CN2442057Y

CN2442057Y - Counter flow stop device

Info

Publication number: CN2442057Y
Application number: CN 00239361
Authority: CN
Inventors: 陈键明; 虞之日; 陈炎明; 陈坤明
Original assignee: Yongxing Valve Mfg Co ltd Jiuj
Current assignee: FOSHAN NANHAI YONGXIN VALVE MANUFACTURING Co Ltd
Priority date: 2000-09-05
Filing date: 2000-09-05
Publication date: 2001-08-08
Anticipated expiration: 2010-09-05

Abstract

The utility model relates to a counter flow prevention device which is characterized in that the utility model is composed of a water inlet non-return valve, a water outlet non-return valve and a by-pass water drain valve, wherein, the water drain valve is arranged between the water inlet non-return valve and the water outlet non-return valve. The utility model has the advantages of reasonable and compact structure, convenient maintenance, stable work of a spring and long service life. The utility model severely restricts water or media which have similar physicochemical properties to clear water to flow in one way in pipelines, reliably prevents counter flow, and thus stops counter flow pollution.

Description

Backflow preventer

The utility model relates to a kind of preventer, particularly a kind of backflow preventer.

In all kinds of water supply lines, at present the various safety check that use can not prevent effectively that all press water from flowing to main and backflow pollution takes place from arm is counter, especially in the water supply network of Drinking Water, backflow pollution has taken place people healthy brought serious harm.In flow, become the unsafe hidden danger of feed flow.

It is a kind of rational in infrastructure that the purpose of this utility model is to provide, and can prevent refluence under any water supply situation reliably, thereby stop the backflow preventer of backflow pollution.

The purpose of this utility model can reach by following measure: the utility model by the water inlet safety check, go out Water Check Valve and form with the drain valve of its bypass.Drain valve is installed in into the water safety check and goes out between the Water Check Valve.

The purpose of this utility model can also reach by following measure: drain valve by bolton water inlet safety check waterexit end flange with go out between the Water Check Valve feed-water end flange, communicate with the top of drain valve by flexible pipe at the feed-water end of the safety check of intaking.Leading truck in the water inlet safety check, flap, valve rod, spring, spring seat constitute valve hole part, and are installed in the valve seat by the leading truck insertion, and the spring seat of the other end is positioned at the lower end of valve gap, and the flap lower end is provided with seal ring.Water inlet in the water inlet check valve body also can be provided with filter.The leading truck, flap, valve rod, spring, the spring seat that go out in the Water Check Valve constitute valve hole part, and are installed in the valve seat by the leading truck insertion, and the spring seat of the other end is positioned at the valve gap lower end, and the flap lower end is provided with seal ring.The upper and lower of active chamber is equipped with valve seat respectively in the drain valve valve body, spool is an open-shut device, be provided with " O " RunddichtringO between its underpart and the valve seat, flap is equipped with on top, and by rubber seal, the middle part is provided with the rubber parts of assist location, and the diaphragm of rubber sheet is located at the flap top, and be pressed on the valve body by the drain valve valve gap, open the element spring and be locked on the end cap of valve body by minor axis.Flexible pipe communicates with the epicoele of drain valve diaphragm.

Fig. 1 is structure master of the present utility model (a cuing open) view;

Fig. 2 is a structure plan view of the present utility model;

Fig. 3 is that A-A of the present utility model is to sectional view.

The utility model is described in further detail below in conjunction with accompanying drawing (embodiment):

With reference to Fig. 1～Fig. 3, the utility model by water inlet safety check 1, go out Water Check Valve 25 and form with the drain valve 10 of its bypass, drain valve 10 usefulness bolts 2 are to be fastened between two safety check pressing from both sides formation.Feed-water end at water inlet safety check 1 communicates by the epicoele of rubber hose 28 with the diaphragm of rubber sheet 12 of drain valve 10.

Water inlet safety check 1 and to go out the structure of Water Check Valve 25 basic identical all adopts the valve pocket of the spacious runner of half line current " Y " molded breadth, and it is little to have a loss of head, and the anti-cavitation ability is strong, and noise is low, vibrates characteristics such as little.Water inlet safety check 1 comprises valve body 1-1, leading truck 1-2, valve seat 1-3, seal ring 1-4, flap 1-5, valve rod 1-6, spring 1-7, spring seat 1-8, valve gap 1-9 etc.Form valve hole part by leading truck 1-2, flap 1-5, spring 1-7, valve rod 1-6, spring seat 1-8, and insert in the valve seat 1-3 that is installed on the valve seat 1-1 by leading truck 1-2; The spring seat 1-8 of the other end is positioned at the lower end of valve gap 1-9, and assembling back valve gap 1-9 makes the rubber seal 1-4 that is embedded in flap 1-5 lower end obtain design pressure and valve seat 1-3 sealing by the spring 1-7 that spring seat 1-8 compression has locked.Go out Water Check Valve 25 and comprise valve body 25-1, leading truck 25-2, valve seat 25-3, seal ring 25-4, flap 25-5, valve rod 25-6, spring 25-7, spring seat 25-8, valve gap 25-9 etc., its structure is identical with water inlet safety check 1, no longer narration.Other also can be provided with filter 1-10,1-11 (also can not establish filter) at the intake water inlet of check valve body 1-1.

Drain valve 10 comprises that drain valve valve gap 11, diaphragm of rubber sheet 12, valve debate 14, rubber pad 15, valve seat 16,20, spool 17, rubber parts 18, minor axis 19, end cap 22, spring 23 etc.The upper and lower of valve body 10 active chambers is respectively equipped with valve seat 16,20.Spool 17 is an open-shut device, is sealed by " O " RunddichtringO 24 between its underpart and the valve seat 20; Flap 14 is equipped with on top, and by rubber pad 15 sealings; The middle part is provided with the rubber parts 18 of assist location.Closing driving element is diaphragm of rubber sheet 12, is located at flap 14 tops, and is pressed on the valve body by valve gap 11.Open on the end cap 22 of element spring 23 by minor axis 19 locking valve bodies.

When water was in the moving state of permanent current, the current with P1 (inlet pressure) pressure were after water inlet safety check 1, and owing to loss of head, pressure is reduced to P2, and flows to the cavity of resorption of drain valve 10 bypass flow channel to diaphragm 12; At this moment pressure differential deltap P=P1-P2=0.024Mpa of the total existence in diaphragm 12 upper and lower chambeies.Inlet's hydraulic pressure height overall is in water outlet place hydraulic pressure during proper flow, and water is very smooth in backflow preventer, and the flow size all can not flow backwards.At this moment under the effect of drain valve diaphragm 12 upside Δ P.Overcome spring 23 resistances such as grade, spool 17 is moved downward, drain valve is in closed condition, does not sluice.Obviously Δ P and spring force and resistance to motion are to calculate by accurate, tight waterpower and mechanical force.

When being in dead head condition, water inlet safety check 1 and go out Water Check Valve 25 and all be in closed condition.If the import water pressure invariableness is constant in design pressure, then still greater than following cavity pressure, pressure differential deltap P is constant for drain valve diaphragm 12 upper cavity pressures, and drain valve 10 is in closed condition, and water can not flow backwards and leak.If import hydraulic pressure descends, or because of the working conditions change downstream water presses liter, even go out Water Check Valve 25 leakages, then Δ P just reduces thereupon, when Δ P equals or during near 0.02Mpa, drain valve spool 17 is under spring 23 effects, move upward, drain valve 10 is opened sluicing and is covered air.Sluice owing to prevented before the critical pressure that refluence takes place, so stopped the possibility of this operating mode generation backflow pollution.

When being in the siphon state, no matter in any operating mode, as long as import pressure of supply water P1 drops to or during less than 0.023Mpa, drain valve 10 is necessarily opened, and carries out its air inlet---the dual functions of draining.And the safety check 1 and go out Water Check Valve 25 and all be in closed condition of at this moment intaking.If the rapid drawdown of import water pressure, and produce negative pressure (being that P1 is less than zero), when siphon occurring, no matter whether two safety check leak, drain valve 10 can both be discharged water, and mends a large amount of enough air by the bucket 21 that leaks that communicates with atmosphere, anti-flowing water must not be sucked the import main.Prevented backflow pollution reliably.Have only when import hydraulic pressure P1 during more than or equal to valve pocket pressure P 2 (0.024Mpa) drain valve 10 just close and reset.

The utility model has following advantage compared to existing technology: compact conformation is reasonable, maintenance Convenient, spring stable working, long service life; Can strictly limit ducted water or physics Learning the medium that character is similar to clear water can only one-way flow, prevent from reliably flowing backwards, thus Du Exhausted backflow pollution.

Claims

1, a kind of backflow preventer is characterized in that: by water inlet safety check (1), go out Water Check Valve (25) and form with the drain valve (10) of its bypass, drain valve (10) is installed in into water safety check (1) and goes out between the Water Check Valve (25).

2, preventer according to claim 1, it is characterized in that: drain valve (10) is fastened on into water safety check (1) waterexit end flange by bolt (27) and goes out between Water Check Valve (25) the feed-water end flange, communicates by the top of flexible pipe (28) with drain valve (10) at the feed-water end of water inlet safety check (1).

3, preventer according to claim 1, it is characterized in that: the leading truck (1-2) in the water inlet safety check (1), flap (1-5), valve rod (1-6), spring (1-7), spring seat (1-8) constitute valve hole part, and insert by leading truck (1-2) and to be installed in the valve seat (1-3), the spring seat of the other end (1-8) is positioned at the lower end of valve gap (1-9), and flap (1-5) lower end is provided with seal ring (1-4).

4, preventer according to claim 1 is characterized in that: the water inlet in water inlet check valve body (1-1) also can be provided with filter (1-10), (1-11).

5, preventer according to claim 1, it is characterized in that: the leading truck (25-2), flap (25-5), valve rod (25-6), spring (25-7), the spring seat (25-8) that go out in the Water Check Valve (25) constitute valve hole part, and insert by leading truck (25-2) and to be installed in the valve seat (25-3), the spring seat of the other end (25-8) is positioned at valve gap (25-9) lower end, and flap (25-5) lower end is provided with seal ring (25-4).

6, preventer according to claim 1, it is characterized in that: on the interior active chamber of drain valve (10) valve body, the below is equipped with valve seat (16) respectively, (20), spool (17) is an open-shut device, be provided with " O " RunddichtringO (24) between its underpart and the valve seat (20), flap (14) is equipped with on top, and by rubber pad (15) sealing, the middle part is provided with the rubber parts (18) of assist location, diaphragm of rubber sheet (12) is located at flap (14) top, and be pressed on the valve body by drain valve valve gap (11), open element spring (23) and be locked on the end cap (22) of valve body by minor axis (19).

7, according to claim 2 or 6 described preventers, it is characterized in that: flexible pipe (28) communicates with the epicoele of drain valve diaphragm (12).