Abstract: The present disclosure discloses a sintered neodymium-iron-boron magnet and a preparation method thereof. The sintered neodymium-iron-boron magnet includes the following raw materials in mass percentage: 1%-40% of an iron powder or a steel powder with a magnetic induction intensity of more than 1.2 T, not more than 10% of a praseodymium-neodymium metal hydride powder, and a remainder of a neodymium-iron-boron fine powder, wherein the mass percentages of the above raw materials add up to 100%. The preparation method includes: weighing the raw materials in mass percentage; mixing the weighed raw materials uniformly, and then subjecting to magnetic-field press molding, isostatic pressing, sintering and tempering to obtain the sintered neodymium-iron-boron magnet.

Abstract: A butterfly valve includes a valve body and valve clack in the valve body. The valve body is installed with at least one sprinkler connected to an inlet valve outside the valve body for purging the inner surface of butterfly valve In the middle of the valve clack is a horizontal drainage tray, one end of which is closed and the other is water outlet, and the valve clack is equipped with at least one drain hole connected to the drainage tray; the sprinkler is above the drainage tray. This invention can be filled with corresponding media for online cleaning, sterilization and drying of non-sterile areas of a butterfly valve group after conveying the powder to realize repeated butt-joints.

Abstract: A butterfly valve includes a valve body and valve clack in the valve body. The valve body is installed with at least one sprinkler connected to an inlet valve outside the valve body for purging the inner surface of butterfly valve in the middle of the valve clack is a horizontal drainage tray, one end of which is closed and the other is water outlet, and the valve clack is equipped with at least one drain hole connected to the drainage tray; the sprinkler is above the drainage tray. This invention can be filled with corresponding media for online cleaning, sterilization and drying of non-sterile areas of a butterfly valve group after conveying the powder to realize repeated butt-joints.