The difference between globe valve and cut-off valve

China cast iron globe valve supplier today to share with you the globe valve and cut-off valve differences and structure introduction.

Valves can be used to control the flow of various types of fluids such as air, water, steam, various corrosive media, mud, oil, liquid metals, and radioactive media. According to the material, the valve is divided into cast steel valve, stainless steel valve, chrome molybdenum steel valve, chrome molybdenum vanadium steel valve, double phase steel valve, non-standard custom valve material. Valves can be used to control the flow of various types of fluids such as air, water, steam, various corrosive media, mud, oil, liquid metals, and radioactive media.

The shut-off valve and the cut-off valve valve are two of the many valves. I believe many people have mixed the shut-off valve with the shut-off valve. Many people think that the cut-off valve is the shut-off valve. The shut-off valve is a commonly used shut-off valve, which is mainly used to connect or cut off the medium in the pipeline. It is generally not used to regulate the flow. The shut-off valve is suitable for pressure and temperature range, but it is generally used for medium and small diameter pipelines. The shut-off valve, also known as a closed-circuit valve, acts to turn the medium in the line on or off. The cut-off valves include gate valves, globe valves, plug valves, diaphragm valves, gost ball valves, and butterfly valves.

 Globe Valve

The type of the shut-off valve is divided into an external thread type and an internal thread type according to the position of the stem thread. According to the flow direction of the medium, there are straight-through, direct-current and angular. The gost globe valve is divided into seals, with a packing seal stop valve and a bellows seal stop valve. The structure of the shut-off valve body is straight-through, direct-flow and right-angle. Straight-through is the most common structure, but its fluid resistance is greatest. DC fluid resistance is small, and it is mostly used for fluids containing solid particles or high viscosity. The right angle valve body is mostly forged, suitable for small through, high pressure shut-off valves.pressure shut-off valves.

Types of globe Valves and selection principles

The globe Valve is believed to be well understood by many people. For its type and how to choose it, it is also a fog. Today, the Gost globe valve manufacturers introduces the stop valve.

Commonly used globe Valves are as follows:

1) Angle type: In the angle type, the fluid only needs to change the primary direction so that the pressure drop through the valve is smaller than that of the conventional structure.

2) DC type: In the direct current or Y shape, the flow path of the valve body is inclined with the main flow path, so that the degree of damage of the flow state is smaller than that of the conventional one, and the pressure loss through the valve is correspondingly small.

3) Plunger type: This form is a conventional variant. In this valve, the flap and seat are usually designed based on the principle of the plunger. The valve flap is polished to form a plunger that is coupled to the valve stem, and the seal is achieved by two elastomeric sealing rings that are placed over the plunger. The two elastomeric seals are separated by a collar and the seal around the plunger is pressed by the load exerted on the bonnet by the bonnet nut. The elastomeric seal can be replaced and can be made from a wide variety of materials. The valve is mainly used for "opening" or "off", but with a special form of plunger or special collar, it can also be used to regulate flow. .

The most obvious advantage is that during the opening and closing process, the friction between the valve flap and the sealing surface of the valve body is smaller than that of the gate valve, so it is wear-resistant. Its opening height is generally only 1/4 of the diameter of the seat channel, so it is much smaller than the gate valve. Usually there is only one sealing surface on the valve body and the valve flap, so the manufacturing process is better and easy to repair.

The selection principle is:

1. The forge steel globe valve should be used on the pipeline or device of high temperature and high pressure medium. Such as thermal power plants, nuclear power plants, high-temperature, high-pressure pipelines of petrochemical systems.

2. The globe Valve is used on the pipeline where the flow resistance is not strict. That is, the place where the pressure loss is not considered.

3. Small valves can be used with needle valves, instrument valves, sampling valves, pressure needle valves, etc.

4. There are flow adjustment or pressure regulation, but the adjustment accuracy is not high, and the pipeline diameter is relatively small, such as the nominal diameter of ≤ 50mm pipeline, should be used.

5. For small chemical fertilizers and large chemical fertilizers in synthetic industrial production, high pressure angle type or high pressure angle type throttle valves with nominal pressure PN160 nominal pressure 16MPa or PN320 nominal pressure 32MPa should be used.

6. In the desiliconization workshop and the easy coking pipeline in the production of alumina Bayer method, it is easy to select the DC type or DC type throttle valve with the valve body separated, the valve seat can be removed, and the carbide seal pair.

Forge Steel Globe Valve

In summary, it is some introduction to the type of globe valve and the selection principle, I hope to help you understand it. Our company provides wholesale angle globe valve. If you want to know more about the consultation, please contact us and we will provide you with professional services.

Standard for hydraulic control valves

Hydraulic control valve is an important part of water conservancy engineering  needs, related to the quality and safety of the project, hydraulic control valve  is the pipeline itself medium pressure as a power source, open and close,  regulation, the leading valve and system small pipeline different combination,  can have nearly 30 kinds of functions, now gradually get more universal use.

Pilot valves rely on as the control object of the water level and pressure  changes and action, because the pilot valve type is many, can be used alone or  several combination, can make the main valve to achieve the water level and  water pressure and flow, such as the function of separate or compound  adjustment. However, the main valve is similar to the globe valve, when the  valve is fully open, its pressure loss is much larger than other valves, and the  closer the loss coefficient of each opening degree is to the full close, the  greater the increase, the larger the valve diameter is more significant.

The valve with the above characteristics, in close to full closure, the  action of the disc is accelerated, easy to send the water hammer (water impact  pressure), close to full closure, the valve action is slower, the better, so can  set throttle mechanism on the disc. In addition, the pilot valve throttling and  action part should try to avoid setting special small aperture, so as not to  block. If necessary, add filter screen, periodical maintenance and set up bypass  pipeline. This kind of valve is promising for development and use.

Hydraulic control valve is water pressure control valve, it consists of a  main valve and its attached pipe, pilot valve, needle valve, Stainless Steel Ball Valve and  pressure gauge.

Use of hydraulic control valves, the first to pay attention to the selection.  Improper selection will cause water and air leakage phenomenon. When selecting  hydraulic control valve, the displacement of hydraulic control valve must be  selected by multiplying the equipment's steam consumption per hour by 2-3 times  the maximum condensation water. In order to ensure that the hydraulic control  valve can discharge condensate as soon as possible when driving, rapidly  increase the temperature of heating equipment. Hydraulic control valve discharge  energy is not enough, will cause condensate can not be discharged in time,  reduce the thermal efficiency of heating equipment.

GOST Gate Valve

When choosing hydraulic control valve, hydraulic control valve cannot be  selected with nominal pressure, because nominal pressure can only mean hydraulic  control valve shell to bear the pressure class, hydraulic control valve nominal  pressure and working pressure is very different. So according to the working  pressure difference to choose the hydraulic control valve displacement. Working  pressure difference refers to the difference between working pressure before  hydraulic control valve and back pressure at the outlet of hydraulic control  valve.

The choice of hydraulic control valve requires accurate steam drainage  resistance, high sensitivity, can improve the utilization rate of steam, no  leakage of steam, reliable performance, high back pressure rate, long service  life, easy maintenance is the preferred condition.

Hydraulic control valve is a use of water self-embellish valve body, without  adding oil lubrication, such as the main valve parts damaged, please according  to the following instructions for disassembly. (note: the commonly consumed  damaged products in the inner valve are diaphragm and type ring, and few other  internal parts are damaged)

1. First close the Stainless Steel Gate Valve at the front and rear ends of the main  valve.

2. Loosen the coupling screw on the main valve cover to release the pressure  in the valve.

3. Remove all screws, including nuts for necessary copper pipes in the  control line.

4. Remove bonnet and spring. 5. Remove the shaft core, diaphragm, piston,  etc. Do not damage the diaphragm.

6. After taking out the above items, check whether the diaphragm and type  ring are damaged; If there is no damage, do not fight for the internal parts by  yourself.

7. If damage is found to the diaphragm or the molded coil, loosen the nut on  the shaft core, decompose the diaphragm or the molded coil step by step, remove  and replace it with a new diaphragm or the molded coil.

8. Inspect the inner valve seat and shaft in detail to see if there is any  damage. If there is any other debris inside the main valve, clear it out.

9. Assemble the replaced parts and components in the reverse order and  install the main valve. Note that the valve should not be stuck.

Factors to consider when selecting a pressure reducing valve

Principles for selecting pressure-reducing valves for industrial steam  pipelines  shared by Valve China Manufacturer.

Selection principle of pressure reducing valve for industrial steam  pipeline:

1. First of all, according to the working process requirements, the selection  of the right type of pressure reducing valve;

Small load and control pressure requirements are not high position can choose  a simple structure of direct action pressure reducing valve, for all other  situations, pilot pressure reducing valve is the choice, especially harsh  working conditions, such as downstream pressure less than 1barg, must choose  diaphragm pilot pressure reducing valve.

2. The selection must be based on actual working pressure (primary pressure  and secondary pressure) and flow rate.

Any type of control valve can not be too large, pressure relief valve is the  same, prefer to choose small can not choose large.

Valve China

Because the disc is too close to the seat, wet steam flow through the  erosion, wire phenomenon. In addition, because any small movement of the disc  can lead to large fluctuations in the flow through the valve, it is difficult  for the valve to accurately control the pressure, the more unstable the  pressure, the more frequent the valve action, the more severe the valve wear,  the shorter the life. So the valve selection is too large, not only cost  increase, valve China life will be shortened, pressure is not so stable!

3. Diaphragm pilot pressure-reducing valve is recommended for working  conditions with secondary pressure lower than 2barg; Diaphragm pilot type  pressure reducing valve is recommended for dn15-50 caliber. For DN65 caliber and  above, and the secondary pressure is greater than 2barg working conditions, it  is recommended to use piston pilot type pressure reducing valve.

4. For the front does not install a soda separator, it is recommended to  choose piston pressure reducing valve, because the piston structure is durable,  strong water hammer resistance ability; The diaphragm relief valve may break the  diaphragm each time it is turned on due to the impact of the huge water  hammer.

However, no matter what kind of pressure relief valve is used, once water  enters, the pressure relief valve will fail and cannot control the pressure,  which must be manually reset and re-adjusted. Of course, if the internal parts  are damaged, the parts or valves must be replaced.

5. For the working condition with large pressure difference, two  pressure-reducing valves are selected in series to perform secondary pressure  reduction. Typical working conditions are boiler thermal deaerator; If the flow  rate is too large or the flow rate varies too much, choose two or more  pressure-reducing valves in parallel, as described in section 6.5.

Selection principle of pressure reducing valve for industrial steam pipeline

Pressure stability and sensitivity to the pressure response after the valve  depends on the ratio between the piston chamber or diaphragm chamber and the  diameter and opening of the guide valve. The larger the ratio is, the better the  stability is, but the worse the sensitivity is, and vice versa. So manufacturers  in the design of pressure relief valve, need to do a comprehensive consideration  of two factors, stability and sensitivity of the balance, the ratio should not  be too large or too small. Too much proportion will cause slow response,  pressure drop, unable to recover in time; Too small ratio will cause pressure in  a small range of frequent beating, resulting in internal parts wear and tear,  leading to reduced valve life. Therefore, Valve manufacturer in the production and  development of pressure relief valve, must take into account the stability and  sensitivity of the two requirements. At present, the design of more perfect  pressure relief valve, have been completely solved these problems. However,  considering the requirements of field working conditions and secondary pressure,  diaphragm type is suitable for some working conditions, while piston type is  suitable for some working conditions. The selection principle of steam pressure  reducing valve according to the use requirements of the selected type and  pressure regulating accuracy, and then according to the required maximum output  flow to choose its size. When determining the air source pressure of the valve,  it should be greater than the output pressure of 0.1mpa. The steam pressure  reducing valve is generally installed after the water filter, before the oil  mist or value setting device, and pay attention not to the inlet and outlet of  the reverse connection; The knob should be relaxed when the valve is not in use,  so as not to affect the performance of the diaphragm due to its frequent  deformation under pressure.

Valve China

Principles for selecting pressure-reducing valve for industrial steam  pipelines

1) the fluctuation of the inlet pressure of the steam reducing valve should  be controlled at 80% ~ 105% of the given value of the inlet pressure. If the  range is exceeded, the performance of the reducing valve will be affected.

2) in general, the pressure behind the valve of the steam reducing valve Pc  should be less than 0.5 times the pressure before the valve, that is, Pc<  0.5p1. Each spring of the steam reducing valve is only applicable to a certain  outlet pressure range, beyond which the spring should be replaced.

3) in the medium working temperature is relatively high occasions, the  general selection of pilot piston type steam pressure reducing valve or pilot  bellows steam pressure reducing valve.

4) medium for air or water (liquid) occasions, generally appropriate to  choose the direct action of the film type pressure-reducing valve or pilot film  type pressure-reducing valve.

5) medium for the occasion of steam, should choose the pilot piston type  steam reducing valve or pilot bellows reducing valve.

6) for the convenience of operation, adjustment and maintenance, the steam  pressure reducing valve should be installed in the horizontal pipe.

Explosion-proof electric PVC ball valve

Installation and maintenance of explosion-proof electric PVC Ball valve China electric PVC ball valve has a maintenance free period, depending on its normal working conditions, maintain a harmonious temperature/pressure ratio and reasonable corrosion data and other factors. What should we pay attention to during its maintenance? Electric plastic ball valve is made of electric actuator with Ball Valve, the whole has light weight, strong corrosion resistance, is widely used in many fields, such as general pure water and drinking water pipeline system, drainage and sewage pipeline system, salt water and seawater pipeline system, acid and alkali and chemical solution system and other industries. The electric actuator adopts integrated design. The switch can be directly adjusted by input 220V power supply, or the servo module can be built in. The operation can be controlled by input control signal (4-20madc or 1-5vdc) and single-phase power supply. And electric plastic ball valve quality is recognized by the majority of users.

The main features of installation and maintenance of explosion-proof electric PVC ball valve are as follows:

(1) compact structure and beautiful appearance.

(2) light weight and easy installation.

(3) strong corrosion resistance, wide range of applications.

(4) the material is sanitary and non-toxic.

(5) wear resistance, easy disassembly, easy maintenance.

Product features:

1. Wide range of temperature: -40℃~+95℃

2. Extremely strong and tough

3. Excellent chemical corrosion resistance

4. Flame retardant performance is self-extinguishing

5. Low thermal conductivity, about 1/200 of the steel

6. The content of heavy ions in the medium reaches the ultra-pure water standard

7. Health indicators meet the requirements of national health standards

8. Pipe wall is smooth and smooth, with small friction resistance and adhesion when conveying fluid

9. Light weight, equivalent to 1/5 of steel pipe and 1/6 of copper pipe

10. Easy installation, can be connected by flange, by order, etc

11. Excellent aging resistance and uv resistance, which greatly extends the normal service life compared with other piping systems

Solve the problem of reducing valve in city water supply

 (1) keep dirt and sundries away from the pressure-reducing valve pressure relief guarantee system. Newly built or revamped pressure relief system pipe network, is likely to leave sand, hemp, debris. Before putting into operation, generally should carry on the water flushing, after meeting the cleaning requirements, install the pressure reducing valve and filter core, so as to avoid sundries into the pressure reducing valve, reducing valve core phenomenon. After the system enters the work, it is closely related to the flow capacity of the filter set on the system to ensure the smooth flow of the pressure relief system. If the filter element is seriously adsorbed by sundries, it will affect the work of the pressure reducing valve. Therefore, it is necessary to conduct regular inspection on the filter to timely pollute. Practice shows that this work is carried out every 2 to 3 months, and some adjustable (spring-type, thin-film) pressure-reducing valves, the main valve or pilot valve itself to set a filter, also need to regularly disassemble and wash the filter element.

(2) the pressure-reducing valve China set prepared by 1 should be rotated regularly. Most of the high - rise building water pressure relief valve pressure relief support system, is set up in the vertical water supply, generally located on the main water supply area. Considering the water reliability of many users (the residential area has dozens to hundreds of households, public buildings such as hotels, restaurants, each area has dozens of rooms... ), pressure reducing valve shall be installed side by side in design (1 for 1). The pressure relief channel is equipped with gate valve or butterfly valve on both sides, which can open and close any pressure relief channel. In order to make the parallel two sets of pressure relief valve channels work normally, it is routine to exchange once a month, and the pressure relief channel remains stagnant water and scale, and the valve core of pressure relief element will be stuck and fail.

Valve Supplier China

Upon the arrival of the water supply pressure-reducing valve China set, preliminary acceptance of the valve set components shall be conducted in accordance with the design requirements. The preliminary acceptance inspection shall be conducted jointly by the construction unit and the on-site project supervisors.

The preliminary acceptance of the solution of the pressure reducing valve fault in urban water supply shall include the following contents:

1. The model, specification and performance parameters of valve assembly should be consistent with the design requirements;

2. The components, accessories and spare parts of the pressure-reducing valve group should be complete;

3. The inspection report, qualification certificate, quality guarantee certificate and other technical data of the pressure-reducing valve group should be complete;

4. For domestic water supply system or direct drinking water pipeline system, the water supply pressure-reducing valve group shall have a copy of the type inspection of provincial or above quality, sanitary supervision and inspection institution and the sanitary inspection report of water-related products, and shall be stamped with the seal of the manufacturer;

5. The installation and operation instructions and supply list of valve assembly components should be complete;

6. Valve assembly package intact, appearance without defect and bruise;

7. If necessary, it may entrust relevant departments to conduct on-site sampling reinspection.