JPS6231793A - Pipe joint for preventing water hammer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] This invention can alleviate water hammer that occurs when starting and stopping a pump by installing it in a liquid pipe, and can further absorb the residual pulsation. This relates to pipe fittings.

Conventionally, large amounts of energy generated by pressure waves generated within pipes have been absorbed by installing check valves and absorbing water hammer and pulsating waves by using shock absorbers such as elastic cheep inside a casing filled with pressurized gas. The disadvantage was that the construction costs were high.

In addition, both the installation of only a check valve and the installation of only a pulsation absorber have the disadvantage that water hammer and pulsation cannot be alleviated, and at the same time, since the elastic tube uses an elastic polymer,
The disadvantage is that the temperature and pressure of the fluid imposes restrictions on its use.

This invention eliminates the above-mentioned drawbacks of the conventional technology, buffers water hammer energy, absorbs residual pulsation, reduces construction costs, and greatly improves the scope of use. The purpose is to provide pipe fittings.

The present invention will be explained below with reference to the illustrated embodiments.

As shown in FIG. 1, the water hammer prevention pipe joint of the present invention is
A casing 1, a pipe 2, and a check valve 9 with two blades are placed in the center of a fluid passage, and a buffer spring 10 and a
It has a mechanism in which check valves 1 are installed on the upstream and downstream sides, and check valve 9 is installed in the middle. Inside the casing 1 there is a lumen 3 through which fluid flows as a bypass. The pipe 2 is provided with an annular ring 12 fitted in the through holes 4 and 5 and a step cavity 6 in the circumferential inner wall, and the pipe 2 is installed using the inner peripheral wall of the through hole 4 and the outer peripheral wall of the annular ring 12 as guides. The pipe 2 is provided with an arbitrary number of perforations 7 that pass through the lumen 3 of the casing 1, and the check valve 9 bypasses the lumen 3 in the process of moving upstream and downstream due to fluctuations in fluid pressure. As a passage, it absorbs and alleviates water hammer pressure or pulsating waves when the pump starts and stops.

A check valve 9 is placed between the casing 1 and the pipe 2 to form a flow path 4'A and a downstream flow path 5'B, and an upstream buffer spring 10 and a downstream buffer spring 1, respectively.
1 is in contact.

Figure 2 shows the check valve 9 and pipe 2 along the line ■-■ in Figure 1.
and a cross-sectional view of the casing 1.

The check valve 9 includes two semicircular valve bodies 13a and 13b,
An annular mouth rim 17 formed inside the valve housing by a pin 15 attached across the inner diameter of the valve housing via hinges 14a and 14b and a coil spring 16 with a biasing force attached to the pin 15, and its radial edge are provided with a tendency to close at all times so as to abut against support members 18 provided across the radial direction. The pin 21 is a stop pin provided to restrict rotation when the two valve bodies 13a and 13b rotate against the biasing force of the spring 16.

FIG. 3 shows the state in which the pump is activated, fluid pressure is applied from the upstream side 4'A, and the check valve 9 has finished moving inside the pipe 2 against the downstream buffer spring 11. When the stop valve 9 moves downstream, the sudden water hammer pressure and pulsating wave energy at the start of pump operation are absorbed. Upon receiving the pressure, the two valve bodies 13a and 13b of the check valve 9 resist the biased spring 16, and the check valve 9 becomes open, and the fluid begins to flow downstream of the passage 5'B. , almost simultaneously, as the check valve 9 begins to move downstream, the check valve 9 moves from the perforation 7 of the pipe 2 to the position shown in FIG. The fluid in the bypass passage continues to flow while it communicates with the side annular sheet passage 5'B, which is effective in absorbing shock pressure and pulsating waves during pump operation.

Next, when the pump etc. is stopped, the fluid normally flowing in the pipes starts to flow backwards, causing a water head phenomenon. The interior begins to move upstream, and the two valve bodies 13a and 13 of the check valve 9
b is pushed by the spring 16 with biasing force, and the check valve 9 is closed, and at the same time, as the check valve 9 moves upstream, the inner cavity of the casing 1 is opened from the perforation 7 on the downstream side of the pipe 2. 3, and the upstream hole 7 of the pipe 2 communicates with the bypass passage until the check valve 9 comes into contact with the annular seat 19 shown in FIG. 1 against the biasing force of the upstream spring 11. During this time, the fluid with backflow pressure continues to flow, and the backflow impact pressure and pulsating wave pressure are efficiently absorbed by the synergistic effect with the buffering action of the upstream buffer spring 10.

In this case, the spring strength of the buffer springs 10 and 11 is set such that when the pump is stopped, the check valve 9 comes into contact with the annular seat shown in FIG. 1 due to the piping water column pressure, and a complete check seal is achieved.

Since this invention is constructed as described above, it simultaneously buffers water hammer and eliminates residual pulsation by all functions of the fluid flow in the check valve and the bypass passage, and the cushioning properties of the spring that supports the check valve. It can be used in a wide range of applications, including high temperature and high pressure fields, depending on the selection of the metal used. Moreover, there is no need to separately install a mechanism for damping water hammer and a mechanism for absorbing residual pulsation in the pipeline, which has the effect of reducing installation costs.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the casing 1 and the check valve taken along line 1n--n in FIG. 1. Figure 6 (Fig. 61) 61...Casing 2...Pipe 3...
...Vacancy 4,5...Through hole 7...Perforation
9...Check valves 10, 11...
Buffer springs 13a, 13b - Valve body Patent applicant Tozen Sangyo Co., Ltd. Figure 1

Claims (1)

[Claims] (1) A casing with a fluid passage lumen inside and fluid passage holes on both sides, a pipe with an arbitrary number of perforations on the wall inside the casing, and a pipe with an arbitrary number of perforations on the wall, and The check valve has two valve bodies that are always biased toward closing by a biasing member spring, and each biasing member buffer spring is installed internally on the upstream and downstream sides to hold the check valve in the middle. It is made to be able to freely move upstream and downstream in the pipe due to fluctuations in fluid pressure, and the fluid passage lumen inside the casing is used as a bypass hole to absorb the water hammer pressure of the fluid.
In addition, this water hammer prevention pipe joint has a mechanism in which the biasing member, the buffer spring, which holds the check valve in the middle, simultaneously absorbs residual pulsation when the fluid flow starts and stops.