Cartridge Mechanical Seals For Centrifugal Pumps1

Cartridge mechanical seal is an aggregate that combines 7 main parts such as mobilization magic, static ring, spring, auxiliary seal ring, shaft sleeve, gland static gasket, etc. It can also be called cartridge mechanical seal. ), sometimes called a cassette seal.

Features: The cartridge mechanical seal has been combined into an aggregate, so it is more convenient and fast to install on the body, and the sealing is reliable. It is the development direction of mechanical seals at home and abroad.

Application: Cartridge mechanical seal is divided into single-end and double-end, and is widely used in flammable, explosive, corrosive, and high sealing leakage occasions.

Cartridge mechanical seal definition:

Cartridge mechanical seal is a combination of 7 main parts such as moving ring, static ring, spring, auxiliary sealing ring, shaft sleeve, gland static sealing gasket, etc. It can also be called a cartridge mechanical seal. Sea1). Sometimes called a cassette seal.      Cartridge mechanical seal has been assembled into an aggregate. Therefore, it is more convenient and fast to install on the body, and the sealing is reliable.      Cartridge mechanical seals are generally balanced mechanical seals. Its structural feature is that all parts are combined into one, the spring does not contact the material, and the balance type, internal flow, and positioning block can adjust the spring compression. Considering that it is easier to compensate when the dynamic/static ring is worn, a dynamic ring seal is designed.

Cartridge mechanical seal features:

The rotating and stationary parts are pre-assembled as a whole before installation. After inspection and pressure test are qualified, they are set on the inner shaft of the shaft seal box, fixed on the shaft with set screws, tighten the gland bolts, and remove the container spacer. Mechanical The seal can be in a parallel working state and put into operation. This not only facilitates assembly but also ensures assembly quality. Welded metal bellows mechanical seals are made of cartridge seals, which have the above advantages. The cassette seal is also a cartridge type mechanical seal. The static ring, moving ring, shaft sleeve, gland and auxiliary seal of this kind of seal are assembled together with a shaft sleeve before installation, which is convenient for checking the assembly quality. After passing the inspection, just tighten the sealing cover and tighten the screws. Such pre-assembled, inspected and tested sealing components are easy to ensure the quality of installation and assembly. this cartridge

(1) There is no need to measure the working length of the seal during installation;

(2) The shaft can be adjusted at any time;

(3) There will be no leakage problems at start-up because the seals are pre-tested;

(4) When installing, it is only necessary to tighten the sealing cover bolts, and the assembly quality is easy to ensure;

(5) Protect the sealing surface from debris contamination or damage due to operational errors before installation or start-up;

(6) The machinery and equipment can be readjusted after thermal expansion;

(7) The center can be customized by cooperation;

(8) It is easy to remove the seals for cleaning and inspection without disassembling the pump equipment. Cartridge mechanical seals are recommended for all mechanical seals in the API682 standard.

Cartridge mechanical seal advantages:

The pre-installation design structure of the cartridge mechanical seal device is simple to install and easy to operate, which simplifies the process of measurement and adjustment, and has the characteristics of easy installation and strong interchangeability. It avoids the damage of the sealing element caused by the installation of the mechanical seal when the equipment is overhauled, and reduces the maintenance cost. High-quality imported special ceramics, graphite with strong corrosion resistance, sintered carbide and other sealing materials are used to improve the service life of the mechanical seal.

Assembly method of cartridge mechanical seal

(1) Assembly of gland and bellows: The gland and bellows are connected with 6--12 bolts, and there are gaskets between them to prevent medium leakage.

(2) Hard ring positioning: First, fix the fixing ring on the positioning countersunk hole of the shaft sleeve, then put the gland and bellows assembly in to make it close to the fixing ring, and place the hard ring, wedge ring and rotating seat ring , After confirming the position of the rotating seat ring, slightly tighten the set screw of the rotating ring, connect the rotating ring and the hard ring with screws, and take out the fixing ring, the gland, and the bellows assembly.

(3) Alignment of the end face: When the rotating seat ring and the hard ring are connected to the shaft sleeve, keep the verticality of the end face. Generally, ensure that the end face runout is less than 0.05mm. On the assembly platform, after tightening the set screw on the rotating seat ring, use the dial indicator to align while tightening the screw connecting the rotating seat ring and the hard ring to ensure the vertical end face. Spend.

(4) Adjustment of the compression amount: The compression amount of the cartridge bellows mechanical seal is reflected in the thickness of the positioning block. But some users want a different amount of compression.