Introduction to the Function, Principle, and Characteristics of Globe Valves

 Globe valves are used to cut off the flow of media, and are suitable for situations that require frequent opening. The sealing parts of a globe valve are the valve disc and valve seat. In order to ensure a tight closing of the globe valve, the mating surface of the valve disc and valve seat should be ground or a gasket should be used. The sealing surface can also be embedded with corrosion-resistant and wear-resistant materials such as bronze and stainless steel.The valve disc and valve stem of the globe valve are connected in a movable manner to ensure a tight fit between the valve disc and valve stem. The lifting and lowering of the valve disc of a globe valve is generally controlled by the valve stem. The upper part of the valve stem is a handwheel, and the middle part is a threaded and packing sealing section. The function of the packing is to prevent the internal medium of the valve body from leaking along the valve stem.

The function of a shut-off valve

1、 The main function of a shut-off valve in a pipeline is to cut off or connect fluid. The regulating flow of a shut-off valve is better than that of a gate valve. However, a shut-off valve cannot be used to regulate pressure and flow for a long time. Otherwise, the sealing surface of the shut-off valve may be eroded and corroded by the medium, which may damage the sealing performance.
2、 Globe valves can be used in pipelines such as water, steam, and compressed air, but they are not suitable for medium pipelines with high viscosity, easy coking, and sedimentation to avoid damaging the sealing surface.

The principle of a shut-off valve

The valve disc of the globe valve moves vertically along the centerline of the valve seat, relying on the spinning of the valve stem thread to make the sealing surface of the valve disc of the globe valve closely adhere to the sealing surface of the valve seat, thereby blocking the flow of medium.

Advantages of shut-off valves

1. Small work schedule and short opening and closing time.
2. Good sealing performance, low friction between sealing surfaces, and long service life.
3. Good regulation performance.

Disadvantages of shut-off valves

1. The installation length is relatively long, and the resistance to medium flow is high.
2. The structure is relatively complex, making manufacturing and maintenance difficult.
3. The fluid passes through the valve seat from bottom to top, with high resistance and a greater force required for opening and closing.
4. Not suitable for media with particles, high viscosity, and easy coking.

评论

发表评论

此博客中的热门博文

The bonds between PSA(Pressure Swing Adsorption) and High Performance Butterfly Valve

图片
  High performance butterfly valves ： Generally refers to  double eccentric butterfly valve  and  triple eccentric butterfly valve ,due to their excellent working performance and high sealing ability (compared with concentric butterfly valve) are widely used in petrochemical,power plants,metallurgy,civil heating fields.Eccentric butterfly valves have the good working performacne to meeting sever and strict requirements in many different industries.Today, we are going to introduce the application of eccentric butterfly valve in air separation for making oxygen,hydrogen,CO etc. At present,the mature air separation system is PSA(Pressure Swing Adsorption),it need certain number of programmed valves (valve parts usually double or triple eccentric butterfly valve) in its pipeline system to control and adjust the medium. FEIDA  double (and tripple) eccentric butterfly valve are widely used in this kind of PSA system due to the valves' excellent features: 1-Long service life,on-off 1 mill
阅读全文

Brief introduction of FEIDA VALVE | China double offset butterfly valve manufacturer

图片
  FEIDA VALVE is the top ranking  Chi na  double offset butt erfly valve  man ufacturer  aslo a top ranking   Stainless Steel Resilient Gate Valve manufacture r . The annual output of high performance butterfly valve and stainless steel soft seated gate valve is more than 100,000,000 set. The API 607 fire safe high performance butterfly valve is also in FEIDA VALVE product range. Our fire safe butterfly valve is certificated by American Petroleum Institute (API) according to API 607 standards. FEID AVALVE stainless steel resilient gate valves are designed with built-in safety in every detail. The wedge is fully vulcanized with FEID AVALVE’s own drinking water approved EPDM rubber compound. It features an outstanding durability due to the ability of the rubber to regain its original shape, the double bonding vulcanization process and the sturdy wedge design. The triple stem seal system, the high strength stem and the thorough corrosion protection safeguard the unmatched reliability. FEI
阅读全文

What is difference about zero, double and tripple offset butterfly valve?

图片
Choosing the wrong type of valve can be detrimental to your operation. There are a few different types of  butterfly valves  on the market, including the zero offset, double offset, and triple offset. Zero Offset Also known as a concentric design, this is common in general service ‘resilient seated’ or ‘rubber seated’ butterfly valves. The stem and disc are centered in the seat of the valve, all of which are centered in the body of the valve. The disc is in constant contact with the seat. An advantage of this valve is the media going through the valve will not contact the body, since the seat is constructed as a sleeve or cartridge inside of the body. Zero offset butterfly valves are used in basic and specialty liquid and gas applications up to 200 PSI and up to 400 deg F. The zero offset butterfly valve can handle chemicals, coatings, food, some solids, and abrasive applications. The zero offset butterfly valve is available in epoxy coated cast iron and stainless ste
阅读全文