Regarding the explosion protection of motors, how do people decide on the materials to be used for coupling guards, mechanical seal gland covers, etc.?

Whether a motor is explosion-proof is generally determined based on the operating environment. The protective covers for couplings are usually of the type that prevents sparks; in the absence of special requirements, the default settings provided by the supplier are used. I use 304 stainless steel for the gland seals.

Whether a motor is explosion-proof is generally determined based on the operating environment. When selecting a motor, whether to choose an explosion-proof type, an intrinsically safe type, or another type, which standards are used for making that decision? Coupling guards are usually of the spark-proof type; unless there are special requirements, the supplier’s default design is used. What are the different types of spark-proof guards, and what are the considerations when choosing them compared to non-spark-proof guards? I use 304 stainless steel for the machine seal gland covers. Are there any other explosion-proof materials?

Haha, first of all, we are the supplier. The type of motor to be chosen is generally determined by the customer; I’m not aware of the specific criteria used. There is a standard for coupling guards: GB8196-2003. Generally, the guards are made of all aluminum or all copper (while the couplings are made of steel); it is sufficient that no sparks are generated when the guard comes into contact with the coupling. Is it required that the machine seal gland be explosion-proof?

The materials used in explosion-proof motors are basically fixed; they consist of copper and steel. The coupling guards are made of carbon steel, as strength is important and proper fixation is necessary. The machine seal gland is made of stainless steel

Where is the standard? Which standard is it? How can standards be integrated with the field and translated into practical applications on site?

GB3836.1-2010 specifies the general requirements for explosive-proof environmental equipment; it provides details on the materials to be used for motor explosion protection, as well as requirements for testing strength； Those that are sealed have corresponding standards

New technologies for mechanical seals that utilize new materials and processes are advancing rapidly at present, and the following are such new technologies for mechanical seals. The grooved sealing technology for sealing surfaces has seen the creation of various flow channels on the sealing surfaces of mechanical seals in recent years, in order to generate hydrostatic and dynamic pressure effects; this technology is still evolving continuously. In the past, zero-leakage sealing technology held the view that both contact and non-contact mechanical seals could not achieve zero leakage (or no leakage). Israel has utilized grooved sealing technology to introduce a new concept of zero-leakage, contactless mechanical face sealing, which has been applied in lubrication pump systems for nuclear power plants. Dry-running gas seal technology is a type of seal that applies slotted seal technology to gas sealing. The upstream pumping sealing technology utilizes flow channels on the sealing surface to pump a small amount of leaked fluid from the downstream back to the upstream.

　　The casings of both ordinary motors and explosion-proof motors are cast from pig iron, followed by further precision machining to fit with the stator core. However, due to the special operating conditions of explosion-proof motors, better electrical sealing is provided; even if the wiring components inside the motor are damaged by fire, it will not cause flammable gases in the surrounding environment to catch fire. Ordinary motor casings do not have such explosion-proof isolation capabilities, and the motor’s output wires lack any special sealing measures. 　　Motor casing The manufacturing of the motor casing is a very important step in motor production. The materials for motor casings generally include cast iron, cast aluminum alloys, section steel (steel pipes), steel plates, etc. Domestically, small-power motors generally use cast iron, cast aluminum alloys, or steel (steel tube) casings. The amount of work required for processing these motors is large, there are many processing steps, and the production cycle is long. The working environment for operators is poor, and the labor intensity is high. There is also significant waste of energy and materials. 　　Internationally, developed countries such as Germany, France, and Japan had already begun to use steel frames on a large scale by the middle of this century. This new casing processing technique is a minimally machining process. Some domestic motor manufacturers began researching the production of steel plate enclosures in the early 1970s, and production on a certain scale was established by the mid-1980s. However, since the process involves cutting with a shear machine – forming a “U” shape (or a “W” shape) – then forming an “O” shape, welding (manual or carbon dioxide shielded welding) – polishing – turning – and finally shaping the eight pieces (referring to chassis without feet), there are many different types of equipment used, and human factors have a significant impact on quality, making it difficult to ensure consistency in quality. 　　In the manufacturing of steel plate enclosures, some developed countries currently use advanced specialized processing equipment for such tasks; the level of mechanization and automation is very high, resulting in high-quality products. Small-power motors available in the advanced **motor market are now generally motor units with steel casing. In 1989, China began to develop individual machines for temple processing using steel plate enclosures – such as steel plate enclosure rolling machines and motor steel plate enclosure welding machines. In recent years, material prices have been high, and the domestic motor market has been weak. To reduce the manufacturing costs of motors, improve the quality of steel plate casings, and enable China’s low-power motors to enter the motor markets of developed countries and gain a foothold in those markets, it is necessary to conduct research on new manufacturing processes for motor steel plate casings.

In the manufacturing of steel plate enclosures, some developed countries currently use advanced specialized processing equipment for such tasks; the level of mechanization and automation is very high, resulting in high-quality products. Small-power motors available in the advanced **motor market are now generally motor units with steel casing. In 1989, China began to develop individual machines for temple processing using steel plate enclosures – such as steel plate enclosure rolling machines and motor steel plate enclosure welding machines. In recent years, material prices have been high, and the domestic motor market has been weak. To reduce the manufacturing costs of motors, improve the quality of steel plate casings, and enable China’s low-power motors to enter the motor markets of developed countries and gain a foothold in those markets, it is necessary to conduct research on new manufacturing processes for motor steel plate casings.

May I use stainless steel for the coupling cover? If not, how can it be proven that stainless steel is a sparking material?

The general protective cover is made of all-aluminum/all-copper or A3 material (the coupling is steel)