倒流防止器
Backflow preventer
概述
倒流防止器是我公司根据我国目前的供水管网，尤其是生活饮用水管网因回流污染严重又无有效防止回流污染装置的情况下，吸收国外先进技术研制而成的一种限制管道中的回流污染的新型水力控制阀门。它采用独特的结构型式，经过严谨科学的设计计算，辅以精心制造，能彻底防止任何情况下的倒流污染，从而确保了人类生活饮用水和生产工艺流程的卫生和安全。适用于生活饮用水管道与接出的用于非生活饮用水管道的交叉处，市政自来水接入用户的靠近户管水表出口处，串联了加压泵或各类增压设备的生活饮用水管道上的吸水道上以及各类生产工艺流程中不允许介质倒流的管道中。如果采用防污止回阀组直接串联调速水泵的供水方式，可取消水池和水箱节约投资成本而且可充分利用自来水厂的供水压力，减少了水泵的扬程，节约了加压供水的电耗，经济效益和社会效益十分可观。
summarize
Backflow preventer is a new hydraulic control valve developed by our company according to the current water supply network in our country, especially the domestic drinking water network because of serious backflow pollution and no effective device to prevent backflow pollution, absorbing foreign advanced technology to limit backflow pollution in the pipeline. It adopts a unique structural type, through rigorous scientific design calculation, supplemented by careful manufacturing, can completely prevent any backflow pollution under any circumstances, so as to ensure the health and safety of human drinking water and production process. It is suitable for the intersection of drinking water pipeline and non-drinking water pipeline, the outlet of municipal tap water access to the user near the household pipe water meter, the suction channel on the drinking water pipeline connected with a pressurized pump or various pressurized equipment, and the pipeline that does not allow the media to flow back in various production processes. If the use of antifouling check valve group direct series speed regulating pump water supply mode, can cancel the pool and water tank to save investment costs and can make full use of water supply pressure, reduce the head of the pump, save the power consumption of pressurized water supply, economic and social benefits are very considerable.
产品结构及工作原理
倒流防止器由进水止回阀，出水止回阀和泄水阀三个部件组成，设有特定的弹簧锁定机构。止回阀采Y型直通式结构，具有流阻小，启闭及时可靠，寿命长及易维护等优点；泄水阀结构采用独特的“进气排水设计”具有动作灵敏，预防背压倒流和虹吸倒流污染等其它任何止回阀所不能取代的优良特性。
在下列流动情况下，防污止回阀组能产格防止水倒流。
正常流动状态时，进口处的供水压力总是高于出口处的水压力，水能很顺利流过防污止回阀组作正向流动。这时水端水压总是高于阀腔内水压，存在一个压差△P,这个压差驱动旁通的泄水阀处于关闭状态，泄水阀不泄水，零流量状态时，出水管上或用水点无出流、进、出水止回阀都处于关闭快状态，当进口端供水压力保持恒定，进水端的水压仍高于阀腔内水压，泄水阀保持关闭状态，当进口端供水压力下降进水端的压力只高于阀腔0.012~0.024MPa左右时，旁通泄水阀就开启泄水，将阀腔内的水排出。
当出水管路因某种原因而水压升高，防污止回阀组出口端的水压高于阀腔内水压，只要出水止回阀不泄露，泄水阀不开启泄水；若出水止回阀泄漏阀腔内的水压随之升高，泄水阀开启泄水，反虹吸状态时，防污止回阀组的进口端压力下降至≤0.0234MPa时，无论阀腔内的压力多大，泄水阀开启泄水，当阀腔内的水被泄空，空气进入阀腔，形成空气隔断，进口端水压即使继续下降形成负压，也不会产生虹吸倒流。
Product structure and working principle
The backflow preventer is composed of three parts: inlet check valve, outlet check valve and discharge valve, and is provided with a specific spring locking mechanism. The check valve adopts Y-type straight through structure, which has the advantages of small flow resistance, timely and reliable opening and closing, long service life and easy maintenance. The drainage valve structure adopts a unique "intake drainage design" with sensitive action to prevent back overflow and siphon backflow pollution and other excellent characteristics that can not be replaced by any other check valve.
In the following flow conditions, the anti-fouling check valve group can produce a grid to prevent water backflow.
In the normal flow state, the water supply pressure at the inlet is always higher than the water pressure at the outlet, and the water can smoothly flow through the antifouling check valve group for positive flow. At this time, the water pressure at the water end is always higher than the water pressure in the valve chamber, there is a pressure difference △P, this pressure difference drives the bypass drainage valve in the closed state, the drainage valve does not discharge water, zero flow state, the outlet pipe or water point no flow, inlet, outlet check valve are closed fast, when the inlet water supply pressure remains constant, the water pressure at the inlet end is still higher than the water pressure in the valve chamber. The drain valve is kept closed. When the water supply pressure at the inlet end drops and the pressure at the inlet end is only about 0.012~0.024MPa higher than the valve chamber, the bypass drain valve will open the drain and discharge the water in the valve chamber.
When the water pressure of the outlet pipe rises for some reason, the water pressure at the outlet end of the anti-pollution check valve group is higher than the water pressure in the valve chamber, as long as the outlet check valve does not leak, the discharge valve does not open the discharge valve. If the water pressure in the leakage valve chamber of the outlet check valve increases, the discharge valve opens the discharge valve, and when the anti-pollution check valve group's inlet pressure drops to ≤0.0234MPa, the discharge valve opens the discharge valve regardless of the pressure in the valve chamber. When the water in the valve chamber is drained, the air enters the valve chamber and forms an air partition. Even if the water pressure at the inlet end continues to decline, negative pressure will be formed. There's no siphon backflow.
主要连接外形尺寸
Main connection dimensions
