CN204114259U - There is the reduction valve of valve closing function - Google Patents

Abstract

The utility model discloses a kind of reduction valve with valve closing function, it is characterized in that: have center hole in the central authorities of valve body across bulkhead, be provided with valve seat cover in center hole, the upper and lower end of valve seat cover forms upper and lower two valve ports with the pressing plate and gasket base being arranged at valve rod corresponding site; The upper-end surface of valve seat cover is provided with annular groove, and be provided with O-ring seals in groove, as the valve seat of upper valve port, pressing plate is as the flap of upper valve port; The lower end surface of valve seat cover is provided with annular sword limit, as the valve seat of lower valve port, has sealing gasket above gasket base, and both use fastening nuts on valve rod, as the flap of lower valve port.Described bottom flange and gasket base are provided with spring one between going to the bottom.The utility model is when diaphragm damages, and upper valve port can be closed automatically; When the downstream long period does not need water, lower valve port is closed and is produced enough sealing forces.The consequence that these two kinds of situations can avoid upstream device to damage.

Description

There is the reduction valve of valve closing function

Technical field

The utility model relates to a kind of reduction valve, particularly relates to a kind of reduction valve with valve closing function.

Background technique

Reduction valve has been widely used in water supply system and heating ventilation air-conditioning system, efficiently solves pressure and flow that pressure regulates problem and control water spot.The reduction valve supplied in the market, in order to improve degree of regulation and simplified structure, adopts diaphragm structure mostly, when acting on the power disequilibrium on valve rod, drives it to move up and down by diaphragm, is opened by valve port large or turns down, to ensure that delivery pressure is constant.Compared with piston type, its main deficiency is that diaphragm is more fragile, because diaphragm is mounted in valve inner, when damage user unknown, once damage, reduction valve does not recur decompression, and valve port is all opened, high-pressure medium can flow to valve or the pipeline in downstream, causes the device damage in downstream.

Diaphragm type pressure-reducing valve also has a problem, when the downstream long period does not need water, valve port can be closed automatically, but because the size Selection of the parts such as diaphragm is improper, cause sealing force inadequate, the high pressure water of upstream will be leaked to downstream by the gap between valve seat and sealing gasket, causes the pressure in downstream line to raise, can cause the damage of upstream device equally.

Summary of the invention

The purpose of this utility model designs for solving the deficiencies in the prior art, and be a kind of when diaphragm damage, valve port can be closed automatically; Or the downstream long period is not when needing water, flap and valve seat have the reduction valve of enough sealing forces.

Above-mentioned technical problem of the present utility model is mainly solved by following technical proposals: a kind of reduction valve with valve closing function, there is valve body, valve rod, described valve body has upper and lower through hole, and the snout cavity of valve body and outlet plenum horizontal arrangement, have bonnet above valve body, spring chamber is had in bonnet, have bottom flange below valve body, there are guide holder in bottom flange central authorities, are provided with spring two and diaphragm between valve body and bonnet, described diaphragm and valve rod upper end portion are connected, and it is characterized in that:

Have center hole in the central authorities of valve body across bulkhead, be provided with valve seat cover in described center hole, the upper and lower end of described valve seat cover forms upper and lower two valve ports with the pressing plate and gasket base being arranged at valve rod corresponding site;

The upper-end surface of described valve seat cover is provided with annular groove, and be provided with O-ring seals in described groove, as the valve seat of upper valve port, described pressing plate is as the flap of upper valve port;

The lower end surface of described valve seat cover is provided with annular sword limit, as the valve seat of lower valve port, has sealing gasket above described gasket base, and both use fastening nuts on valve rod, as the flap of lower valve port.

Described bottom flange and gasket base are provided with spring one between going to the bottom.

The technical solution of the utility model can also be perfect further:

As preferably, water supply process when diaphragm damages, the closing forces of upper valve port:

F ₁＝P ₁×π/4(d ₂ ²-d ₁ ²)+f ₁-f ₂ (1)

In formula:

P ₁-import hydraulic pressure;

D ₁the respective diameters of-valve rod;

D ₂the diameter of bore of-valve seat cover;

F ₁the down pressure of-spring two;

F ₂-spring one to lifting force;

Reliable in order to ensure at the most unfavorable processing condition lower seal, must ensure:

P ₁min×π/4(d ₂ ²-d ₁ ²)-f ₂≥F ₁min (2)

In formula

P ₁the minimum import hydraulic pressure of min-

F ₁mim-ensures the reliable minimum closing forces of sealing.

As preferably, when downstream does not need water, after lower valve port (V2) is closed, in order to ensure that sealing is reliable, following condition must be met:

P ₂×S-P ₁×π/4(d ₂ ²-d ₁ ²)-f ₁+f ₂≥F ₂min (3)

In formula

P ₂-outlet hydraulic pressure, lower than upstream device or pipeline permitted permit pressure;

The lifting surface area of S-diaphragm

F ₂min-guarantees the minimum sealing force that lower valve port is reliably closed.

The utility model beneficial effect is:

When diaphragm damages, due to the stressed disequilibrium of valve rod, valve port can be closed automatically, and upstream stops to downstream water supply, avoids upstream high current direction downstream;

When the downstream long period does not need water, valve port is closed and is produced enough sealing forces, stops upstream high water to leak to downstream.

Thus the consequence avoiding upstream device to damage.

Accompanying drawing explanation

Accompanying drawing 1 is a kind of structural representation of the present utility model.

Description of reference numerals:

1, diaphragm, 2, valve body, 3, valve rod, 4, O-ring seals, 5, across bulkhead, 6, valve seat cover, 7, sealing gasket, 8, gasket base, 9, spring one, 10, spring two;

A, water-inlet cavity, B, water chamber, V ₁, upper valve port, V ₂, lower valve port, m, pressing plate.

Embodiment

Below by embodiment, and by reference to the accompanying drawings, the technical solution of the utility model is described in further detail.

Embodiment:

The reduction valve with valve closing function as shown in the figure, have valve body 2, valve rod 3, described valve body 2 has upper and lower through hole, the snout cavity A of valve body and outlet plenum B horizontal arrangement, bonnet is had above valve body, have spring chamber H in bonnet, have bottom flange below valve body, there are guide holder in bottom flange central authorities, diaphragm 1 is provided with between valve body 2 and bonnet, described diaphragm 1 is connected with valve rod 3 upper end portion, and the utility model and the common reduction valve main distinction structurally have two valve ports, upper valve port V ₁and lower valve port V ₂.In the central hole of valve body 2 across bulkhead 5, be provided with valve seat cover 6, in the groove of the upper-end surface of valve seat cover 6, be provided with O-ring seals 4, as upper valve port V ₁valve seat; The pressing plate m be connected with it is provided with, as upper valve port V in the stage casing of valve rod 3 ₁flap; The lower end of valve rod 3 is provided with the sealing seat 8 and sealing gasket 7 of using fastening nuts, as lower valve port V ₂flap; Valve seat overlaps the annular sword limit of 6 lower ends as lower valve port V ₂valve seat.Spring 1, in order to when P≤0 (such as upstream cut off the water maintenance or the situation such as pipeline breaking), does not cause valve port V ₁close, in order to avoid medium cannot enter outlet plenum B from snout cavity A when again starting.The center line of above-mentioned part is consistent with the vertical center line of the upper and lower through hole of valve body 2 after mounting.

1, in water supply process, valve rod 3 is stressed is balance all the time on dynamically, therefore can ensure delivery pressure P ₂substantially constant.When diaphragm 1 damages suddenly, the press water passing hole C of outlet plenum enters into spring chamber H, the upper and lower pressure of diaphragm 1 is equal, the stressed disequilibrium of valve rod 3, under the pressure effect of spring 2 10, the part such as diaphragm 1, valve rod 3 moves downward, till the lower plane of pressing plate m contacts with O-ring seals 4, upper valve port V1 closes, and the sealing reliability after upper valve port V1 closes is calculated as follows:

Because the top of medium from flap 7 flows into, below is flowed out, and during valve closing, reduction valve loses decompression, therefore P ₂go to zero, therefore closing forces

F ₁＝P ₁×π/4(d ₂ ²-d ₁ ²)+f ₁-f ₂ (1)

In formula

P ₁-import hydraulic pressure;

D ₁the respective diameters of-valve rod 3;

D ₂the diameter of bore of-valve seat cover 6;

F ₁the down pressure of-spring 2 10;

F ₂-spring 1 to lifting force;

As import hydraulic pressure P ₁the pressure f of minimum and spring 2 10 ₁minimum (under high Pressure reducing ratio operating mode, because spring 2 10 pressure is very loose, therefore f ₁very little, can ignore during calculating) time, closing forces F ₁minimum, reliable in order to ensure at the most unfavorable processing condition lower seal, must ensure:

P1min×π/4(d ₂ ²-d ₁ ²)-f ₂≥F ₁min (2)

In formula

P ₁the minimum import hydraulic pressure of min-;

F ₁min-ensures the reliable minimum closing forces of sealing.

Specify in the design and devdlop code of reduction valve, P ₁min is at least than outlet pressure P ₂high 0.15MPa, outlet pressure P ₂determined by user, for the purpose of sealing reliably, during calculating, get P ₂min=0.1MPa; F ₁min is for ensureing that the endoporus area of valve seat cover 6 is multiplied by the reliable hydraulic pressure of sealing (generally getting 0.05MPa); f ₂specific output hydraulic pressure P ₂the pressure of spring 2 10 bigger (now spring 2 10 is pressed tighter) time maximum, this value can calculate, and also can survey and obtain.Therefore can according to P ₁min, F ₁min and f ₂value calculate d by (2) formula ₁and d ₂relation, then determine d according to the bore of valve and concrete structure ₁and d ₂, due to d ₂comparatively large with flow coefficient relation, size is unsuitable too small.

Now be calculated as follows for DN65 reduction valve:

Get minimum outlet hydraulic pressure P ₂min=0.1MPa=1kg/cm ², so minimum import hydraulic pressure P ₁min=P ₂min+0.15=0.25MPa=2.5kg/cm ²;

Record f ₂=60N=6kg; F ₁min=0.5 × π/4 × d ₂ ²

Each value is substituted into (2) formula obtain: 2.5 × π/4 (d ₂ ²-d ₁ ²)-6>=0.5 × π/4 × d ₂ ²

After arrangement $d_1\≤\sqrt{\frac{{{1.57d}_2}^2-6}{1.96}}$

Get d ₂=3.5cm, then d ₁≤ 2.6cm.

2, when downstream does not need water, outlet hydraulic pressure P ₂raise gradually, the pressure acting on diaphragm 1 cavity of resorption also raises gradually, works as P ₂when rising to certain value, overcome the pressure of spring 10 by lower valve port V ₂close.If the downstream long period does not need water, and when valve closed force is inadequate, so high pressure water P of snout cavity A ₁can by lower valve port V ₂the gap of sealing surface is leaked to outlet plenum B, causes downstream hydraulic pressure P ₂raise, damage can be caused to upstream device equally.

Lower valve port V ₂sealing reliability after closedown is calculated as follows:

In order to Leakage prevention, following condition must be met:

P ₂×S-P ₁×π/4(d ₂ ²-d ₁ ²)-f ₁+f ₂≥F ₂min (3)

In formula

P ₂-outlet hydraulic pressure, lower than upstream device or pipeline permitted permit pressure;

The lifting surface area of S-diaphragm 1;

F ₂min-guarantees lower valve port V ₂the minimum sealing force of reliable closedown;

From (3) formula, prevent lower valve port V ₂first measure of leaking is the area increasing diaphragm 1, but must be appropriate, otherwise valve volume can be excessive; Second measure reduces minimum sealing force F ₂min, for this reason, under the condition not reducing flow coefficient, can reduce the diameter of bore d of valve seat cover 6 ₂, namely reduce d ₂the area of contact of annular sword limit, lower end and sealing gasket 7, but the contact stress of the two can not be made too large, otherwise the life-span of sealing gasket 7 can be reduced.

Calculating should be carried out under the operating mode of high Pressure reducing ratio, because of now P ₂lower, and under the operating mode of Pressure reducing ratio little (such as < 3), due to P ₂relatively high, the condition of (3) formula easily meets.Now connect example to be calculated as follows:

If import hydraulic pressure P ₁=1MPa=10kg/cm ²; Outlet hydraulic pressure P ₂=0.1MPa=1kg/cm ².

Each value is substituted into (3) formula obtain:

S>=42cm ², diaphragm is generally circle, diaphragm diameter D>=7.3cm.

Claims (2)

1. one kind has the reduction valve of valve closing function, there is valve body (2), valve rod (3), described valve body (2) has upper and lower through hole, the snout cavity (A) of valve body (2) and outlet plenum (B) horizontal arrangement, bonnet is had above valve body, spring chamber (H) is had in bonnet, bottom flange is had below valve body, there are guide holder in bottom flange central authorities, diaphragm (1) is provided with between valve body and bonnet, described diaphragm (1) and valve rod (3) upper end portion are connected, and it is characterized in that:

Center hole is had in the central authorities of valve body (2) across bulkhead (5), be provided with valve seat cover (6) in described center hole, the upper and lower end of described valve seat cover (6) forms upper and lower two valve port (V with the pressing plate (m) and sealing gasket (7) being arranged at valve rod (3) corresponding site ₁, V ₂).

2. the reduction valve with valve closing function according to claim 1, is characterized in that:

The upper-end surface of described valve seat cover (6) is provided with annular groove, is provided with O-ring seals (4) in described groove, as upper valve port (V ₁) valve seat, described pressing plate (m) is as upper valve port (V ₁) flap;

The lower end surface of described valve seat cover (6) is provided with annular sword limit, as lower valve port (V ₂) valve seat, described sealing gasket (7) below has gasket base (8), both with fastening nuts on valve rod (3), as lower valve port (V ₂) flap:

Described bottom flange and gasket base (8) are provided with spring one (9) between going to the bottom.