Amalia Hull Valves May 10th, 2019 - 13:57:51
Another way of cheating customers - to use for the manufacture of shells cheaper metal - zinc. This is also the risk of counterfeiting. valve of zinc has increased brittle and may crack on the mechanical and hydraulic influences. There are ball valves, made from silumin (aluminum alloy). Their reliability is still lower. Savings metal induces dishonest manufacturers to produce the body taps with wall thickness from 1 to 0,5 mm. This is extremely reduces their reliability. (For comparison, the standard valves manufacturers Matca-Norca have a wall thickness of 2 mm).
Cases and Ball Valves in the products of leading manufacturers are made by hot pressing or hot forging. Manufacturers producing fake not spent on buying such technology and its products are manufactured by casting. These products are characterized by an uneven surface of the body, rolls, may have a mixed structure of the material - with aerial shells and, consequently, low reliability. Ball valves (balls) rigged valves are often not made of brass, and of transformer steel, coated or even without it. Steel balls quickly corrode and cease to be leak proof. Failure to invest in the copper alloy brass faucet body makes it suspiciously easy. Steel ball compensates for this lack of weight, masking the presence of thin-wall housing is unacceptable.
It is useful to say how counterfeit valves masquerading as the original. One of the techniques - misspelling the names of famous companies, such as, Bogati instead of Matca-Norca. Formally, this is not fake, because the original brand is not used. There are cases of writing only the names of countries, for example, USA, instead of adopting a made in Italy. The distortion of the famous logo, placing it, for example, not a diamond, but a square or a circle, also serves to confuse the buyer. Evidence of fraud may be the absence of any of the markings required for specific manufacturers. The sale of gas valves, and found such a primitive form of deception, as replacement faucet handles on native yellow - gas (gas valves are more expensive). Price savings may be too high, so choose the ball valves are safer from the range of recognized brands.
This is a valve that plays a major role in many areas of industry, including instrumentation and flow control processes. The operational environments will, on occasions, be offshore in extreme, adverse conditions such as oil and gas exploration and extraction processes. The quality and reliability of a manual pinch valve is something that can make a significant difference to an application of this nature.
Now you're probably wondering how instrument makers know how much tubing to add so that the pitch is lowered by half step. And if you're not, I'm still going to explain it! Because of acoustical theory, to lower the pitch by a half step, the working length of the instrument must increase by about 1/15, or 6.67% of the working length. For explanation purposes I will be using an instrument which is 100 inches in length (which is actually close to length of a euphonium). This means the second valve should have a length of 100/15 or 6.67" in order to lower the pitch by one half step. Now, to lower it a half step past that you must add 106.67/15 or 7.11" so the first valve must have a length of 6.67"+7.11" or 13.77 inches. Now let me explain that last statement as it may have thrown some of you off. The reason the first valve would not be simply 2(6.67) is that in order to lower the pitch by a whole step, there must be enough tubing to lower the pitch by a half step (6.67") and then enough tubing to lower that pitch a half step (7.11"). This same theory goes for the third valve, and yields a length of 21.36 inches.
As sleeved valves, then the passport MTBF of 1,300 cycles, their actual performance is enough for 20-40 cycles, after which the sediment accumulated on the sealing saddle, do not allow completely block the flow by turning the valve itself in another "architectural extravagances." Moreover, the coefficient of local resistance they simply record - from 16 to 20. That is, at a flow rate of 1 m / sec, passing through the valve, the pressure of the liquid is reduced by 1 m of water.