Although the seal is small, it is a matter of great importance. "Don't lose the overall situation with small profits" should be the first condition for the whole enterprise to make decisions and choose seals. Modern managers should be very conscious of the serious negative effects of leakage caused by careless selection of seals. Innumerable blood lessons are always warning us: a small seal used by the inadvertent huge crisis, it caused by the loss is not its equal value, in seconds of the loss of raw materials, costs and even the most valuable life of the loss of human life.
Faced with many different manufacturers, different performance, different specifications of seals, many customers are often at a loss what to do. Or unnecessary loss due to the lack of accurate description of the order. In view of the above problems we often encounter, we suggest that you do as much as possible when ordering: provide the real sample, so that we can measure the material, measure the size, and provide the most accurate product.
Provide drawings or pictures, and indicate the name, material, shape and size requirements of the products. For example, the order gasket: mark the name of the gasket (such as the winding gasket, the outer ring) material (such as #316 steel), the size (outer diameter of the outer ring, the outer diameter, the inner diameter, the winding part thickness by the reinforced ring thickness (mm);
Gasket size representation method:
Basic type 1 -- outer diameter * inner diameter x thickness (mm)
With inner ring 2, outer diameter, inner diameter, inner ring diameter, thickness (mm).
Outer ring 3 outer ring outer diameter, outer diameter of winding part, inner diameter, thickness of winding part, thickness of reinforcing ring (mm).
4 inside and outside ring, outer ring outer diameter, outer diameter of winding part, inner diameter of winding part, inner diameter of inner ring, thickness of winding part, thickness of reinforcing ring (mm).
Supply condition condition. For example, the use of temperature, pressure and media corrosion, maintenance conditions, environmental requirements, price costs, data can be fax to our company, we can provide real samples according to the working conditions, until the customer trial success.
The gasket used in the flange connection must confirm the form of the flange butt: flat flange (including Ping Falan with protruding table), concave and convex flange, and tenon groove flange. At the same time, we must confirm which standard the flange applies to. How can we use and purchase the seal properly? Medium, temperature, pressure and working conditions should be important factors. For example, in the case of low pressure, with the use of plastic flange butt (PN<6kg), the choice of hard sealing parts, such as F4 or metal material, will leak because of improper selection of materials, and if the graphite material is used, it will get better effect due to the special effect of flexible, and vice versa.
In addition, in the working environment of chemical medium, it is necessary to match the different sealing medium reasonably to achieve good effect, otherwise the unexpected chemical change will happen easily. So any violation of seal selection will lead to unthinkable consequences.
The general gasket structure has the following kinds of reference: 1..
A. flat cushion: the material is made of medium pressure asbestos, non asbestos, oil resistant asbestos, polytetrafluoroethylene, graphite gasket or reinforced graphite gasket, metal flat mat, special metal gasket and so on.
B. winding gasket: the outer ring or the inner and outer ring (convex flat flange multipurpose); the inner ring (the concave and convex flange commonly used); the basic type (without inner and outer ring), the groove flange special sealing surface is narrow, flat welding flat flange, the seal face is wider, equivalent to the inner and outer ring winding gasket. It must be noted which country is the standard of the flange.
2., there are many kinds of packing for rotating and pulling the shaft seal. For example, the flexible graphite ring (separated and not open), a variety of materials woven into the root (or packing ring), a variety of material internal and external skeleton oil seal YX ring and O ring and so on.
3. seal products for special parts. There are various sealing strips, PTFE ball valve holders, graphite rings and rubber parts, butterfly valves and so on.
What should be paid attention to when installing the seal? 1. do not damage the sealing surface of the surface of the seal or the sealing property of the seal line. The sealing performance of the plane seal depends on the two end surfaces. The sealing performance of the hydraulic seal depends on the lip and mouth line associated with the hole or shaft. These parts are made up of the special materials which are easily damaged by the warm, corrosion resistant, Nai Lao's graphite, rubber and fiber, which are soft and resilient. Special protection and care should be given in the process of transportation, installation and storage. Once damaged, there will be great hidden dangers for sealing parts.
Can not be forced to install some seals in the slot shaped packing letter, at this time the need to tighten installation, construction can not be rough, barbarous, strong action is bound to destroy the original prefabricated structure of the seal, which is like the prefabricated concrete broken into the required parts will inevitably lead to disaster. The installation of such seals must be very careful and careful, and the embeddedness shall be carried out step by step.
When installing, we should pay attention to the balance and symmetry, and place the seal on the position that is just close to the effective sealing surface (or lip line). After the operation of the system, further observation and tightening of the seal are needed to prevent the burst of micro leakage caused by the change of working conditions (such as turbocharging) during the work of the system.
How to keep the seals that are not used temporarily? 1., prevent aging, avoid light, moisture-proof, smooth, and keep away from cold and heat sources.
2., do not press to keep the seal's natural state of relaxation.