petrochemical, and Natural Gas Industries,” represents the highest standard and imposes extremely stringent requirements for reliability and safety.

General industrial grade: ASME B73.3M is the most widely used standard for magnetic drive pumps in the chemical industry.

ISO 2858/ISO 5199: Internationally recognized standards.

2. Detailed Description of the Structure and Operating Principle
The core of a magnetic drive pump lies in “magnetic transmission” and “passive lubrication and cooling circulation.”
Functional description of key components:

Magnetic Coupler:

External magnetic cylinder: connected to the motor shaft, typically incorporating a low-temperature-resistant yet highly magnetic rare-earth permanent magnet (such as neodymium–iron–boron NdFeB) or a samarium–cobalt SmCo magnet with excellent high-temperature resistance.

Built-in magnetic cylinder: connected to the pump shaft, it also contains a permanent magnet ring and is enclosed by an isolation sleeve.

Operating principle: The motor drives the outer magnetic rotor to rotate, and its magnetic field passes through the air gap and the isolation sleeve to drive the inner magnetic rotor to rotate in synchrony, thereby achieving non-contact torque transmission.

Isolation Sleeve: This is the pump’s core static sealing barrier, typically fabricated from high-resistivity, corrosion-resistant metals such as Hastelloy or titanium, or from ceramics. It must be thin enough to minimize eddy-current losses, yet robust enough to withstand system pressure.

Bearing System:

Location: The pump end is equipped with two sets of sliding bearings, located on the impeller side (front bearing) and the internal magnetic cylinder side (rear bearing), respectively.

Material: The lubricating action of the conveyed medium is essential; silicon carbide (SiC) is typically used. According to API standards, SiC is recommended as the preferred material due to its extremely high hardness, outstanding wear resistance, and excellent self-lubricating properties. Other suitable materials include carbon graphite and cemented carbides.

Circulation and Cooling System:

Internal circulation: A small fraction of the process fluid—approximately 1% to 5% of the total flow—is drawn from the pump’s high-pressure zone, passes through the rear bearing, the rotor chamber (which serves to cool the internal magnetic cylinder and the isolation sleeve), and the front bearing, and is then returned to the pump’s low-pressure suction inlet. This circulation lubricates the bearings, cools the permanent magnets, and provides an isolating function for the isolation sleeve.

External Cooling: For high-temperature, easily vaporizable, or poorly lubricated fluids, it is generally necessary to install a cooling jacket on the outside of the isolation sleeve or pump cover and circulate cooling water through the jacket to enhance heat dissipation and prevent the fluid from vaporizing within the rotor cavity.

3. Core Advantages
100% Leak-Free: Featuring a static sealing design that fundamentally eliminates leakage of toxic, hazardous, flammable, explosive, and high-cost process fluids, ensuring safety and environmental protection.

Easy maintenance: No need to maintain or replace the mechanical seal, eliminating the need for complex alignment procedures. For canned motors pumps, replacement of wear-prone components such as bearings is relatively straightforward and can usually be performed on-site.

High reliability: the transmission components have a relatively simple structure and exhibit no mechanical wear (magnetic drive is non-contact).

Overload Protection: When the pump end experiences overload or jamming, the inner and outer magnetic couplings will slip, thereby protecting the motor from burnout.

Modular design: Typically features a pull-out configuration, eliminating the need to disconnect piping when servicing internal components.

4. Main Drawbacks and Limitations