AU650475B2

AU650475B2 - Stop valve

Info

Publication number: AU650475B2
Application number: AU83754/91A
Authority: AU
Inventors: Takashi Tomimoto; Masahiko Yamamoto
Original assignee: Morita Fire Pump Manufacturing Co Ltd
Current assignee: Morita Holdings Corp
Priority date: 1990-10-02
Filing date: 1991-09-09
Publication date: 1994-06-23
Anticipated expiration: 2011-09-09
Also published as: MY107798A; KR0123963Y1; KR920008071U; JPH0462481U; AU8375491A; TW205088B; JP2535848Y2

Description

Our Ref: 405109 P/00/011 Regulation 3:2

AUSTRALIA

650475 Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT *s t*

S

Applicant(s): Morita Fire Pump Mfg. Co., Lt.

5-20, Shoji-higashi Ikuno-ku Osaka-shi OSAKA-FU

JAPAN

ARTHUR S. CAVE CO.

Patent Trade Mark Attorneys Level 10, 10 Barrack Street SYDNEY NSW 2000 Address for Service: Invention Title: Stop valve The following statement is a full description of this invention, including the best method of performing it known to 5020

SPECIFICATION

STOP VALVE BACKGROUND OF THE INVENTION (Field of the Invention) The present invention relates to a stop valve utilized to prevent water from flowing into a vacuum pump used as a priming device for starting a fire extinguishing pump in a fire extinguishing pump system.

(Prior Art) At present, a turbine pump is in general use as a fire extinguishing pump for some reasons. A turbine pump has merits but its demerit is that it requires a priming operation for filling the casing and suction pipe with 0 water when it is to be started; thus, most of the turbine pumps are equipped with vacuum pumps serving as priming gO o devices. There are various types of vacuum pumps, and for fire extinguishing purposes, a small-sized highly efficient one is required. Generally, an eccentric vane type rotary pump is utilized. And vacuum pumps which are used for this purpose are of the oil circulation type and the nonlubricated type to avoid road contamination with lubricating oil.

In a fire extinguishing pump system, when a vacuum pump is used for priming, water flows into the vacuum pump from the fire extinguishing pump tpon completion of the priming 2 operation. In the case of an oil circulation type vacuum pump or nonlubricated type vacuum pump, such flow of water into the vacuum pump has various adverse influences. That is, there is a problem that in the vacuum pump, the oil mixes with water to form an emulsion., and in the case of an nonlubricated type vacuum pump, since the vane wheel is made of a self-lubricating material, carbon, and is therefore brittle, water flowing into the vacuum pump :so entails the danger of the vane wheel being damaged by the impulse of water. Thus, in order to prevent water from flowing into the vacuum pump upon completion of operation Go for priming the fire extinguishing pump, it is usual Spractice to install a stop valve in an air suction pipe which connects the suction pipe of the fire extinguishing pump to the vacuum pump.

A stop valve of this type usually employed is shown in Fig. 2, comprising a diaphragm 3 held between a valve o barrel 1 and an upper lid 2, said diaphragm 3 being connected through a movable rod 6 to an opening and closing valve 5 which opens and closes a valve hole 4 formed in said valve barrel 1. When the vacuum pump is operated, the air in the valve barrel 1 is discharged by the vacuum pump to produce a vacuum therein, causing the diaphragm 3 to be sucked downward and hence the opening and closing valve is also lowered through the agency of the movable rod 6, thereby opening the valve hole 4. As a result, the air in ?he fire extinr uishin pnump is also discharged by the S 0282q/gs 3 vacuum pump to produce a vacuum therein, drawing water from a water source. With the priming operation for the fire extinguishing pump thus completed, water tends to flow from the fire extinguishing pump to the vacuum pump, but since the water pressure lifts the opening and closing valve 5 to close the valve hole 4, thereby preventing water from flowing into the vacuum pump.

With the above-described conventional stop valve used, however, when the vacuum pump is.stopped, air flows back into the fire extinguishing pump, causing a danger of falling of water, and in a certain pumping state, there is a possibility of water flowing into the vacuum pump.

In the conventional stop valve, there is a need to add a check valve to prevent reverse flow of air into the fire extinguishing pump and a float valve-equipped tank for collecting water leaking from the stop valve. For this reason, the device for preventing water from flowing into the vacuum pump becomes large-sized, the piping is complicated and the pumping time is long while depending upon a certain stop timing for the pump, the float valve-equipped tank becomes fail all too soon.

SUMMARY OF THE INVENTION *0* Accordingly, an object of the present invention is to provide a stop valve which has solved the problems described above.

According to one aspect of the present invention there is provided a stop valve comprising: a valve barrel having an inlet port in the lower region and an outlet port in the upper region thereof and formed with a communication port to establish the communication between a primary chamber of said inlet port and a secondary chamber of said outlet port, an opening and closing valve disposed in said primary chamber and adapted to be lifted and lowered to close said communication port, V._C f'- R" .ft: 0282q/gs 4 a ball valve installed in said secondary chamber to open and close said communication port, a float connected to said opening and closing valve in said secondary chamber, said opening and closing valve being shaped to open with the ball valve mounted on the upper end of the communication port when the opening and closing valve closes said communication port.

Preferred embodiments of the invention will hereafter be described with reference to the accompanying drawings in which: Fig. 1 is a longitudinal sectional view showing an embodiment of a stop valve according to the present invention; and o 00 0 *s 5 Fig. 2 is a longitudinal sectional view showing a conventional stop valve.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the invention will now be described with reference to the drawing.

In Fig. 1, the numeral 11 denotes a valve barrel which, in this embodiment, is composed of a lower valve barrel 12 associated with a primary chamber and an upper valve barrel 0 S* 13 associated with a secondary chamber. The lower valve 0* barrel 12 is provided with an inlet port 14 in the lower region thereof and is integrally provided with a support member 15 for liftably supporting an opening and closing valve 23 to be later described, said support member being forped with a suitable number of openings 16. The upper valve barrel 13 is laterally provided with an outlet

*U

port 17 and in the lower region it is provided with a passage purt 18 for establishing the communication between the outlet port 17 and the inlet port 14 of the lower valve barrel 12. The numeral 19 denotes a valve lid mounted on top of the upper valve barrel 13. A ball valve 21 is installed in a guide sleeve 20 suspended into the upper valve barrel 13, said ball valve 21 being mounted on an elastic ring 22 mounted on the upper end periphery of the communication port 18 of the upper valve barrel 13. The numeral 23 denotes an opening and closing valve liftably supported on the support member 15 of the lower valve 6 barrel 12 through the agency of a valve stem 24, it being arranged that it is lifted and lowered by a float installed on the lower end of the valve stem 24 to open and close the lower end periphery of the communication port 18 of the upper valve barrel 13. The opening and closing valve 23 has its upper surface 23a shaped conical so that when said opening and closing valve 23 closes the communication port 18 of the upper valve barrel 13, it interferes with the ball valve 21 mounted on the elastic ring 22 mounted on the upper end periphery of said 0* communication port 18 so that it does not close the communication port 18 at the same time as does the ball valve 21.

With the stop valve of the present utility mode arranged in the manner described above, its operation will now be described.

*0 First, when the vacuum pump is operated, the ball valve 21 is sucked upward in the guide sleeve 20 of the valve lid 19 to open the communication port 18 of the upper valve barrel 13, so that the air in the fire extinguishing pump and in the suction pipe is drawn into the vacuum pump through the inlet port 14, openings 16, communication port 18 and outlet port 17 to evacuate the fire extinguishing pump and suction pipe. Thereby, with the fire extinguishing pump thus evacuated, water is drawn into the fire extinguishing pump from the water source to perform the operation for priming the fire extinguishing pump.

7 With the operation for priming the fire extinguishing pump thus completed, water flows into the lower valve barrel 12 from the fire extinguishing pump, so that the float 25 is pushed up by the water buoyancy or water pressure acting thereon, also pushing up the opening and closing valve 23 through the agency of the valve stem 24 to close the communication port 18, thereby preventing water from flowing into the vacuum pump.

0o4 Thereafter, as soon as the vacuum pump is stopped, air o is drawn into the upper valve barel 13 through the output port 17, pressing the ball valve 21 against the elastic ring 22 mounted on the upper peripheral edge of the 0o 4 "o communication port 18; thus, this time, in place of the opening and closing valve, the ball valve 21 closes the communication port 18. As a result, even if the vacuum pump is stopped, the falling of water in the fire extinguishing pump can be prevented since reverse flow of air into the fire extinguishing pump is prevented.

According to the stop valve of the present invention, it has a check valve function and is adapted to push up the float 25 by the water buoyancy or water pressure until the opening and closing valve 2 closes the communication port 18; therefore, reverse flow of air into the fire extinguishing pump is prevented and so is flow of water into the vacuum pump. As a result, there is no need to add a check valve and a float valve-equipped tank as in the prior art, so that the size of the device for preventing 8 water to flow into the vacuum pump is decreased and there is no need for complicated piping. However, in the case of using a nonlubricated type vacuum pump, a filter-equipped tank is added to prevent the vacuum pump from drawing dust and dirt, but such filter-equipped tank is very small as compared with the conventional float valve-equipped tank, not forming so much hindrance to miniaturization.

Further, according to the stop valve of the present invention, since the communication port 18 is not closed simultaneously by the ball valve 21 and the opening and closing valve 23, the communication port 18 is not evacuated, ensuring that the opening and closing valve operates normally. That is, if the communication port 18 is closed simultaneously by the ball valve 21 and the opening and closing valve 23, the communication port 23 is evacuated so that even if no water remains in the lower valve barrel 12, the communication port 18 remains closed by the opening and closing valve 23, leading to the drawback that air can no longer be drawn even if the vacuum S* pump is operated.

In addition, in the present embodiment, the valve barrel 11 has been divided into two parts, the lower and upper valve barrels 12 and 13; however, the present invention is not limited thereto, and it may be of integral construction. Further, in the present embodiment, the opening and closing valve 23 has its valve stem 24 slidably extended inserted through the support member 15 of the 9lower valve barrel 12 and is thereby liftably supported; however, the valve stem 24 of the opening and closing valve 23 may be integrally attached to the diaphragm and thereby liftably supported by the diaphragm. If the opening and closing valve 23 is liftably supported through the agency of the diaphragm in this manner, no sliding part is present and hence troubles occur less frequently. Further, in the present embodiment, the ball valve 21 has been pressed against the elastic ring 22 mounted on the upper end periphery of the communication port 18; however, the ball valve 21 may be pressed directly against the upper end periphery of the communication port 18 to close the latter.

Claims

1. a stop valve comprising: a valve barrel having an inlet port in the lower region and an outlet port in the upper region thereof and formed with a communication port to establish the communication between a primary chamber of said inlet port and a secondary chamber of said outlet port, an opening and closing valve disposed in said primary chamber and adapted to be lifted and lowered to close said communication port, a ball valve installed in said secondary chamber to open and close said communication port, i a float connected to said opening and closing valve in said secondary chamber, said opening and closing valve being shaped to open with the ball valve mounted on the upper end of the communication port when the opening and closing valve closes said communication port.

2. A stop valve substantially as hereinbefore described Swith reference to figure 1 of the drawings. DATED this 26th day of April 1994. MORITA FIRE PUMP MFG. CO., LTD. By Its Patent Attorneys DAVIES COLLISON CAVE 5071M/PP ABSTRACT A stop valve comprises a valve barrel (11) having an inlet port (14) in the lower region and an outlet port (17) in the upper region thereof and formed with a communication port (18) to establish the communication between the primary chamber of the inlet port and the secondary chamber of the outlet port, an opening and closing valve (23) disposed in the primary chamber and adapted to be lifted and lowered to close the communication port, a ball valve (21) installed in the secondary chamber to open and close the communication o port and a float connected to the opening and closing valve (23) in the secondary chamber. The opening and a closing valve (23) is shaped to interfere with the ball valve mounted on the upper end of the communication hole when the opening and closing valve closes the communication port.