How to choose a flat pad?
Flat washer is a component used to prevent bolt and nut locking. Where fasteners are used, flat pads are often used. How to choose a suitable flat pad? Flat gasket is a type of flat washer, mainly used to increase the contact area between screws and some large equipment, as well as to tighten them. When using flat gaskets, they are often suitable for nuts and nuts to be used in conjunction. When storing flat gaskets, they must be stored within the most effective sealing time and have the necessary important characteristics:
1. In harsh environments, it should be said that the flat gasket should be sealed to prevent leakage during operation at a certain temperature and pressure.
2. When connecting the flat gasket and the contact surface, it is important to ensure better sealing, just like the perfect effect.
3. When the gasket is subjected to pressure, it needs to have good wrinkle resistance under the influence of temperature, otherwise it will cause screw damage and result in hard air leakage.
4. Do not get infected when using flat pads.
5. The use of flat pads allows for easy disassembly, which is the greatest advantage of choosing a flat pad.
6. Remember to ensure normal use at relative temperatures when using flat pads.
In order to better use flat pads, it is advisable to choose flat pads coated with rust and corrosion resistant materials as much as possible. This not only saves time and effort, but also maximizes the effectiveness of flat pads.
When used with bolts and nuts, the selection criteria for flat washers are:
1. When choosing gasket materials, attention should be paid to the issue of electrochemical corrosion when different metals come into contact. The material of the flat pad is generally the same as that of the connected part, usually steel, alloy steel, stainless steel, aluminum alloy, etc. When conductivity is required, copper and copper alloys can be used.
2. The inner diameter size of the flat pad should be selected based on the larger diameter of the thread or screw. If the connected material is soft (such as composite material) or matches the spring washer, the outer diameter should be selected as the larger value.
3. When choosing to place a W washer under the bolt or screw head, to avoid interference between the rounded corner under the head and the washer, a flat washer with an inner hole chamfer can be used.
4. For important bolts with larger diameters or to increase their resistance to compression, steel washers should be used. Steel washers should be used for tension bolts or tension shear composite bolt connections.
5. Special gaskets are used in areas with special requirements, and copper gaskets can be used for conductive applications; Sealing gaskets can be used for those with air tightness requirements.
The function of a flat pad:
1. Increase the contact area between the screw and the machine.
2. Eliminate damage to the machine surface caused by spring washers when removing screws. When used, it must be: a flat spring pad, with the flat pad adjacent to the machine surface, and the spring pad between the flat pad and the nut. Flat pads are used to increase the force surface of screws. Spring pads provide a certain amount of cushioning protection when subjected to force to prevent screws from loosening. Although flat pads can be used as sacrificial pads.
3. But more often than not, it is used as a supplementary pad or flat pressure pad.
advantage:
① By increasing the contact area, components can be protected from damage;
② By increasing the contact area and reducing the pressure between the nut and the equipment, it provides protection.
Disadvantages:
① Flat washers cannot provide seismic resistance;
② Flat washers also have no anti loosening effect.