The sealing performance of a single union ball valve x9201-t white refers to the ability of the valve seal to prevent medium leakage, and is the most important technical performance index of the valve. Media leakage can cause material loss, environmental pollution and even accidents. For flammable, explosive, toxic or radioactive media, the sealing performance of a valve that is not allowed to leak refers to the ability of the valve seal to prevent media leakage, which is the most important technical performance index of the valve. Media leakage can cause material loss, environmental pollution and even accidents. For flammable, explosive, toxic or radioactive media, leakage is not allowed, so the valve must have reliable sealing performance.
Valve sealing technology has undergone tremendous development from its birth to the present. So far, the valve’s sealing technology is mainly embodied in two aspects, namely static sealing and dynamic sealing. Static sealing Static sealing refers to the formation of a seal between two static sections. The main sealing method is to use gaskets. There are many types of gaskets, the following are commonly used.
① Flat washer: a flat washer between two fixed parts. Generally divided into plastic flat washers, rubber flat washers, metal flat washers and composite flat washers according to the materials used.
② O-ring: a washer with an O-ring cross section. Because its cross-sectional shape is O-shaped, it has a certain self-tightening effect, so the sealing effect is better than that of a flat gasket.
③ Washer: A washer that wraps one material on another material. Such gaskets generally have good elasticity and can enhance the sealing effect.
④ Special-shaped washer: a washer with an irregular shape. Including oval washers, diamond washers, gear washers, dovetail washers, etc. These washers generally have a self-tightening effect and are mostly used for high and medium pressure valves.
⑤ Wave washers: wave washers. This kind of gasket is usually composed of metallic materials and non-metallic materials, and has the characteristics of small compression force and good sealing effect.
⑥ Roll-up washing machine: Thin metal belt and non-metal belt are closely connected to form a washing machine. This gasket has good elasticity and good sealing performance. Dynamic sealing Dynamic sealing is a kind of sealing problem during the relative movement of the valve. It does not allow the medium flow to leak with the movement of the valve stem. The main sealing method is to use a stuffing box. There are two basic types of stuffing boxes: gland type and compression nut type. The gland type is currently the most widely used form. Generally speaking, the gland can be divided into combined type and integral type. Although each form is different, it basically contains the pressure of the bolt. Compression nut types are usually used for smaller valves. Due to its small size, the compression force is limited. In the stuffing box, because the packing is in direct contact with the valve stem, all requirements for the packing are good sealing, low friction coefficient, adaptable to the pressure and temperature of the medium, and corrosion resistance. At present, the commonly used fillers are rubber O-shaped
Ring, PTFE braided packing, asbestos packing and plastic molding packing. Each kind of packaging has its applicable conditions and scope, which can be selected according to specific needs.
Post time: Jan-06-2022