2016年7月31日星期日

What is the discharge ball valve?

Discharge ball valve is a sphere with a circular passage for opening and closing pieces, turning ball with stem to realize the opening and closing movement of the valve, the opening and closing member is a porous sphere around the vertical axis of rotation in the channel, so as to achieve The purpose of opening and closing the channel. Discharge ball valve is a special structure of valve seat and the end face of the flange from the past, stranded less material, compact structure, excellent sealing performance for the chemical, pharmaceutical, chemical industry 11:50, also be used in particulate media valuables delivery. Use PPL sealing materials, more wear, toothpaste industry vacuum system cream pot discharge the best products.
As a function of the discharge valve in the reactor, at the bottom of tanks and other containers discharge, discharge, sampling, and no dead zone off the operating device. By means of a valve at the bottom of the flange welded to the bottom of the tank and other containers, thus eliminating the phenomenon of residual process medium is usually in the container export, discharge valve according to actual needs, put a flat bottom design type, V-shaped body and provides two modes of operation for lifting and lowering valve (which we called on Expansion and lower development type). Discharge valve performance and use: easy to operate, open free, flexible and reliable motion; simple valve assembly and maintenance, sealing reasonable structure, convenient and practical seal replacement. Structure: The main valve body, valve, seal, stem, frame, valve gland, hand wheels, flanges, nuts, screws and other parts. This type valve in the pipe should generally be installed horizontally.
Discharge valve in the use of relatively simple, according to operating conditions (pressure, medium, temperature, installation location, etc.) and various structural characteristics of the discharge valve, and select the appropriate discharge valve, and its mode of operation.
Should you want to know more about ball valve, such as trunnion ball valve from Reliable China valve manufacturer, please visit www.reliavalve.com or email us via sales@reliavalve.com.

What is the difference between the O-ring ball valve and ordinary ball valve?

O-ring ball valve with floating or fixed design(called trunnion ball valve), the relative motion parts are very small coefficient of friction self-lubricating material, thus operating a small torque, in addition to long-term sealing sealing grease, making the operation more flexible, O-ring ball valve can play the role of regulation and cutting , commonly used in the two control that flow path is simple, fully formed straight channel fully open, the pressure loss is minimal, especially for high viscosity, suspension, pulp and other fluids occasion, reliable sealing, leakage small, soft seal Ball can achieve bubble tight. The differences between O-ring ball valves and ordinary ball valves are as follows:
1)Fluid resistance for the O-ring ball valve.
Ball valve generally has the full bore and reduce bore,the two structures, no matter what the structure, flow resistance coefficient ball valves are relatively small. Conventional valve is a straight-through, also known as full-flow type valve, the channel diameter is equal to the pipe diameter, resistance loss only if an equal length of the pipe friction resistance. In all ball valve valves, fluid resistance O-ring ball valve is minimal. A decrease in the resistance of the pipe system in two ways: First, reduce the fluid flow rate, would be to increase the diameter and the valve size, which will greatly increase the cost of piping system. The second is to reduce the valve local resistance, O-ball valve is the best choice.
2)The switch quickly and easily for the O-ring ball valve.
O-ring ball valve just rotated 90 degrees to complete the fully open or fully closed, it can quickly opened and closed.
3)Good sealing performance for the O-ring ball valve.
O-ring ball valve seats vast majority are using PTFE (PTFE) and other manufacturing an elastic material, commonly referred to as soft seal valve. Soft seal valve has good sealing performance, and the sealing valve surface roughness and precision requirements are not high.
4)Long life for the O-ring ball valve.
Since polytetrafluoroethylene (PTFE or F4) have good self-lubricating, low coefficient of friction with the ball. Due to the improved process reduces the roughness of the ball, thus greatly improving the life of the ball valve.
5)High reliability for the O-ring ball valve.
(1) Ball and a pair of sealing seat will not scratch occur, sharp wear and other faults;
(2)Be changed to stem a built-in, eliminating the stem under fluid pressure may be due to the packing gland Loosen flying accidents;
(3) Anti-static, ball refractory structure can be used to transport oil, natural gas, coal gas pipeline.
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The common structure of V notch ball valves

Commonly used V notch ball valve connection type flange end V notch ball valve and wafer V notch ball valve , seal type soft seated V notch ball valve and metal seated V notch ball valve.
V notch ball valve is generally made of carbon steel or stainless steel casting, there are some ceramic sintering, but the high cost of the ceramic body and not easy to process, so in addition to those for corrosion and wear particularly demanding situations, generally have little use. O-type ball valve general assembly in order to facilitate trim and valve body into several parts good, but V notch ball valve inner parts, especially the ball valve core is smaller than O-type ball valve is relatively easy to assemble; it is generally We have adopted the unitary body.
V notch ball valve stem in the ball core separates into two sections. The stem is connected to the actuator, the actuator will transmit the rotation of the ball core, controls the opening of V notch ball valve, inserted by the stuffing box installation. The lower stem only from the role of a shaft, which is fixed to the axis of rotation of the spherical core, the installation is generally from the bottom of the body of the insert, and then compress the seal under the cap.
V notch ball valve ball core as part of a sphere, the sphere has a V-shaped notch. Different angular stroke V-notch corresponding to different sizes, different flow area, thereby controlling the flow of fluid. V notch ball valve flow characteristics are generally equal percentage flow characteristics. Edge V-notch is more sharp, with cut feature, you can cut off the fluid inclusions of fiber, so closely with the sealing surface. V notch ball valve ball core typically designed eccentric rotation. Eccentric design, the off time between the ball and the seat are certain core clamping force, is more reliable seal; when you open V notch ball valve ball core can be quickly removed from the seat, reducing the ball core with the valve seat between the friction and wear, to ensure close coordination of the two, extending the service life of V-ball. Sealing surface of the V notch ball valve ball cores generally have been special treatment, the use of high temperature nickel-based alloys or tungsten-cobalt alloy and other hard material at the surface, thus reducing wear and prolong life.
V notch ball valve points soft seal and hard seal (also called metal seated ball valve).  During installation, the general seat by a runner into the back and tighten the retainer, a spring between them to prevent loosening. Soft sealing seat in the front seat bracket by pressing the seat retainer bracket to be fixed. Hard seal seat 316 is often used as a base, and then in the vicinity of the sealing surface of surfacing tungsten carbide cobalt chrome to reduce the wear and tear; soft sealing valve is commonly used molybdenum disulphide reinforced polytetrafluoroethylene. You can use an elastic hard sealed seat at high temperatures, with a small amount of plastic deformation at high temperatures to fix the valve seat due to expansion valve stuck ball core issues.
V notch ball valve of stuffing and other parts of the control valve and is not much difference compared to conventional fillers generally are PTFE asbestos, flexible graphite and the like.
Assembly repair should take care to protect the finished surface of the core V-ball ball on the seat, ensure concentricity between the spherical core and the valve seat. Consistent with the direction of fluid flow in the direction of flow indicated by signs installation.
Common V notch ball valve is mainly made up of body, up and down the stem, ball core, seat components, packing components, and some other component parts.
Should you want to know more about ball valve, such as trunnion ball valve from Reliable China valve manufacturer, please visit www.reliavalve.com or email us via sales@reliavalve.com.
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The application of v notch ball valves

V type ball valve is a fixed ball, it is widely used to control chemical, power, textile, food, pharmaceutical, paper and other industries in fiber type, slurry type and other types of fluid for pressure rating PN16 ~ PN64 ( Class150 ~ Class300), soft sealing valve V-type seal with no leakage, hard seal seal level can also be reached Level IV. Like other ball valve, V-type ball valve movement pattern is rotated, with the straight travel valve can overcome the greater the pressure difference compared to the maximum pressure is generally 2.5 to 10 times straight trip valve.
V-type ball valve depending on the application, V-type ball valve can be divided into shut-off valve, regulating valve. Sealing well as cut-off valve. You can replace the O-type ball or gate, as the regulator, good runner simple circulation characteristics, and V-notch ball on the core can ensure the flow characteristics of a small opening when compared with straight-through valve higher Adjustable ratio (300: 1). Since the flow path is simple, small flow resistance, when the flow of the pressure on both sides of the body is also smaller, more suitable prone to cavitation cavitation occasions.
Should you want to know more about ball valve, such as metal seated ball valve from Reliable China valve manufacturer, please visit www.reliavalve.com or email us via sales@reliavalve.com.
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Structure and Benefits Feature of Fully Welded Ball Valves

Fully welded ball valve body consists of six parts of the back cover off the assembly forged welded, compact, fully welded ball valve as one whole, there are many manufacturers of large diameter ball used mostly split three-piece construction, between the parts with bolts. Compared with the three-valve, in the case of the same intensity forging thickness welded ball valve can be made thin. Reduce the weight of the valve a quarter, and the pipeline increased resistance to bending and squeezing; by eliminating the body flange and bolts, reduced dimensions, but also eliminates a potential leak path, in addition, the valve body welded internal structure smooth curves, maintaining lubrication and pipe connections, no dead ends, medium fluidity. The main advantage of feature fully welded ball valve as follows:
1) Integral fully welded ball valve, there will be no external leakage and so on.
2) Since the fully welded ball valve seat is carbonized and added Teflon sealing ring springs, so that changes in pressure and temperature adaptability, in marked pressure and temperature range will not produce any discharge slip.
3) Fully welded ball valve Processing sphere detector with advanced computer tracking and detection, so the sphere of precision.
4) The fully welded ball valve body material with pipe material, it would not appear uneven stress, it will not go through because of the earthquake and ground vehicles and sometimes deformed, anti-aging pipelines.
5)The seal ring body with content 25% Carbon (carbon) in CPTFE material, will guarantee completely leak (0%).
6 Buried welded ball valve can be directly buried in the ground, do not build high large valve well, just set up a small shallow in the ground, saving construction costs and engineering time.
7) According to the construction and design requirements of piping, all-welded ball valve to adjust the height and length of the stem.
8) Fully welded ball valve ball very precise machining precision, easy operation, no adverse interference.
9) Use of advanced materials, energy security than PN25 pressure.
10) Compared with the same industry, the same kinds of product specifications, all-welded ball valve is small, and good looks.
11) In ensuring the normal operation of the valve, use, the fully welded ball valve factory warranty of 20 years.
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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2016年7月27日星期三

Eccentric hemisphere ball valve of air tightness test

Eccentric hemisphere ball valve of air tightness test is divided into eccentric half ball to remove air tightness test and eccentric half ball line tightness test, are described below:
First, the eccentric hemisphere ball valve detached air tightness test
(1) The eccentric hemisphere ball valve in a semi-open state, both ends of the ball with pipe connection flange lid seal.
(2) To the end of the introduction of test medium, test medium for clean nitrogen or air, and the other end of the pipe joint block, gradually pressurized to 5.6bar close the inlet valve to stop the intake.
(3)The ball is rotated several times after the eccentric hemisphere ball valve off (operation of the drive means)
(4) Open the other end (non-introduction of test gas side) pipe fittings plug so that the chamber pressure is reduced to atmospheric pressure.
(5) At the test pressure (5.6bar), larger than 5min time, the intake chamber pressure shall not decline, the pressure gauge should be 0.4, range 10bar.
(6) At the same time eccentric hemisphere ball valve with soapy water to check each connecting flange portion and a filler portion of the external leak, without increasing the bubbles appear.
(7) The test medium is then introduced from the other side and repeat the test.
(8) After passing the test with compressed air blowing soap residue, demolition ends flange cover, remove the sealing surface of the eccentric half ball seal both ends of the residue, if any residue into the valve hole should be removed and cleaned.
Secondly, the eccentric half ball line tightness test
(1) Identify the subjects eccentric half ball valve, cut-off valve downstream is closed.
(2)To be tested in a semi-eccentric half ball open.
(3) To be tested before the introduction pipe eccentric half ball test medium, test medium for clean pressurized nitrogen to 5.6bar gradually close the inlet valve to stop the intake.
(4)The ball is rotated several times after the eccentric half ball valve is closed (operating the drive means).
(5) Open purge valve was tested eccentric half ball valve downstream of the outlet pipe so that the chamber pressure is atmospheric.
(6) At the test pressure (5.6bar), more than 15min time pressure must not fall into the gas chamber, the pressure gauge should be 0.4, range 10bar.
(7) While eccentric hemisphere ball valve with soapy water to check each connecting flange portion and a filler portion of the external leak, without increasing the bubbles appear.
(8) And to be tested eccentric half ball test medium, the test is repeated.
(9) After passing the test with compressed air blowing soap residue.
Tightness test method described above eccentric hemisphere ball valve can be applied to the vast majority of air tightness test.

Within Brush automatic strainer working principle

Brush automatic strainer in the domestic high-quality seamless and welded flange national standard, the machine is divided into coarse strainer and fine strainer two large chambers; with a strainer, sewage components, hydraulic motors and sewage pipes, etc. institutions.
The strainer pipeline belongs fine strainers can be installed vertical horizontal. Filtration system is divided into two, the first stage of the coarse strainer, mesh diameter 0.8mm, the second stage fine strainer, mesh diameter of 0.3mm.
Liquid from the inlet into the strainer, through the outer coarse strainer into the strainer, dirt particle size greater than 0.8mm thick strainer was blocked in the space outside the cavity strainer, wait sewage; within this time the strainer liquid and then by fine strainer flow within the network, but at the same time a diameter greater than 0.3mm dirt is left in the network or adhering to the inner wall of fine mesh; interception and adsorption in the machine of debris more than a certain amount, will inevitably result in over-water area is reduced, thereby pressure poor increase, when the pressure reaches the set value (can adjust the parameters via the HMI), PLC start sewerage program, both electric discharge valve opens at a relatively negative role, hydraulic motor drives the brush along the network (outside) wall motion, and will remain adhered to the brush debris from the machine, and by allowing the mouthpiece, the sewage pipe into the sewage branch in charge, and then through the outer flow hydraulic motors machine; after the discharge time, the electric valve is closed, liquid force motor lost power to stop, end sewage.
Should you want to know more about strainer from Reliable China valve manufacturer, please visit www.reliavalve.com or email us via sales@reliavalve.com.
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What is the application of ceramic ball valves?

Ceramic ball valve because of advanced ceramic materials possess its own high hardness, high strength, high wear resistance and good corrosion resistance, can greatly improve the ball valve corrosion, abrasion, erosion, and high temperature performance, greatly extending the ball of life, thus extending the work cycle, improve work efficiency, saving maintenance costs. During adjustment limestone slurry, gypsum slurry waste water, the ceramic V-type ball valve is the best ball is the best substitute for imported products, with a high promotional value.
Ceramic ball valve is mainly used in power plants, iron and steel, petroleum, chemical, paper, bio-engineering, and other industries, for boiler steam, stone mortar, including sea transport particles, high hardness particle containing soft particles and corrosive media, powder , flue gas desulphurization, ash, slag, water treatment. According to use to replace the material that can be used for different temperatures and media, especially in the face of high wear, high corrosion, high temperature, high pressure and other adverse conditions, ceramic ball also demonstrated its superior performance. Ceramic ball valves to meet the high wear, high corrosive environment, especially prominent feature is the long service life of ceramic ball valve performance is far better than other similar metal seated ball valves.  As science and technology continues to evolve and progress, the ceramic material is more mature and complete the recipe, molding, machining and assembly process and other aspects of technology, the company produced its excellent performance ceramic ball valve industry has been more Identity people. The use of the successful experience of the manufacture of ceramic valve can also be applied to a wider range of other areas of the ball valve.

Maximum allowable leakage rate calculation of Flue butterfly valve and metal seated butterfly valve

Flanged and clip closure connection and adjust the flow with the flue butterfly valves are available in nominal pressure ≤PN0.6MPa, nominal diameter ≤DN3000mm, temperature ≤450 ℃, the medium is air, flue gas dust and gas and other industries.
Flue butterfly valve is suitable for adjusting the flow rate within the specified range and the closure.Flue butterfly valve compared with metal seal butterfly valve, butterfly valve in the conditions of use, structure and technical requirements, and leak rate test and test methods are different.
Metal seal butterfly valve minimum standard E-class gas maximum allowable leak rate: 200 × DN (mm3 / s).
Butterfly valve highest standards of A-level flue gas maximum allowable leak rate: L 0 = K × DN2 × √P × 10-6
Where L 0 --- maximum allowable leakage rate, Nm3 / h.
K --- A level leak factor
DN --- butterfly valve nominal diameter, mm
P --- test pressure, MPa.
From the above analysis standards and formulas, flue butterfly valve A level leak rate significantly higher than standard metal seal butterfly valve leak rate E-class standards. In the butterfly valve DN1200 caliber, for example, metal seal butterfly E-class standard maximum allowable leak rate
200 × DN = 200 × 1200
= 240 000mm 2 / s
= 0.014 4m3 / min
A level standard flue butterfly maximum allowable leak rate (according to 0.6MPa Nominal)
L0 = K × DN2 × √P × 10- 6
= 7.3 × 12002 × √600 000 × 10 - 6
= 8143Nm3 / h
= 136Nm3 / min
Analysis by the formula, flue butterfly valve and metal seal butterfly valve on the structural design and test methods are different, the flue butterfly valve sealing requirements significantly lower metal seal butterfly valve, its regulation characteristics similar to metal seal butterfly valve.
What are the technical requirements of the flue gas butterfly valves?
Flue gas butterfly valve flange dimensions, the sealing surface in the form of both ends of the flange bolt holes d0 axis with respect to the flange of the position tolerance, the minimum length of the structure and the valve seat diameter bore axis is to follow certain standards and technical requirements.
Flue gas butterfly valve flange dimensions and sealing surface in the form of regulations according to API609, and flue gas butterfly valve flange sealing surface should be perpendicular to the channel axis, coaxial with the axis should smoke butterfly valve channel, flange sealing surface should be parallel to each other at both ends of its axis its parallelism by API609 accuracy, connecting flange structure according to the need to allow the bolt hole threaded flange bolt holes at both ends of the axis relative to the flange d0 position tolerance bore axis as defined, the flange connecting flue gas butterfly valve structural length required to API609, and to connect the flue gas butterfly valve clip length of the structure in accordance with the provisions of API609, the nominal diameter of 2000 mm greater than the length of the flue gas butterfly valve structure according to user requirements to determine the seat of the minimum diameter It shall not be less than the specified.
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.

2016年7月26日星期二

Plastic ball valve welding step

Plastic ball valve soldering should follow certain steps should first be carried out step by step to prepare pipes, fused sleeve, welding machines and other auxiliary tools such as cutters, scrapers, white marker, ruler etc; ready to 220V AC power; press Good to be welded need to cut the pipe length; the pipe insertion portion amount of half the length of the sleeve, with a white marker as a ring mark, then draw on the surface of the distribution between the mark and the pipe end of uniform helix; or with a hand scraper There are rotating blades scraping the entire surface oxide within marked area, and remove debris; good scratch pipe surface must not touch any dirt or contamination; Note: The cleaned after pipe scale should be placed after a long re clean up the scale, and then follow the steps below to plastic ball welding operation:
1) Open the package take out fused sleeve, it would have been a good blow pipe is inserted into the sleeve of two;
2) Insert the depth of mark or two pipe ends are fixed to the inner sleeve against the ring as a standard;
3) Must take all measures to ensure that the two pipe axis and the axis of the sleeve in a straight line;
4) Fused welder output plug plugged into the sleeve;
5) Turn on the power fused welder, turn on the switch;
6) Press the scanner switch button with a bar code scanner sweep read sleeve;
7) Click the "Start" button, automatic welder start welding;
8) The time to be welded, welder automatic alarm and stop welding, press the "reset" button to close the welder switch;
9) Unplug output plug, cover dust cap, cooled to a predetermined time;
Plastic ball valve welding process, non-moving pipe fittings until the cooling time after the end of the countdown, into the cooling stage, according to the tube marked cooling time for cooling, NOTE: During the cooling process non-mobile welding fittings; fittings should be cooled in the natural state .
Should you want to know more about ball  valves from China valve manufacturer, please feel free to visit www.reliavalve.com or send us email to sales@reliavalve.com.

What matters should pay attention to for the eccentric semi-ball valve maintenance?

Eccentric semi-ball valve course inevitably there will be some small problems, if the problem is not you can do it yourself repair them, province to find valve manufacturers, pending repairs tedious process, here are a little eccentric half ball Matters maintenance should pay attention to, and we hope that we can help.
1)Must be identified on the eccentric semi-ball valve, after removing the pressure downstream pipeline has indeed to be demolished decomposition operation.
2) Must be taken to prevent damage to the parts of the sealing surface decomposition and re-assembly, especially when the non-metallic parts, O-rings should be taken when using special tools.
3) When the mounting bolts on the flange must be symmetrical, gradually and evenly tightened.
4) The cleaning agent should be compatible with the eccentric half ball rubber parts, plastic parts, metal parts and the working medium (such as gas) are. Working medium for the gas, available gasoline (API6D) to clean metal parts, non-metallic parts cleaning with pure water or alcohol.
5) Exploded down the individual parts can be cleaned by immersion mode, yet left down decomposition of non-metallic parts of the metal parts can be impregnated with fine Jie clean cleaning agent of silk (to avoid fiber loss adhered parts a) scrubbing shall adhere to the wall surface to remove all grease, dirt, rubber, dust and so on.
6) Non-metallic parts should be cleaned immediately after removal from the cleaning agent, not a long soak.
7) After cleaning the wall needed to be to be washed after volatile cleaning agent (not soaked cleaning agent available silk rub) for assembly, but not for a long time on hold, otherwise it will rust, dust pollution.
8) The new parts in the assembly also need clean water.
9) With grease lubrication, grease should all be compatible with the eccentric semi-ball valve of metal materials, rubber parts, plastic parts and the working medium. Working medium for the gas, can be used such as 221 special grease on the surface of the seal mounting groove is coated with a thin layer of grease, spread a thin layer of grease on the rubber seals, valve stem sealing surface and the friction surface coating a thin layer of grease.
10)The assembly should not allow metal fragments, fiber, fat (except the requirement to use) dust and other impurities and foreign matter contamination, adhere to or remain on the part surface or into the cavity.
Should you want to know more about ball valve, such as trunnion ball valve from Relia Valve, please visit www.reliavalve.com or send email to sales@reliavalve.com.
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V-type ball valve in the regulation System

Recently, a chemical plant of the user phone call asking, conditioning system in their plant equipment using the original valve seat, no 3.8MPa steam, adjust the system is stable; increase 3.8MPa steam, the steam turbine coupled with the opening stop, original valve cannot meet the requirements, in particular in:
1) V-type ball valve leakage volume, closed lax, resulting in valve in a small opening, poor regulation characteristics.
2) V-type ball valve body vibration, noise is high.
3) V-ball valve fluid flow rate is high, the long-term erosion of the V-type ball valve stem up and down vibration severe, resulting in the stem and the valve plug Disconnect, a direct result of the steam cannot pass valve.
In order to solve the above problems, a technician to the site to view and analyze the process conditions and the characteristics of various types of  V-type ball valve, and finally decided to replace the original V-type ball valve seat, valve seat suited to use in the above case because the channel complex, large flow resistance, a small adjustable range; stem up and down movement of the spool poor stability, vibration. V-type ball valve stroke than a straight valve has great advantages which is composed of V-type ball valve structure decisions, V-type ball valve spool eccentric structure in the structure, in addition to the closed position, the core seat does not touch the remaining positions, reducing the wear and tear, the valve once opened to disengage the seat, reducing the operating torque, while the spool exclusive V-shaped opening may well ensure that the valve regulating performance in a small opening to solve the linear actuator valve in a small opening operating characteristics of a bad problem, V-type ball valve flow path is simple, straight-through single, small flow resistance, large tuning range, flow-open valve pressure recovery coefficient is higher than the valve seat is more applicable to the case of the occurrence of cavitation , V-type spool valve stem movement of rotation and linear movement of the valve compared to overcome the large pressure difference, which is 2.5 to 10 times straight trip valve in solving high temperature problems, V-type ball valve just hard soft elastic sealing solutions combine core seat due to hold at high temperature expansion card problem, while using high temperature resistant filler stem to ensure the reliability of sealing at high temperatures.
After a period of proof, V-type ball valve regulating fast response, wide flow range control, basically no vibration, noise is significantly reduced, eliminating the hazards present in the system.
Should you want to know more about ball valve, such as trunnion ball valve from China valve manufacturer, please visit www.reliavalve.com or send email to sales@reliavalve.com.

2016年7月25日星期一

Factors affecting the performance of fully welded ball valve weld shape

Factors Affecting fully welded ball valve weld shape, performance there are many, but the most important for a number of welding parameters and welding conditions, the impact of all-welded ball valve weld shape, the performance of the main welding parameters welding current, arc voltage welding speed, wire diameter, etc., the impact of the valve weld welding conditions mainly weld groove shape, clearance and flux and wire piled high, the tip and the work piece inclination, etc., as we explain in detail below:
First, the impact of fully welded ball valve welding parameters on weld shape, performance
(1) The welding current. When other conditions remain unchanged, deep penetration welding current is proportional to the change in current, melt depth, height and width than inadequate; the current is too large, deep penetration, reinforcement is too large, easy to produce high-temperature cracking.
(2)The arc voltage. It is proportional to the arc voltage and arc length, arc voltage and the same welding current, if the choice of different flux, the arc electric field intensity is different, different arc length. When other conditions remain unchanged, the arc voltage is low, deep penetration, narrow weld width, is easy to produce hot cracks; arc voltage is high, the weld width increases, more than high enough. Submerged arc voltage is adjusted based on the welding current, i.e., the welding current must be to maintain a certain arc welding arc it possible to ensure stable combustion, so the range of variation of the arc voltage is limited.
(3) Welding speed. Welding speed has an impact on the penetration and weld width, usually inversely proportional to the depth of penetration and weld width and weld speed. Welding speed on the weld cross-sectional shape also affect the general welding speed is too small, the molten metal volume, poor weld; welding speed is large, the amount of molten metal inadequate, prone to undercut. The actual welding, in order to increase productivity, improve the welding speed while arc power must increase in order to ensure that the weld quality.
(4) Wire diameter. Welding current, arc voltage and the welding speed is constant, the depth of penetration is inversely related to the wire diameter, but the inverse relationship with the increase and decrease of the current density.
Second, the impact of fully welded ball valve welding conditions on weld form.
(1) The weld groove shape, the gap effect. In other conditions, while increasing the groove depth and width of weld penetration increases, weld width decreased slightly, reinforcement significantly reduced.
(2)The impact of the high flux reactor. High flux reactor shall ensure that the filament buried around the arc, generally 25 ~ 40mm. When using solder bonding or sintering flux, the dry density, high flux reactor higher than the melting flux of 20% to 50%. High Flux Reactor larger weld reinforcement bigger, more shallow penetration.
(3) Wire, dip the tip and the work piece has a greater impact on the weld. In the fully welded ball valve welding process, we should try to ensure that tip, the wire vertical dry surface.
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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How to choose the right strainer?

strainer types. There are many forms in accordance with the structure and appearance can be divided into Y type strainersT-type strainerbasket 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.
Related Products:
Din strainers

How to choose the full bore ball valve and reduced bore 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.
Related Products:
Trunnion Ball Valves

2016年7月19日星期二

Eccentric half ball valves application advantages in the alumina industry.

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.

How to choose the right V-type 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.

What matters should pay attention for the ball valve installation and maintenance?

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.

2016年7月14日星期四

What is the front seal and back seal for the 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.

What is the ball valve sealing performance?

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.

2016年7月11日星期一

What is called the valve kinematic pair?

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 valve manufacturer, please visit www.reliavalve.com or email us via sales@reliavalve.com.

How to solve the low temperature ball valve(cryogenic ball valve) stuck pull fixed the problem?

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.