工业上使用的平垫片一般由密封元件及内、外加强环组成，密封元件或称垫片本体是阻止泄漏的关键部分。其常用的材料有非金属材料，如柔性石墨、聚四氟乙烯、纤维增强橡胶基复合板等。此外，密封元件材料也可以是刚性或柔性的金属，通常用于压力和温度较高的场合。
The flat gasket used in industry is generally composed of sealing element and inner and outer strong rings. The sealing element or gasket body is the key part to prevent leakage. The commonly used materials are non-metallic materials, such as flexible graphite, polytetrafluoroethylene, fiber-reinforced rubber matrix composite plate, etc. In addition, the sealing element material can also be rigid or flexible metal, which is usually used in high pressure and temperature situations.
对于非金属材料的密封元件，通常插入金属材料予以增强，同时也方便了如石墨等易破碎材料密封元件的制造加工。增强材料可以是金属薄板或丝网,金属薄板常常采用冲刺孔的方式以提高增强效果和增加弹性，并通过粘结剂和辊压将它们贴合在一起。密封元件也可以可设一表面层或抗粘结处理层来增加密封效果和防止法兰密封面粘结。
For the sealing elements of non-metallic materials, metal materials are usually inserted to strengthen them, and it is also convenient for the manufacturing and processing of the sealing elements of fragile materials such as graphite. The reinforcing material can be metal sheet or wire mesh, and the metal sheet often adopts the way of punching holes to improve the reinforcing effect and increase the elasticity, and they are bonded together by binder and rolling. The sealing element can also be provided with a surface layer or anti bonding treatment layer to increase the sealing effect and prevent the flange sealing surface from bonding.
外加强环或外环材料均为实体金属，其作用是：
The material of outer ring or outer ring is solid metal. Its function is as follows:
帮助密封元件安装时对中；
Help to align the sealing elements during installation;
防止密封元件过份压缩而破坏；防止垫片吹出和减少法兰转动等。
Prevent the sealing element from being damaged due to excessive compression; prevent the gasket from blowing out and reducing the flange rotation, etc.
外加强环不与密封介质接触，因此不要求耐介质腐蚀，故常常由碳钢材料制成。外加强环还可以与密封元件制成一体，例如金属齿形垫片、波齿复合垫片。
The external strong ring does not contact with the sealing medium, so medium corrosion resistance is not required, so it is often made of carbon steel. The external strong ring can also be integrated with the sealing element, such as metal tooth gasket and wave tooth composite gasket.
内加强环或内环接触流体，其材料应能抵御密封介质的腐蚀。内加强环的作用是：
When the inner reinforcing ring or inner ring contacts the fluid, its material shall be able to resist the corrosion of the sealing medium. The function of the inner stiffening ring is:
防止密封元件与容器或管道法兰之间的空隙，以避免此空隙干扰流体的流动以及由此引起的流体对垫片的冲击。
Prevent the gap between the sealing element and the vessel or pipe flange, so as to avoid this gap interfering with the flow of fluid and the resulting impact of fluid on gasket.