�� Being the Final Control Element in a system is not an easy job. To start with, you are blamed for any and all problems that crop up in the process. You are subjected to corrosion, high velocity, cavitation, flashing liquids, cryogenic temperatures, high temperatures, abrasion, and thermal shock. You are expected not only to throttle along through all this, but most likely, you are also being asked to act as a block valve燼nd shut off tight.

Emergency Shut-off Valve Shut-off Valve General Valve

���� As you work with control valves always keep in mind that a control valve only does what it is told to do.

���� A Control Valve is a power-operated device used to modify the fluid flow rate in a process system. Well, what happens if the power is cut off? When a Control Valve is sized or selected to do a particular job, one of the first questions you should consider is how that valve will respond in the event of a loss of signal or power. This is called its “fail-safe mode” and knowing the fail-safe mode is the key to troubleshooting it.

���� In most applications (about 80%), it is desirable for valves to fail closed. In other applications, you might want a valve to fail open or fail in place. Safety concerns and process requirements will mandate the fall mode of the valve.

When a valve is not sitting in its fail position, is is being told how and when to move by some external signal.

���� By the comments one hears, you would be led to believe that control valves sit around and think up things to do on their own. Perhaps this will some day be true when all control valves are “smart.”

���� If a Control Valve is observed in an unstable condition or appears to not be responding correctly to an input signal, remember that something is telling the valve to behave that way.

A control valve is only as strong as its weakest link.

���� When the 1965 Ford Mustang first appeared, it was powered by a 6-cylinder engine with a 3-speed transmission - but it had a 140 m.p.h.(225 k.p.h.) speedometer. The fact that it had a 140 m.p.h.(225 k.p.h.) speedometer did not mean it could actually travel that fast. In the same way, a control valve with a 600# rated valve body cannot throttle and shut off against 1440 pounds of pressure.

���� There are two basic types of Control Valves: rotary and linear. Linear-motion control valves commonly have globe, gate, diaphragm, or pinch - type closures. Rotary-motion valves have ball, butterfly, or plug closures. Each type of valve has its special generic features, which may, in a given application, be either an advantage or a disadvantage.

　　Recently, the city of Guiyang Water Supply Corporation meter reading in reading found that many people use the water heater in the hot water back to the time of the year imports of cold water, cold water pipe severely damaged (PVC pipe). To this end, the city’s tap water to alert the public of the water heater Check Valve is working correctly.

　　October 23, Guiyang City water meter reading head office in West Qianling quarters of a meter-reading unit found that within a meter of water and steam. MRs immediately knocked on the door of the household, along the observation of cold water pipe and found the water heater intake Department of PVC pipe a little hot. After careful examination, users just turn off the water heater, the excess water back into the PVC pipe, open to inspection found that a non-return valve water heater is not working.

　　City tap water, according to marketing head Zhao Hong, deputy secretary-center, the recent return of more than Tanghuai PVC water pipe incident. I installed a table of the family, the house is more than PVC pipe cold water pipe, which is synthetic material of polyethylene, with a smooth wall, water resistance, health safety features, there is a ban on PVC pipe hot water circulation. Now residents of the home used by the direct-fired water heater-type or volume should be at the intake valve installed, regular maintenance and repair water heater, check valve is working correctly.

　　In addition, after the winter of the cold weather, the temperature dropped to minus 3 degrees Donglie water pipes are susceptible to the phenomenon. If people were found frozen water pipes, please do not hit with a hard object, the application of warm hot wet towel.

Swing Check Valve Y-Pattern Piston Check Valve Forged Steel Flange End Check Valve Flanged End Check Valve Piston Check Valve 800Lb Piston Check Valve 900Lb~1500Lb Pressure Sealing Swing Check Valve Butterfly Swing Check Valve Swing Check Valve Pressure-seal Piston Check Valve Flanged End Pressure-seal Piston Check Valve SCVX silence check valve

　At present, as a Butterfly Valve used for piping system off and flow control components, has been in petroleum, chemical, metallurgy, such as water and electricity in many areas has been very widely applied. In the public has to know the butterfly technique, the use of its seal in the form of sealed structure, sealing materials for rubber, PTFE, and so on. As the structure of the restrictions, adapting high temperature, high pressure and corrosion resistance, abrasion resistance, and other industries.

　　Present a more advanced three-eccentric butterfly valve is a hard metal seal butterfly valves, valve seats and valve components for the Siamese, the valve seat seal surfacing layer on the surface temperature, and corrosion resistance of alloy material. Multi-layer stack of soft-ring fixed in the on-board valve, butterfly valve that compared with traditional butterfly valve has a high temperature, the operation of the Light, Headstock friction-free, closed with the transmission of the torque increases to compensate for seal, to increase A butterfly valve sealing performance and extend the service life of the merits. However, this butterfly is still in the process of the use of the following:

　　First, because of hardware and software, multi-layer stack-ring fixed in the valve plate when the valve plate when the media always state their side to form a positive seal erosion, sheet metal laminated with the soft seal by erosion, sealing a direct impact on performance.

　　Second, the structural conditions of the structures do not meet the following path DN200 valve, the valve because of the overall structure of thick plates, large flow resistance.

　　Third, as a result of three eccentric structure of the theory of plate valve sealing surface between the seat and sealed by the torque transmission so that the valve seat to the pressure plate. Flow is a state, the higher the pressure medium sealed squeeze is tightening. When the media counter-current flow when the pressure increases as the medium plate and the valve seat between the units is less than the pressure on the media pressure, began to leak sealed. Tripe Eccentric Butterfly Valve wafer soft seat butterfly valve single eccentric manual wafer soft seat butterfly valve

　　Three two-way high-performance hard-eccentric butterfly valve seal, is characterized by: valve seat ring described by the soft T-shaped ring seal on both sides of the multi-layer film composed of stainless steel. Board seat and valve sealing surface of the ramp for the cone structure of the valve plate in the oblique cone surface temperature welding, corrosion resistance alloy material; fixed-conditioning in the ring between the board and a spring board regulation on the structure of the bolt assembly together. This structure effectively compensated with the sleeve valve between the stem and tolerance with the media under the pressure of the elastic deformation, to address the exchange of the two-way valves in the transmission medium in the process of sealing the existence of the problem. The use of soft T-piece stainless steel high-rise on both sides of the composition of the ring with a hard metal sealing and soft sealing the dual advantages of low temperature and high temperature in the circumstances, have zero leakage sealing performance. Pool tested positive state of flow (flow direction of medium and butterfly plate rotating in the same direction), the sealing surface pressure is the transmission of torque and medium pressure valve on the role of the board generated. Positive media pressure when the valve plate oblique cone surface and the valve seat sealing surface squeeze is tightening, the better the effect of sealing. When the current state, the valve seat between the board and sealed by the drive torque to the pressure plate so that the valve seat. With the back of increased media pressure, valve seats and valve plate between the units is less than the pressure on the media pressure, the adjustment ring in the spring after the store set by the deformation of the valve to the compensation board seat with the sealing surface of the tight Pressure to play the role of automatic compensation.

　　Therefore, this utility model, unlike existing techniques, in the valve installed on-board hardware and software, multi-ring, but directly installed in the valve body, the board in the middle seat and additional regulation is the ideal way of sealing the hard way . It can replace the valve, the valve and ball valve.

　　Globe valve is a common Globe Valve, or cut off access to the main pipeline in the media, not for general traffic regulation. Deadline to apply pressure valve, a large temperature range, it is generally used for medium and small-caliber pipe.

　　The main valve standard

　　GB12233-89 “Universal iron valves and valve lift-check valve”

　　GB12235-89 “universal valve steel flange connection with the Globe valve lift-check valve”

　　JB/T53174-94 “Globe valve product quality classification”

　　JB/T53165-92 “high-pressure balance valve product quality classification”

　　GB/T587-93 “marine bronze flange valve”

　　GB/T590-93 “marine cast iron flange valve”

　　GB8464-87 “thread connecting valve, the Globe valve, ball valve, check valve common technical requirements”

　　GB8465.2-87 “thread connecting valve, the Globe valve, ball valve, check valve size of the basic iron Globe valve”

Cast Steel Globe Valve Pressure Sealing Globe Valve Flanged End Globe Valve

　　With the development of our national economy and people’s living standards improved. Urban central heating system has been gradually replaced the household-based dispersion heating furnace, the current North Shenyang and other cities have been or are in the process of building large-scale central heating system, central heating system in the future will be toward large-scale, complicated direction. Such large-scale heating system, central heating, water hammer accident damage in the event of a strong, serious consequences, it is necessary to take active preventive measures to minimize and prevent water hammer phenomenon.

　　Check pipes in heating system is a very important component, check valve installed on the location and structure of the parameters and the closure of the curve on the heating system’s safety and bite on a lot of influence. If the proper use of check valve; be able to play a protective role of ice hammer; but if used improperly, not only for heating equipment can not play a role in the protection, and heating system will be in the pipeline great Shui Tang. Therefore, check valve on the water heating system with a hammer to study the role of very important practical and academic significance.

　　Transient fluid movement from the point of view; for check valve at the request of the power failure only to be turned on or off, but should be based on the flow of heating pipes in the situation on the headstock a certain speed. Inappropriate speed hoist will be in the pipeline system caused by a sudden rise or drop in pressure when the pressure on when it will big enough to appreciate caused by the rupture of the tube. For the plant to guarantee the security system must be reasonable to choose the form and structure of check valve closure of the curve to play the role of water hammer. In this paper, check valve in the heating system of water hammer, the establishment of check valve valve gate when the boundary conditions, the general analysis of the shortcomings of check valve valve and check valve water hammer characteristics of the study to optimize the closure of properties Elimination of water to prevent water hammer and reverse the mechanism, come to meaningful conclusions, the heating system in the correct choice and use of check valve with a guide.

The 300X slow close check valve is an intelligent valve intended for installation in the pump outlet of a high-rise buildings ?water supply system. When uses it effectively prevents the reverse flow of a medium, as well as water hammer-type phenomena. This valve utilizes a motorized valve, check valve and water hammer eliminator at the same time and can effectively increase the safety and reliability of a water supply system.It integrates such functions as slow opening, fast and slow closing in order to eliminate water hammer, so as to prevent the occurrence of pump-on water hammer and pump-off water hammer. The valve can automatically realize turning on/off according to the operation specification of the pump.By pressing the On/Off button of the pump motor; a large flow and small pressure loss can be achieved. Our slow shut-off check valve are suitable for use with pipes of 600 caliber and below.Pressure Rating: PN10. PN16. PN25/Class150Size Range: DN20mm-DN800mm (3/4″ - 32″)Test and inspection: GB/T 13927 API598.

Related Products of 300X slow close check valve:

700X Pump Control Valve, It belongs to Water Control Valve and Check valve.

The 700X Pump Control Valve is a kind of check valve intended for installation at outlets of pumps in high-rise buildings and other water supply systems to prevent reverse flow of the medium. When the pump is about to stop water supply, the valve first shuts off slowly by about 90% so as to avoid water hammer caused by the sudden shutdown of the pump. When the pump comes to a complete stop, the valve then shuts off completely so as to prevent the reverse flow of water pumped out. This can effectively protect the pump and avoid the reverse rotation caused by the impact of reverse flow. This product is an indispensable protective device at outlets of pumps.It has a streamlined design, can realize precise turning on/off through guidance and is controlled by the solenoid valve. Furthermore, our pump control valve is safe, reliable, effectively avoids water hammer, boasts a long service life and is easy to install and maintain.Pressure Rating: PN10. PN16. PN25/Class150Size Range: DN20mm-DN800mm (3/4″ - 32″)Test and inspection: GB/T 13927 API598.

Related Products of 700X Pump Control Valve:

700X Pump Control Valve, It belongs to Water Control Valve.

The 600X electrical control valve is a kind of waterpower operated valve that utilizes a solenoid valve as its pilot valve. It is normally used in automatic control for water supply and drain systems and other industrial systems.It is precise and quick in its response in the process of control and utilizes remote operations through turning on/off the management system via remote control signals. It can also replace gate valve and butterfly valve for application in large-sized electrically operated systems because the shut-off speed of the valve is adjustable and smooth shutoff can be realized without causing any pressure variation. This valve is small in volume and weight, simple to maintain and repair, easy to use, safe and reliable. Both 220VAC and 24VDC can be used for the solenoid valve and you can choose to use the constantly open or constantly closed valve according to you actual needs during a specific situation.Pressure Rating: PN10. PN16. PN25/Class150Size Range: DN20mm-DN800mm (3/4″ - 32″)Test and inspection: GB/T 13927 API598.

Related Products of 600X electrical control valve:

600X electrical control valve, It belongs to Water Control Valve.

200X pressure reducing valve is an intelligent valve that uses the self energy of the medium to regulate and control the pressure in pipes. The 200X pressure reducing valve can be used in domestic water supply,fire fighting water supply and other industrial water supply systems. The outlet pressure of the main valve can be regulated through the adjustment of the pressure reducing valve; the outlet pressure does not vary along with the inlet pressure and inlet flow. Accordingly, the outlet pressure can be safely and reliably maintained at a preset value and the preset value can be adjusted according to actual needs to obtain your pressure reducing goal. This valve is precise in pressure reduction, stable in performance, safe, reliable, easy, convenient to install and adjust and offers a long service life.Pressure Rating: PN10. PN16. PN25/Class150Size Range: DN20mm-DN800mm (3/4″ - 32″)Test and inspection: GB/T 13927 API598.

Related Products of 200X pressure reducing valve:

200X pressure reducing valve, It belongs to End Dimension.

===Body=== == The main pressure containing structure of the valve and the most easily identified as it forms the mass of the valve. It contains all of the valve’s internal parts that will come in contact with the substance being controlled by the valve. The bonnet is connected to the body and provides the containment of the fluid, gas, or slurry that is being controlled.

Globe valves are typically two-port valves, although three port valves are also produced. Ports are openings in the body for fluid flowing in or out. The two ports may be oriented straight across from each other on the body, or oriented at an angle such as a 90° angle.Globe Valves with ports at such an angle are called angle globe valves. A globe valve can also have a body in the shape of a y.

Bonnet

Provides leakproof closure for the valve body. The threaded section of stem goes through a hole with matching threads in the bonnet. Globe valves may have a screw-in, union, or bolted^[9] bonnet. Screw-in bonnet is the simplest bonnet, offering a durable, pressure-tight seal. Union bonnet is suitable for applications requiring frequent inspection or cleaning. It also gives the body added strength. A bonnet attached with bolts is used for larger or higher pressure applications. Bonnets also contain the packing, which is a wearable material that maintains the seal between the bonnet and the stem during valve cycling operations

Plug or disc (disk)

The closure member of the valve. Plugs are connected to the stem which is slid or screwed up or down to throttle the flow. Plugs are typically of the balance or unbalanced type. Unbalanced plugs are solid and are used with smaller valves or with low pressure drops across the valve. The advantages are simpler design, with one possible leak path at the seat and usually lower cost. The disadvantages are the limited size; with a large unbalanced plug the forces needed to seat and hold the flow off become impractical. Balanced plugs have holes through the plug. Advantages include easier shut off as the plug does not have to overcome static forces. However, a second leak path is created between the plug and the cage, cost is generally higher.

Stem

The stem serves as a connector from the actuator to the inside of the valve and transmits this actuation force. Stems are either smooth for actuator controlled valves or threaded for manual valves. The smooth stems are surrounded by packing material to prevent leaking material from the valve. This packing is a wear material and will have to be replaced during maintenance. With a smooth stem the ends are threaded to allow connection to the plug and the actuator. The stem must not only withstand a large amount of compression force during valve closure, but also have high tensile strength during valve opening. In addition, the stem must be very straight, or have low runout, in order to ensure good valve closure. This minimum runout also minimizes wear of the packing contained in the bonnet, which provides the seal against leakage.

Cage

The cage is part of the valve that surrounds the plug and is located inside the body of the valve. Typically, the cage is one of the greatest determiners of flow within the valve. As the plug is moved more of the openings in the cage are exposed and flow is increased and vise versa. The design and layout of the openings can have a large effect on flow of material (the flow characteristics of different materials at temperatures, pressures that are in a range). Cages are also used to guide the plug to the seat of the valve for a good shutoff, substituting the guiding from the bonnet.

Seat ring

The seat ring provides a stable, uniform and replaceable shut off surface. Seat rings are usually held in place by pressure from the fastening of the bonnet to the top of the body. This pushes the cage down on the lip of the seat ring and holds it firmly to the body of the valve. Seat rings my also be threaded and screwed into a thread cut in the same area of the body. However this method makes removal of the seat ring during maintenance difficult if not impossible. Seat rings are also typically beveled at the seating surface to allow for some guiding during the final stages of closing the valve.

Economical globe valves or stop valves with a similar mechanism used in plumbing often have a rubber washer at the bottom of the disc for the seating surface, so that rubber can be compressed against the seat to form a leak-tight seal when shut.

Many globe valves have a class rating that corresponds to the pressure specifications of ANSI 16.34. Bibcocks and sillcocks are variations of globe or stop valves used in plumbing. Needle valves are variations of globe valves where instead of a separate attached disc piece, the internal end of the stem is conically tapered to act as the disc to fit into a matching seat for fine flow adjustment. Other different types of valve usually are called globe style valves because of the shape of the body or the way of closure of the disk. As an example typical swing check valves could be called globe type.