Fluoramide 1, high temperature can not be used, it is very prone to phytotoxicity. 2, the general effect on downy mildew. 3, can not be combined with emulsifiable oil, because the permeability is very good, and after the emulsified oil, there will be blade deformity, curling. 4, sensitive to melons, easy to produce phytotoxicity. Leafy vegetables are also not used as much as possible. 5, the most important point, the manufacturer's medication matters actually have the following words: do not apply drugs in plastic facilities. Second, pyrimethanil The substance of pyrimethanil is very very very sensitive to temperature. My feeling is that it is more than 25 degrees, which is particularly apt to cause phytotoxicity. Beans and eggplant can be used without it, no, it is best not to use it. It is especially easy to spot. Symptoms of phytotoxicity at high temperatures: 1. After the eggplant is applied, the leaves appear dark brown spots. 2. After the cucumber is used, there is a chlorotic plaque. Severe blade burning, whitening. 3. The beans are dried directly, like a herbicide . 4, the tomato may have yellowing of the leaf margin. 5, cherries do not want to use, spray once, three years of white dry. Just a little, this thing has a low temperature, no phytotoxicity, and a high temperature is a madman. Third, procymidone Procymidone is a common drug for our prevention and treatment of gray mold, and the safety factor is very, very high. However, this product has been tainted. I used 80% water-dispersed granules for this medicine. I remember the medicinal damage. On the cabbage, the old leaves appeared white spots. After four or five days, the leaves began to yellow, and the growth of cabbage was inhibited. The cabbage in the core period stops the heart, and many people may not believe that there will be phytotoxicity, but it is out, and this year, once again, it is still on the cabbage, still using 80% water-dispersing particles. It is recommended that this medicine be used sparingly on cabbage, especially the vigorous growth of cabbage. Fourth, metalaxyl Metalaxyl, do not say this medicine spray, spray this medicine has no effect. Drug resistance is there. Metalaxe is often used in places where beans and peppers are grown. It is not used for spraying. It is used to root, to prevent root rot and stem-based rot of Phytophthora. This medicine does not look at the spray effect, and the rooting effect is gray, which makes full use of the system's systemic and conductive properties. Many agricultural stores use this medicine as a secret recipe to root. However, however, if a bucket of water is more than 25 grams and the roots are less than 300, it is very prone to yellow heads, stop growing, and it will not grow or grow slowly for nearly a month. Many people eat here. Loss. Be sure to pay attention and pay attention. Five, chlorpyrifos Not to mention the effect of this drug on other insects, the quick-acting effect of this drug on Red Spider is unparalleled. However, however, if the drug is once hot, and the concentration of the drug is too large and it is easy to damage the leaves, it causes yellowing and premature aging of the leaves. The most important thing is that this medicine is very easy to spot on the big dragon long eggplant, like a pockmark. Therefore, you must pay attention to the temperature, the concentration of the drug, and the time of spraying. Rational use of the drug will produce a god-like effect on the spider. However, this drug has been listed as highly toxic this year and will not be used. such a pity. Six, Fumei double Fumeishuang I think that many people are too lazy to use it, but I have to explain that it is very important that if this medicine is used reasonably, it will have a great effect on Sclerotinia. However, with this old medicine, the medicine that is too lazy to use is also harmful. On the tomato, it is easy to appear dry tip and specialize in young leaves. Appear once at a time. But when the sclerotinia disease breaks out, you don't have to, but the tomatoes on our side will top. Will not affect too much. Seven, lycopene copper In the past two years, the drug has been raised, and the family said it is safe and very safe. It is true that this drug is safe enough, but this drug has a fatal flaw. It sprays on the eggplant leaves and sprays in the afternoon. On the second day, the leaves appear wilted and gradually return to normal on the third day. However, this problem has caused me to lose a few big customers. The understanding of the peasants is wilting, which will affect the growth and affect the output. However, the effect of this drug on the bacterial spot effect of eggplant is much better than other copper preparations. I don't understand what this principle is. Eight, glyphosate Glyphosate, a herbicide, is enough for cattle, but it has weaknesses, just like any martial arts kung fu, there are flaws. The weakness of glyphosate is that low temperature does not die. So at low temperatures, don't sell this product. Farmers think that glyphosate will kill the grass. If it doesn't die, it is a fake drug. Therefore, weeding with this product at low temperatures makes it easy to earn a reputation for selling fake drugs. Nine, acetamiprid The acetamiprid, the common medicine for mites, is very familiar, but this medicine has a defect. I don't know if it is written or not written in the manual. This medicine is sensitive to temperature, high temperature and good insecticidal effect. The temperature is low, and the effect is not lost. It doesn't matter in the shed, you can pay attention to the temperature of the medicine in the open air. A ball check valve is a check valve in which the closing member, the movable part to block the flow, is a spherical ball. In some ball check Valves, the ball is spring-loaded to help keep it shut. For those designs without a spring, reverse flow is required to move the ball toward the seat and create a seal. The interior surface of the main seats of ball check valves are more or less conically-tapered to guide the ball into the seat and form a positive seal when stopping reverse flow. Check Valves, Water Check Valves, Brass Check Valves, Sanitary Check Valves ZHEJIANG KINGSIR VALVE CO., LTD. , https://www.kingsir-valve.com
Ball check valves are often very small, simple, and cheap. They are commonly used in liquid or gel minipump dispenser spigots, spray devices, some rubber bulbs for pumping air, etc., manual air pumps and some other pumps, and refillable dispensing syringes. Although the balls are most often made of metal, they can be made of other materials, or in some specialized cases out of artificial ruby. High pressure HPLC pumps and similar applications commonly use small inlet and outlet ball check valves with both balls and seats made of artificial ruby, for both hardness and chemical resistance. After prolonged use, such check valves can eventually wear out or the seat can develop a crack, requiring replacement. Therefore, such valves are made to be replaceable, sometimes placed in a small plastic body tightly-fitted inside a metal fitting which can withstand high pressure and which is screwed into the pump head.
There are similar check valves where the disc is not a ball, but some other shape, such as a poppet energized by a spring. Ball check valves should not be confused with Ball Valves, which is a different type of valve in which a ball acts as a controllable rotor to stop or direct flow.
A diaphragm check valve uses a flexing rubber diaphragm positioned to create a normally-closed valve. Pressure on the upstream side must be greater than the pressure on the downstream side by a certain amount, known as the pressure differential, for the check valve to open allowing flow. Once positive pressure stops, the diaphragm automatically flexes back to its original closed position.
A swing check valve or tilting disc check valve is check valve in which the disc, the movable part to block the flow, swings on a hinge or trunnion, either onto the seat to block reverse flow or off the seat to allow forward flow. The seat opening cross-section may be perpendicular to the centerline between the two ports or at an angle. Although swing check valves can come in various sizes, large check valves are often swing check valves. The flapper valve in a flush-toilet mechanism is an example of this type of valve. Tank pressure holding it closed is overcome by manual lift of the flapper. It then remains open until the tank Drains and the flapper falls due to gravity. Another variation of this mechanism is the clapper valve, used in applications such firefighting and fire life safety systems. A hinged gate only remains open in the inflowing direction. The clapper valve often also has a spring that keeps the gate shut when there is no forward pressure. Another example is the backwater valve (for sanitary drainage system) that protects against flooding caused by return flow of sewage waters. Such risk occurs most often in sanitary drainage systems connected to combined sewerage systems and in rainwater drainage systems. It may be caused by intense rainfall, thaw or flood.
A stop-check valve is a check valve with override control to stop flow regardless of flow direction or pressure. In addition to closing in response to backflow or insufficient forward pressure (normal check-valve behavior), it can also be deliberately shut by an external mechanism, thereby preventing any flow regardless of forward pressure.
A lift-check valve is a check valve in which the disc, sometimes called a lift, can be lifted up off its seat by higher pressure of inlet or upstream fluid to allow flow to the outlet or downstream side. A guide keeps motion of the disc on a vertical line, so the valve can later reseat properly. When the pressure is no longer higher, gravity or higher downstream pressure will cause the disc to lower onto its seat, shutting the valve to stop reverse flow.
An in-line check valve is a check valve similar to the lift check valve. However, this valve generally has a spring that will 'lift' when there is pressure on the upstream side of the valve. The pressure needed on the upstream side of the valve to overcome the spring tension is called the 'cracking pressure'. When the pressure going through the valve goes below the cracking pressure, the spring will close the valve to prevent back-flow in the process.
A duckbill valve is a check valve in which flow proceeds through a soft tube that protrudes into the downstream side. Back-pressure collapses this tube, cutting off flow.
A pneumatic non-return valve.
Multiple check valves can be connected in series. For example, a double check valve is often used as a backflow prevention device to keep potentially contaminated water from siphoning back into municipal water supply lines. There are also double ball check valves in which there are two ball/seat combinations sequentially in the same body to ensure positive leak-tight shutoff when blocking reverse flow; and piston check valves, wafer check valves, and ball-and-cone check valves.