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.
Marketing is the way: the furniture industry must be good at creating concepts and more brave to ask questions.
At the end of the year, the concept of the furniture industry has been hyped up and down. For example, “Fengyun Peopleâ€, “Top Tenâ€, “Headquarters Baseâ€, “Brand Upgradeâ€, CBD, etc., it’s a bit dazzling. This is a time of concept marketing, and the furniture industry is no exception. Especially in the context of the current economic crisis, manufacturing depression, and "confidence is more important than gold," the concept is particularly important. Even though many of the current concepts are still in the stage of creativity, experimentation, and speculation, and even some concepts may never be in the air, they can't land, but they provide people with a space of hope. Moreover, as the smallest unit of thinking, the introduction of a new concept also represents a new kind of thinking, which indicates a new possibility and stimulates a positive act. However, many concepts are often born in response to specific problems in specific contexts. If you can't face the problem and get rid of the research on the problem, it is likely to become a falsified, "hanging, selling dog" type of "pseudo" Concept, or boring hype. Unfortunately, the furniture industry is currently immersed in this bad atmosphere: some so-called “fighting people†may just earn some money, and have not done anything really “fightingâ€, let alone people from it. “Fengyun†tastes the rational law of enterprise operation and wealth creation; some so-called “top ten brands†can't talk about how many unique consumer value creations, or they can't talk about brands at the consumer fees. More so, the so-called "headquarters base" advocated by certain regions and enterprises has become a mysterious and mysterious gimmick because it has intentionally or unconsciously ignored many hypothetical premise. In view of this, the author believes that the furniture industry must be good at creating people, but also more people who are brave, good at asking questions and facing problems. Especially in the context of the current escalation of the furniture industry, as Einstein said, "Proposing a problem is more important than solving a problem." The concept must be accompanied by more questions and face up to them. In this way, the concept will not be empty, lack of material meaning, and will be more constructive. In fact, looking around the furniture industry's surrounding environment, we need to raise, face, and think constantly: First, take the problems in the concepts created above. For example, the so-called "Top Ten People" can at least not be engaged in pure buying and selling, zero-sum or even negative-sounding businessmen, but entrepreneurs who participate in certain value creation and positive-neighbor games. How many of these “people in the storm†are pure businessmen, and how many are real entrepreneurs? If they are entrepreneurs, what creative activities did they do? What kind of background did these activities make? In making wise decisions in these contexts, what are the valuable qualities of the “Fengyun People†subject and what difficult choices are made beyond the meaning of ordinary people? Another example is the “Headquarters Baseâ€, which requires the support of many high-end production factors and management elements, such as High-end talents, standardized intellectual property system, excellent living environment, humanistic environment, etc., is there a region that advocates this concept? If not, how to break through these “bottlenecksâ€? What problems will be encountered when breaking through the “bottleneckâ€? If it is a systemic problem, where is the most important breakthrough at present?... Our "problem" is actually still Can be pulled a little further. Not long ago, the Foshan Intermediate People's Court publicly heard the case of Struland's patent infringement dispute against the furniture. When the plaintiff, Stirling, showed nearly 10 sets of iron certificates including physical sofas, the new evidence of the defendant's left and right sofas made the case confusing: after the application of the appearance patent in Stirling, the left and right sofas immediately applied. patent. The basis for the patents of the left and right sofas is reported to be only "the appearance of the patent application of the sun-drenched chair on the left, the left and right sun loungers on the right". Why is such a ridiculous voucher the basis for the official patent review decision? Is it a mistake of the patent staff, or is it another key issue that we have to grasp in the patent dispute between Styroland?... The Xianghe Jingwei Furniture City fan case gradually emerged from the surface. This case has actually been going on for a long time. Regrettably, apart from the sporadic reports of some media such as People's Daily Online and People's Representative Network, why haven't there been more media follow-up reports for a long time? An evaluation report that caused the county's fiscal revenue to lose 15% has not been released? Why is the interest of the shareholder Tan Meiliang being stripped under the broad daylight? Who should be responsible for the loss of Tan Meiliang? In the context of the market economy, the basic property rights issue has been called for for decades, why is it always impossible to clarify? ? What kind of benign rules should be constructed in the interests of the administration, the judiciary, the media, and the enterprises?... When asked about this, the author feels that it is necessary to solve the economic difficulties of the furniture industry and even the entire Chinese market, many times, and It’s not about how high our wisdom is, but whether we have enough courage to face the above detailed problems, because whether it’s an industrial upgrade or a major issue such as the regional economy, it’s probably built on In the middle of the above detailed questions. The problem has been raised, and a sufficiently powerful paradox has been formed. Naturally, it is also a time for problem solving, because Milton has long pointed out: "Although various schools of thought can spread on the earth casually, the truth has already gone in person, let it Let's fight with hypocrisy. Who has seen the truth have been defeated in a bold fight?†Of course, the key question is whether we have enough courage! After all, the current furniture industry culture is “harmonious†as long as it has its own The interests are among them. As long as the public problems of the industry "do not care about themselves", everyone is a group of peace. Sadly, our "harmony" is strictly not called "harmony", but "hometown wish". In the touting of hello and my good-hearted style, it confuses right and wrong, reverses black and white, and blurs. Rules, and then "water fish in the water." In this context, it is difficult to find out what truth to be born and solve the substantive problems of the industry!