Water hammering prevention device

Details Water hammering prevention device Water hammering prevention device

2000-12-21

2002-07-09

Michalsky, Gerald A. (Department: 3753)

Fluid handling

Back flow prevention by vacuum breaking

Air vent in liquid flow line

C137S543000

Reexamination Certificate

active

06415810

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a water hammering prevention device.
2. Description of the Prior Art
It has been a common practice to use an accumulator installed in the middle of the piping system of the water supply device to achieve such an object.
Such a device has a sealed container whose inside is divided into the water supply pressure side and the pressure suction side by means of a rubber bladder, diaphragm, piston,. etc., so that the pressure surge due to the water hammering action generated at the water supply pressure side can be absorbed.
However, there was a limit to the absorption of the pressure surge due to the water hammering action because the pressure absorption side of the abovementioned device is a closed space.
SUMMARY OF THE INVENTION
With the abovementioned problem in mind, the present invention intends to provide a water hammering prevention device including: an outer box having concentric flow paths for an inlet and an outlet and a drain port in the midstream section of the flow path; an inner tube member having a diaphragm on its periphery dividing the inside of the outer box into an upstream section and an area consisting of a midstream section and a downstream section of the flow path, wherein the inner tube member slidingly fits into the upper section; a relief valve is provided on the end face of the downstream side opening of the inner tube member and the relief valve is capable of moving toward or away from a valve seat located on the periphery of a valve port provided between the midstream section and the downstream section and energized by a relief valve spring toward the valve opening direction; and a check valve provided inside the inner tube member to prevent fluid from flowing backward from the downstream side, thus solving the abovementioned problem by discharging the pressurized water caused by the water hammering action to the outside via the drain port.
The invention, constituted as such, checks the upstream side with the check valve
5
and opens the relief valve
4
when the back pressure rises above the upstream pressure due to water hammering, so that the back pressure from downstream can be discharged to the outside through the drain port
9
, thus eliminating noise and vibration due to water hammering completely and drastically reducing piping system problems, which used to be caused at least partially by noise and vibration due to water hammering.
In accordance with one aspect of the invention, the water hammering prevention device is installed parallel to the check valve
38
installed in the piping
39
of the water supply device
34
, or directly in the piping
39
, and the drain port
9
is connected via piping to the water receiving tank
35
, so that it not only prevents water hammering completely but also it adds an economic effect of eliminating wasteful use of water as the water drained from the drain port
9
is returned to the water receiving tank
35
.
In accordance with another aspect of the invention, a water hammering prevention device is connected to each of the terminal devices
51
,
51
a
of the water supply device
45
and their drain ports
9
are connected to the outside, so that it is capable of preventing water hammering caused by frequent high back pressure rises due to repeated turning on and off of the water supply, particularly when the terminal devices
51
,
51
a
are high pressure water injection guns, by discharging the high pressure fluid to the outside through the drain port
9
.
By connecting the drain ports
9
via piping to the water receiving tank
47
, water waste can be prevented as well.
In accordance with a further aspect of the invention, the effective diameter D
1
of the diaphragm
14
and the valve seat diameter D
2
of the valve seat
11
are chosen to be about equal so that the valve closing pressure of the relief valve
4
that the diaphragm
14
receives and the valve opening pressure that the relief valve
4
itself receives can be balanced and the spring loads F and f of the relief valve spring
17
and the check valve spring
28
respectively are chosen to maintain the pressure P
2
of the midstream section
8
b
always lower than the upstream side pressure P
1
by a margin of &Dgr;P of a constant value. It is therefore possible to provide, by setting the pressure difference &Dgr;P between the pressure P
2
of the midstream section
8
b
and the upstream side pressure P
1
to match the individual characteristic of a water supply device, a specific valve opening characteristic for the relief valve
4
to suit the characteristics of a particular water supply device, thus being able to provide a water hammering prevention device
1
that fits with any water supply device.
In accordance with another aspect of the invention, the inner tube member
3
is formed to have a circular cross section, while the sliding surface
12
of the inside of the outer box
2
that fits with the inner tube member
3
has grooves
13
,
13
a
equally spaced along its circumference, so that it is possible to reduce the sliding contact area between the inner tube member
3
and the sliding surface
12
and to make the inner tube member
3
thinner and lighter without sacrificing strength, thus contributing to reducing the sliding resistance of the inner tube member
3
as much as the strength of the inner tube member allows. Consequently, it is possible to improve the water supply performance because of the reduction of the pressure loss of the pressurized fluid during the water supply period and to use a smaller water supply pump for the water supply device.
In accordance with yet another aspect of the invention, it is possible to reduce the friction resistance of the inner tube member
3
against the outer box
2
because of a coating on the outer circumference of the inner tube member
3
of Teflon and to reduce the pressure loss in the same way as in the case above.
In accordance with still another aspect of the invention, the check valve
5
has a flat surface
30
formed on its face
29
confronting the check valve port
18
, the surface having a diameter smaller than the check valve port
18
, and a conical apex
31
formed in the middle of the flat surface
30
. Furthermore, multiple tilting grooves
33
,
33
a
are provided having a groove width decreasing gradually toward the center of the back of the check valve
5
from the outer periphery, which is further outside of a seating area
32
corresponding to the check valve seat
19
. These tilting grooves
33
,
33
a
are equally spaced in the circumferential direction on the check valve
5
. As a result, water flows smoothly from upstream to downstream along the shape of the check valve
5
without causing any swirls on the back of the check valve
5
, thus minimizing the pressure loss due to the check valve inserted in the flow path
8
. It provides similar effects as mentioned above and its practical benefit is significant.


REFERENCES:
patent: 3744507 (1973-07-01), Oberthur
patent: 3818929 (1974-06-01), Braukmann
patent: 3905382 (1975-09-01), Waterston
patent: 3908689 (1975-09-01), Wingate
patent: 4013089 (1977-03-01), Braukmann
patent: 4518006 (1985-05-01), Hoffmann et al.
patent: 5960818 (1999-10-01), Hecking
patent: 24 14 893 (1975-10-01), None

Affiliated with

Also associated with

Rating

Water hammering prevention device does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Water hammering prevention device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Water hammering prevention device will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2824994