21. April 2017 · Comments Off · Categories: BALL VALVE

The following are the most pupular seat option for ball valve

VIRGIN PTFE
Inert to most chemicals, low coefficient of friction, recommended for water, foodstuff and corrosive chemicals. FDA grade.
Colour: White

25% GLASS FILLED PTFE
Similar to 15% glass filled PTFE seats but better resistance to wear and deformation under load.
Colour: Gray-White with red stripe

15% GLASS FILLED PTFE
Similar to 15% glass filled PTFE seats but better resistance to wear and deformation under load.
Colour: Gray-White with red stripe

CARBON FILLED PTFE – NRG
Specially for steam and thermal oil, low  coefficient of friction, inert to most media.
Colour: Pale Black with white stripe
ULTRA HIGH MOLECULAR WEIGHT POLYETHYLENE (UHMWPE)
Good for nuclear, Tobacco, H2SO4 and chemical resistance applications, low coefficiant of friction.
Temperature limit of 93°C. Colour: Pale White with green stripe

PCTFE
Cryogenic applications such as oxygen, hydrogen, nitrogen and more, suitable for temperatures up to -270°C.
Colour: See-through White

CARBON FILLED PEEK®
Suitable for elevated temeperatures, good resistance under high pressure loads, low coefficient of friction, suitable for many corrosive applications.
Colour: Charcoal Black with yellow stripe

VIRGIN PEEK
Similar to filled PEEK® but higher coefficient of friction, suitable for nuclear, Tobacco, clean applications. FDA grade.
Colour: Beige

DEVLON
Devlon® V-API is a high molecular weight polyamide that is specifically tailored for high temperature/pressure. Applications in the offshore oil & gassector

06. June 2016 · Comments Off · Categories: Uncategorized

Why cryogenic ball valves prone to pull stuck motionless phenomenon, how should it be solved?

A: The low temperature ball valve(cryogenic ball valve) installed at room temperature, work at low temperatures large temperature range. If the design, improper installation, it is prone to heat stress or strain. At the same time, the ball valve is in the normal operating portion, circulation portion is low. To reduce cold damage, stem often do very long, it is easy to be deformed and stuck. Cryogenic ball valves(low temperature ball valves) are often rotated at room temperature flexibility at low temperatures is very tight, and even open. Valve stuck at low temperatures the main reasons are:
1)The installation, low temperature ball valve(cryogenic ball valve) and pipeline configuration unreasonable generate prestressing; or poor pipe cold compensation, at a low temperature ball valve(cryogenic ball valve) position change; or lack valve stent deformation at low temperature; or ball fixed properly, cold box at a low temperature deformation The influence of concentricity with the valve stem.
2)In the design, because of the different stem and the low temperature ball valve(cryogenic ball valve) sleeve material, the linear expansion coefficient is different. Usually the stem stainless steel, linear expansion coefficient of 1.73 × 10-6 ℃ -1; brass sleeve, linear expansion coefficient of 19.9 × 10-6 ℃ -1, i.e., greater than the contraction brass stainless steel, low temperatures may the threaded bite. Especially when using fine thread, threaded a temperature range of large and small thread gap, the phenomenon is more prone to bite.
3)In the operation, due to the low temperature heating is not complete at the ball, or valve packing at the water, causing freeze, or at room temperature, the valve is closed tight at low temperatures, making threaded chewed like.
To prevent hypothermia valve stuck phenomenon, the design should be broad trapezoidal screw threads; there should be a firm stand in the valve at the installation to prevent the valve with the stem pipe displacement and bending. Ball and low temperature cold box can be elastically fixed connection to prevent deformation of the stem and the body different heart; during the cold bare, to check and adjust the cryogenic valve installation in the cold state, when it was found jammed valve cooling When the phenomenon, adjustable valve mounting flange on the cylinder housing, so that the switch easily.
In operation, before the start of the heating should be complete, close the low temperature ball valve (cryogenic ball valve) when the principle of not leak, do not use excessive force.

Should you want to know more about butterfly valve from Reliable China valve manufacturer, please visit www.reliavalve.com or email us via sales@reliavalve.com.

14. September 2015 · Comments Off · Categories: BALL VALVE

Kinematic pair definition: direct contact with members consisting of two movable connection, which limits some relative movement between the two components, valves and seals deputy campaign is a concept, deputy of functional movement is to achieve on-off control, Sealing function is to ensure the sealing effect, valves and valve sealing pair deputy campaign together constitute the valve seals from valve manufacturer.

Deputy campaign not only on the valve has to participate in many mechanically has two members constitute a point of contact deputy campaign, lines and other elements are called kinematic pair elements. Deputy campaign a variety of classification methods:

1)In accordance with the contact form deputy campaign classification: face and motion in the lower sub-surface contact pressure contact portion, known as the low pair, and the dotted line is called high contact sports deputy, Vice easier than high low side wear .
2) According to the relative movement in the form of classification: the relative motion between the two members constitute deputy campaign plane motion if planar motion was deputy, if the space is called space motion movement pair, only a relative rotation between the two members The movement is called rotation deputy vice, only a relative movement between the two members of the movement called the move deputy.
3)According to deputy campaign introduced constraint Category: introducing a constraint deputy campaign deputy campaign called level deputy, introduced two constraints is called a secondary byproduct, as well as three, four, five deputy.
4) Classified according to the geometry of the contact section: can be divided into cylindrical deputy, Vice-plane and plane, spherical deputy, deputy spiral like.

Should you want to know more about valve from Reliable China ball valve manufacturer, please visit www.reliavalve.com or email us via sales@reliavalve.com.

 

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14. September 2015 · Comments Off · Categories: BALL VALVE

In order to achieve zero leakage sealing ball valve inside and outside, to save energy, protect the environment and improve work efficiency, valve must have a reliable sealing performance, ball valve sealing performance is the ball valve part of the sealing ability to prevent media leaks, it is under test conditions rated valve internal and external leaks. Contact points with the department, filler stem and the stuffing of the main parts of the opening and closing ball valve sealing member and the ball valve seat sealing surface between the body and bonnet connection which is called before a leak within the leak, also is commonly known as a bad relationship, it will affect the ability of the ball valve cut off media, for the cut-off valve, the internal leakage is not allowed, Leakage after the two called the leak, that media leaks from the valve to the valve outside , Leakage will result in material losses, environmental pollution can also cause serious accidents. The sealing performance of the valve is an important indicator of valve function and quality.

The ball valve leakage problem a serious threat to the normal operation of the device, and the operation of the ball valve and very difficult to find whether there is leakage, the survey results show that the use of a variety of petrochemical enterprises each with varying degrees of valve leakage problems exist, the reason there is a ball valve plate, seat sealing surface material does not meet the requirements, processing accuracy is not enough, gate valve plate, seat wedge angle does not match, the sealing surface varies in width, fit is poor, the shutter is not in place, and other factors related death. Such as: For flange cast steel gate valve, the sealing surface material code should refer to the hardness of sealing a relatively soft sealing surface material, other seal face materials shall be at least apparently corresponding carbide, and in fact there are only one valve sealing surface surfacing hard alloy and the other sealing surface of the bulk material is carbon steel, and put into use not long to occur due to wear and tear in the drain phenomenon. Another example of a piping system selected folder-off valve, seat material PTFE, the use conditions, the demand is not high, it is normal temperature and pressure, but found a large number of in trial run The ball valve closed lax, leakage severe that they cannot normally use, and finally had to replace a valve, removed examination found that the closed state of the ball valve plate and seat a great gap, even light. Analysis of the reasons may include the following: the structural design manufacture and assembly of precision unreasonable or ball valve seal pair fail to meet requirements; failure to require the construction and installation of the ball valve so that it put too much force; the construction process in welding slag, sand, metal shavings and other debris from entering the ball valve chamber, the sealing effect is affected. In fact, more practical, it is the most fundamental reason is that in the valve manufacture, transportation or installation process fails certain standard requirements to do so.

The explosive, toxic or radioactive medium, leakage is allowed, and therefore, the ball valve must have a reliable sealing performance.

Should you want to know more about ball valve from Reliable China valve manufacturer, please visit www.reliavalve.com or email us via sales@reliavalve.com.

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14. September 2015 · Comments Off · Categories: BALL VALVE

In addition cinder ball valve, spray ball valve pulverized coal, others, like the floating ball valve,trunnion mounted ball valve, V-type ball valve, eccentric semi-ball valve, three way ball valve, which has two seats, the first seal means that the inlet end seat acts as a seal, the back seal means that seal the outlet end of the seat from the actual principle is very simple, which is to seat sealing O-ring sealing surface on the outside of the seat within the differences and. There is also a two-way sealed DIB structure; its principle is to increase the O-ring, the inner circle within the valve seat ring, the outer ring outside the seat.

After the back seat seal trunnion  ball valve, the fluid pressure on the ball and seat effective force is small, therefore, the bearing load and friction torque are small, which gives the drive and bearing design, especially for low friction coefficient with self-lubricating properties, but the choice of compressive strength is low, there is a tendency of cold PTFE sliding bearings to provide a convenient, the disadvantage is that the valve seat seal: To ensure da> dw, if not reduce the valve channel cross-sectional area, it is necessary to increase the size of the ball and the body’s structure.

For the first seal, the back sealed on both sides of trunnion mounted ball valve, the advantage of reliable sealing performance, low bearing loads, so it is suitable for sealing particularly demanding situations, when the ball valve body cavity pressure P2 abnormally elevated, it cannot automatic pressure relief, therefore, when using double sealed ball transporting liquefied gas, the need to coat the body of a small safety valve.

When the fluid pressure PN≥16MPa, valve size DN = 80-200mm, the general use of the back seat seal, for delivery pressure PN≤10MPa corrosive media and gases, as well as valve size larger occasions, should be adopted valve seat before sealing, the sealing requirements are particularly stringent, or more dangerous media, we recommend using double-sided seal valve, in order to increase the sealing performance, reduce friction and wear seat, extend its life and to prevent the ball valve use due to damage caused by accident seat, oil seal structure can be added in the seat, but it must be noted that only the auxiliary oil seal from the seal, or as a temporary emergency measure, oil seal structure used for larger diameter and conveying gas trunnion mounted ball valve medium.

Should you want to know more about ball valve from Reliable China  valve manufacturer, please visit www.reliavalve.com or email us via sales@reliavalve.com.

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14. September 2015 · Comments Off · Categories: BALL VALVE

Ball valve has a small fluid resistance, the drag coefficient equal to the same length of the barrel; simple structure, small size, light weight; compact and reliable valve sealing surface material widely used plastic, sealing, and has also been widely used in the vacuum system ; easy to operate, opening and closing rapidly, fully closed as long as the rotation 90 °, easy remote control from fully open to; easy maintenance, simple ball valve, seals are generally activities, the removal replacement is more convenient; in full or When fully closed, the ball and seat sealing surface and the dielectric isolation, through the media, will not cause erosion of the valve sealing surface. Ball valve installation and maintenance should note the following:

1) Ball valve handle rotation to leave the position.
2) Cannot be used as a throttle.
3) Ball valve belt transmission mechanism should be installed upright. Ball valve works by the rotary valve love to make the ball valve flow or occlusion. Ball valve switch light, ball valve small size, can be made into a large caliber, reliable sealing, simple structure, easy maintenance, with the spherical sealing surface often in the closed state, the media cannot easily be eroded, in various sectors has been widely used. A ball valve in the pipeline is mainly used for cutting, distribution and changes the direction of media flow. Metal seat ball valve is a relatively new type of ball valve type, it has its own unique structure some advantages, such as switches without friction, seal easy to wear, small opening and closing torque. This reduces the actuator with the specifications. With multi-turn actuators can be realized on media regulation and tight cut. Widely used in urban water supply and drainage in petrochemical demanding cutting conditions.

Should you want to know more about ball valve, such as trunnion ball valves, please visit www.reliavalve.com or email us via sales@reliavalve.com.

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12. September 2015 · Comments Off · Categories: BALL VALVE

Below is the procedure to choose the right V-type ball valves.

1) V-type ball valve selected purposes, the use of working conditions and manipulation control.
2)The nature of the work of the media: work pressure, temperature, corrosion, whether it contains solid particles, the medium is toxic, whether it is flammable, explosive medium, the medium viscosity and so on.
3) V-type ball valve flow characteristics requirements: flow resistance, discharge capacity, flow characteristics, seal level, and so on.
4)The installation size and dimension requirements: nominal diameter, with pipe connections and dimensions, dimensions or weight restrictions.
5) V-type ball valve product reliability, service life and performance, explosion-proof electric apparatus of the appended claims. (Should be selected parameter, Note: If you want to use V-type ball valve control purposes, additional parameters must be determined as follows: methods of operation, the maximum and minimum flow requirements, the normal flow of the pressure drop, pressure drop when closed, and maximum ball must be detailed understanding of the internal structure of the various types of V-type ball valve minimum inlet pressure.) Based on the selection of V-ball basis, reasonable and correct choice of V-ball Shihai, preferred to be able to make a V-type ball valve the right choice. Pipeline is the ultimate control valve. V-type ball valve opening and closing parts of the media stream control mode in the pipeline, the shape of the valve flow path of the valve with a certain flow characteristics in choosing the most suitable piping system V-type ball valve when installed must take this into account.

Should you want to know more about ball valve from Reliable China ball valve manufacturer, please visit www.reliavalve.com or email us via sales@reliavalve.com.

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12. September 2015 · Comments Off · Categories: BALL VALVE

Eccentric half ball valve is made to achieve the opening by rotating the ball around the body centerline, a valve closed. Eccentric semi-ball valve wear (friction ball solve traditional problems), switch light, corrosion (in the fully open fully closed, the ball and seat sealing face isolation, does not produce any friction), easy maintenance, low torque design (using special stem, switch easy and convenient), low cost, suitable to make large diameter, stable performance, reliable sealing, simple structure, easy maintenance, with the spherical sealing surface often in the closed state, not easily be eroded media, eccentric half ball in sewage treatment industries, pulp, aluminum, urban heating, power plants, hydraulic slag or gas pipeline control is widely used, here I will take a hard seal eccentric half ball used in the aluminum industry to it has the advantages described.

Since hard seal eccentric half ball valve as alumina dedicated, had its performance can cut aluminum materials occupy a considerable part of the market, but also exposed the use of trunnion mounted ball valve structure and in the way hard seal force poor sealing performance shortcomings, how to make the sealing performance has improved leaving half-ball half ball alumina industry to improve the utilization of technological valve manufacturer Division title.

1) Semi-ball valve because of its emphasis on the internal structure of the reasons and to ensure that the role of the one-way hard seal, seat support alone is not enough for the hemisphere, the use of high-tech new materials to reduce the weight of the dome, using supersonic spray carbonation Tungsten technology available on lighter hemisphere blank fuss, and reducing the weight of the hemisphere but also to ensure its wear resistance, erosion performance.
2) Increase the strength of the stem seal is one way to solve the problem, half ball hemisphere structure generally used for the U and V are two, is to rely on the axis of rotation to drive close, open; so that the shaft (stem) The flexural strength of the valve seal to do with good or bad play a key must be used easily deformable material processed through the flexural strength guarantee does not bend, or half ball will produce internal stress during use and impact of the valve seal.
3) The hard sealing resilient seat half ball valve can improve sealing performance, the semi-ball valve seat seal structure design will be made into line taken hug seat hole machining or processing methods can dovetail with elastic seat Back to recoil to improve half ball valve sealing performance.

Should you want to know more about ball valve from Reliable China valve manufacturer, please visit www.reliavalve.com or email us via sales@reliavalve.com.

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12. September 2015 · Comments Off · Categories: BALL VALVE

National standards, the United States and European standards are not raised full bore and reduced bore ball valve problem that requires all ball valves are to be pressure drop test, only the standard set forth in Korea: ball valve port inner diameter equal to the inner diameter of less than 85% called reduced diameter valve, ball valve port diameter greater than the inner diameter of 95% referred to the full bore ball valve.

Considering the price, the international community generally defaults, using the same ball diameter adjacent the inner diameter. As DN32 and DN40, DN50 and DN63, DN90 and DN110, DN160 and DN200, DN250 and DN315 using the same sphere. Korean standard has an inner diameter of the ball clearly stipulates: 20A, 25A, 30A, 40A (equivalent to DN25 to DN50), 100A and 125A (equivalent DN110 and DN140), 200A and 250A (equivalent DN200 and DN250) or 250A and 300A (equivalent DN250 and DN315) using the same sphere. Canada JANA laboratory test shows that when the inner diameter of the ball valve port is greater than the inner diameter of the tube for more than 80%, almost no effect on the ability of the fluid through the pipe.
So what occasions to choose the full bore ball valve and reduced bore ball valve? For conveying sticky, easy to knot ball slag medium pipe should use full bore ball valve, convenient regularly purged through scraping wax. For transporting gas or similar physical properties should be used on medium piped water reduced diameter valve, full bore because of the weight ratio of about 30% lighter ball will help reduce pipeline load, reducing costs, but require regular pigging The pipeline, no matter what kind of media delivery, must use full bore ball valve. According API6D standard, ball valves and two reduced diameter ball valve full bore, reduced diameter valves in DN300 and shrink within a specification, DN250-600 shrink two specifications, DN600 above the contract negotiations.

Should you want to know more about ball valve from Reliable China valve manufacturer, please visit www.reliavalve.com or email us via sales@reliavalve.com.

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12. September 2015 · Comments Off · Categories: Strainer

strainer types. There are many forms in accordance with the structure and appearance can be divided into Y type strainers, T-type strainer, basket strainer, etc. Material can be divided into stainless steel Y-strainer, steel Y-type strainers, according to the aperture size can be divided into large-caliber Y-strainer and small-caliber Y-type strainers, etc., how to choose the right strainer it? The following aspects should be considered:

1) The strainer medium of choice.
First, the chemical name in accordance with the fluid to be strainered, depending on the chemical with contraindications to find available strainers, then for its operating temperature, operating pressure, pH, operating conditions (eg, whether the need to withstand steam, hot water or chemical sterilization etc.), individual assessment, and does not apply the strainer removed. Use is also an important consideration, strainer such as medicine, food or cosmetic use of the material must be FDA permitted; ultra-pure water must be pure, does not contain emissions will affect the ratio of the impedance of the strainer; strainer gas shall be selection of hydrophobic material and whether “health level strainer” design and so on.

2) To determine the accuracy of strainers.
This is one of the most vexing problems. For example, to remove visible particles, to use 25 micron strainer; to remove the liquid cloud-like, to use 1 or 5 micron strainer; you need to strainer out the smallest bacterial 0.2 micron strainer. The problem is that there are two filtration units precision: absolute precision / nominal accuracy
Absolute accuracy is the particle strainer out 100% of the accuracy of a label. Any kind of strainer, this is almost an impossible and impractical, since 100% is a infinite value. The market known as absolute strainers such as films, etc., strictly speaking, can only be called “close to absolute” strainers, while others belong to the nominal accuracy, nominal accuracy, this is the main trouble lies: “Nominal Accuracy We do not have a common recognized and executable standard. ” That A company can be set at a nominal accuracy of 85-95%, while Company B would rather set at 50-70%. In other words, a company of 25-micron strainer accuracy of Company B may be equal to 5 microns, or finer. On this issue, experienced professional strainer supplier can help the most suitable strainer, but the fundamental solution is to “try.”

3)According to the temperature at which the viscosity of the strainer, professional strainer equipment suppliers can calculate the size of the strainer, the number of branch strainer installed, each cartridge can bear, and predict a flow rate of primary pressure drop. If it can provide a fluid impurities, and even estimated life.
4) Filtration system of design.

This may involve a wider scope, such as the selection of a pressure source, how much pressure to apply the strainer life completely, whether two sets of strainers in parallel, to fit the continuity of the operation of the system, for a wide particle size distribution How should the occasion with a coarse strainer and fine strainer, the system whether check valve or other devices, and so on. These require the use of units with strainer suppliers worked together to identify the most appropriate design.

Should you want to know more about strainer from Reliable China ball valve manufacturer, please visit www.reliavalve.com or email us via sales@reliavalve.com.

 

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