How to find cavitation and air entrainment

How to know when a system is working with cavitation it ? One way is mounted on the pump inlet side of a vacuum gauge and confirm that the pressure is equal to or higher than the nominal working pressure of the pump .
No cavitation vacuum table found the best way is to listen to the sound of the pump . Pump cavitation occurs emits a high-pitched sounds or screams . Sometimes it is difficult to bearing noise , coupling noise, or noise from nearby distinguish the machine , but can be distinguished empirically .
 Through the failure of the entire system can also be found cavitation and air mixing , for example: More knowledge about Hydraulic tube fittings  fittings Standard Health professionals caSince the pump suction dissatisfaction pump output flow will be reduced. This is enough to make the hydraulic cylinder or hydraulic operation of the motor slows down.Damaged by cavitation control valve , the valve active channel becomes large, the movement speed and time may be allowed .
 System may show " spongy " action , particularly in the case of air into more so. Servo valve, mixed with air or the occurrence of cavitation in fluids will appear larger compressibility, the control circuit reduces the stiffness of the system operator can easily discover this phenomenon.How to find air into it ? Long observation tank level indicator level or number of bubbles on it. Ultimate aim is to put in the mail to separate air from the oil so that air is not sucked into the pump inlet . As mentioned earlier, to find the leakage point and take measures to eliminate it .Mailbox rational structure separated from the oil in the air is very important . Fluid in the tank a longer time of stay is obviously beneficial . Pump inlet and the system back to the oil farther away as possible , with the bulkhead between the two elongated away. It is necessary to set the screen ( Figure 2 ) .

What is cavitation

Cavitation more complicated. As the name suggests , it involves in the liquid of the " hole " or " hollow space " Most of these holes is filled with air , and the air pressure at room temperature and which are dissolved in the liquid . Transparent glass tube still no visible bubbles petroleum oil actually contain about 9% of the dissolved air . At any given temperature, the solubility of air in the oil pressure varies directly with the system (Fig. 1 ) . In the standard atmospheric pressure 2.6Mpa , the fluid containing about 9% of the dissolved air , popular point that air is rushed to the oil and stay there dissolved . Until the pressure is reduced or when the temperature drops ran out . If the atmospheric pressure (2.6Mpa) reduced to half 1.3Mpa), dissolved in 9% of 2.6Mpa air will partly separated. Oil will produce bubbles. If this phenomenon occurs buck suction port of the pump or at the edges of the slide valve , the bubble is called " cavitation ."The solubility of air in the oil . The oil surface pressure of the air dissolved in the oil increases the amount of air is increased. Raising the temperature will further increase the amount of dissolved airIn addition to air , the cavity may also have water vapor. Unless carefully dehydrated oil , no barrel new oil will contain at least a few parts per million of water . To withstand temperature changes in  Hydraulic hose fittings  system used oil generally contains several hundred parts per million of water . The vapor pressure of the water vapor pressure than that of mineral oil thousand times higher . Therefore , at any given vacuum condition , the water will be evaporated and the hole filled with steam .

What is air mixed

Air into a state , in this state, separation bubbles are caught when the pump fluid into the liquid flow . Usually observed with the naked eye can identify the cause. Coerced bubbles may be in the air from a height into the oil return generated when the mailbox , it may be in effect through inhalation of a large group of vortex air generated in the tank when the oil level is too low it will happen whirlpool effect .Sometimes one Hydraulic adapters has quality problems or incorrectly installed seals, or incorrectly assembled fittings will put air into the suction side piping ( oil does not leak ) . When you suspect suction side of the leak , the high viscosity of the oil flooded with these points , the noise emitted by making significant changes in the pump can usually find a leak site . A suction pump issue seems empty aqueous gargling sounds.

Prevent hydraulic oil hole

Fluid cavitation in the hydraulic system is a very serious danger . Some users believe that the hydraulic system cavitation and air entrainment is consent of the word , because both in Hydraulic ferrules  system damage is the same. In fact , air mixed gas point is unrelated two phenomena have different causes and different cancellation method .

Liquid tight industry presents the "three pillars " of the situation

 Hydraulic, pneumatic, seals are an important modern drive technology base member , determines the mechanical product performance, quality and reliability. With the development of science and technology , more modern , high levels of host and major technical equipment , on the basis of the requirements of the higher parts . In recent years through scientific and technological research , technology transfer , technological innovation, Hydraulic tube fittings liquid tight many companies within the industry has formed the scale production, product standards continue to improve product quality significantly improved , the market has been expanding . According to statistics, in 2003 the output value of fluid sealing industry $ 11 billion , especially in hydraulic, pneumatic industry output has ranked first in the developing world .

Detailed use of high pressure hose

The use of high-pressure hose that is, we often say that the use of high-pressure hose . Divided into two main areas of use .First, the coal industryMainly coal industry with tubing hydraulic support hose pipe . In recent years , some coal mine hydraulic support requirements have increased the pressure , some steel braided hose can not meet its performance requirements , requiring use wire wound tubing . Moreover, to prevent the process of mining coal mine dust pollution and improve production safety , increasing coal use tubing varieties, such as coal seam water exploration telescopic tubing sealing device for fully mechanized coal mine coal seam prior to mining water , grouting and other operations. According to reports , the domestic manufacturers have been producing , and after more than a dozen mines trial , can replace similar imported products.Second, the oil industry21st Century China National Offshore Oil Development Strategy proposed the keyAnd shallow offshore oilfield development , so the oil industry in addition to using drilling tubing, tubing vibration , but also requires the use of shallow oil pipeline . Shallow undersea oil pipeline country has produced , but floating or semi- floating type oil tubing and deep seabed oil pipeline still rely on imports. With the Chinese offshore oil development strategy, offshore oil exploitation on the tubing performance requirements will continue toincreasMainly divided into high pressure hose wire wound tubing and high pressure wire braided hose, because the performance of varying intensity . Field of use is also different.High pressure steel wire spiral tubing ( pressure tubing ) Uses: High pressure steel wire reinforced hydraulic  Hydraulic pipe fittings hose is mainly used for hydraulic support mine , oil field development , suitable for construction , lifting and transport , metallurgy, forging , mining equipment , ships, injection molding machinery, agricultural machinery, tools and various industrial sectors mechanization and automation of hydraulic transmission system has a certain pressure ( high pressure ) and temperature based ( such as mineral oil , soluble oil , hydraulic oil , fuel oil , lubricating oil ) and water-based liquids ( such as emulsion , oil-water emulsion , water ) , and transmission fluid , maximum pressure resistance of up to 70-120Mpa.High pressure steel wire braided hose Application: High  Hydraulic hose fittings pressure steel wire reinforced hydraulic hose is mainly used for hydraulic support mine , oil field development , suitable for construction , lifting and transport , metallurgy , forging, mining equipment, ships , injection molding machinery , agricultural machinery, machine tools and various industrial sector mechanization and automation of hydraulic transmission system has a certain pressure and temperature based ( such as mineral oil , soluble oil , hydraulic oil , fuel oil , lubricating oil ) and water-based liquids ( such as emulsion , oil-water emulsion, water ) , etc. and transmission fluid . High pressure steel wire braided hose Operating Temperature : oil -40 ℃ ~ 100 ℃, air -30 ℃ ~ 50 ℃, +80 ℃ water emulsion or less. High pressure steel wire braided hose specifications : DN5mm ~ DN102mm.

Hydraulic hose reinforcing material , which has several

As regards the material and the actual strength of which will depend on the application , but also on the manufacturing process . As mentioned earlier, the hose line or cord can be enhanced knitting , weaving , winding and weaving circle , we can use bias cut or straight cut of fabric wrapped around the roll can also be a combination of both .And are currently used in research and development of materials, including the skeleton . Cotton, nylon, high-strength steel wire , flax , linen , polyester, glass fibers, asbestos and carbon fiber , rayon and polypropylene : , according to conventional , choose from the above varieties reinforcing material to withstand rating of decisive factor.When dealing with those more special fabrics such as polyester and polypropylene , you must be very careful to ensure that the degree of accuracy of heat setting , otherwise the hose vulcanization undue distortion will occur .In the use of polypropylene , it must carefully check vulcanization temperature . Degrees condition , because in many cases, this temperature is very close to the softening point of the substrate . Using such yarn or fabric, the adhesive system is also dedicated necessary to ensure the hose member having various levels and full and satisfactory adhesion .Glass fibers and asbestos fibers have been used for steam hose and other heat-resistant hose . Of course, the wire is also used for such purposes:The emergence of new carbon fiber gum possible applications in the field in the gel , but this new material is  Hydraulic adapters currently high cost . Therefore, except in the last few years outside the aerospace industry , will expand the application ; and carbon fiber on which points are worth noting : For tensile strength for comparison , carbon fiber and glass fiber reinforced material differences less , not even the two has a high tensile and low density values ​​- equivalent to 25% of steel , however . great advantage of the use of carbon fiber is reinforced with this  Hydraulic ferrules dielectric material is high strength steel having a large five or six times greater than that of glass fibers characteristics modulo value , the characteristic tensile modulus as a measure of the load , which can support the weight of the beam without specific yield , so the future trend of the carbon fiber to be used for enhancement of metals and ceramics , and not as a general view of the pure fibrous material : it is the purpose of the hose industry is probably making assemblies and dynamic seal in the hydraulic system ,
Another high-strength , high-cost fibers are chemically aromatic amines polyphenol family , a member of the need for high strength , good heat and chemical resistance of the occasion , has its dedicated purpose. The hose system uses include: heavy-duty engines ( such as tractors and heavy duty diesel vehicle refrigeration and cooling connection pipe ) and subsea wells devices based on the application of water-resistant high-pressure hose and so on.