JPH05248566A - Air operated valve - Google Patents

Abstract

PURPOSE:To easily change a Cv value (orifice size) and provide continuous flow state for preventing the growth of a bacteria by constituting an air operated valve to control a fluid flow of a piston and another piston capable of changing the Cv value. CONSTITUTION:This air operated valve has a fluid control piston 3 for controlling a fluid flow, and a fluid control diaphragm 4. The diaphragm 4 is driven and controlled with air pressure from operators 3 and 4 acting on the upper and lower sections of the piston 3. Also, the valve has a Cv value adjustment piston 1 for controlling the position of the piston 3 in open state, and a Cv value adjustment diaphragm 2, respectively for changing the Cv value at a fluid flow position. In case the Cv value is changed, air pressure acting on ports 1 and 2 is adjusted to vertically move the piston 1 and the size of an orifice between the diaphragm 4 and a fluid inlet or outlet is thereby changed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air operated valve.

[0002]

2. Description of the Related Art A conventional air-operated valve has a fluid control piston 3, a fluid control diaphragm 4 as shown in FIG.
have. Next, the operation will be described. FIG. 4 is a double-acting type. When the port 1 is pressurized and the port 2 is opened to the atmosphere, the fluid control piston 3 moves downward in FIG. By moving downward, the fluid control diaphragm 4 also moves downward and closes the fluid inlet. When opening, the port 1 may be pressurized to the atmosphere opening port 2. The fluid control piston 3 has two seals 6.

[0003]

In this conventional air operated valve, it was necessary to select the size of the orifice (hereinafter referred to as the Cv value) according to the flow rate used. Further, since the valve operates only when the valve is opened or closed, if a fluid is always allowed to flow to the point of use as a countermeasure against pure water bacteria, it is necessary to add a bypass line as shown in FIG. Further, there is a problem that it is impossible to completely eliminate the region where the flow velocity is zero.

[0004]

The air operated valve of the present invention comprises a piston for controlling the flow of fluid and a piston for determining the stop position when the fluid control piston is opened.

[0005]

The present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of the first embodiment of the present invention. It has a fluid control piston 3 for controlling the flow of fluid, a fluid control diaphragm 4, which pressurizes port 3, port 4,
Controlled by opening to the atmosphere. Further, in order to change the Cv value of the portion in which the fluid flows, it has a Cv value adjusting piston 1 and a Cv value adjusting diaphragm 2 which control the position when the fluid control piston 3 is opened.

Next, the operation will be described. When the fluid control piston 3 opens and closes the orifice with a full stroke, the port 1 may be opened to the atmosphere, the port 2 may be pressurized, and the ports 3 and 4 may be pressurized and opened to the atmosphere. When opening the orifice, the port 4 is pressurized and the port 3 is opened to the atmosphere. When closing the orifice, port 4
Is opened to the atmosphere and port 3 is pressurized.

Next, the case where the Cv value is changed and used will be described with reference to FIG.

By applying pressure to port 1 and opening port 2 to the atmosphere from the state of (A), the Cv value adjusting piston moves downward by S. As a result, the orifice becomes narrower by S. In this state, if the ports 3 and 4 are pressurized and opened to the atmosphere, the orifice can be changed, that is, the Cv value can be changed. (C) shows this state.

Next, the following measures can be taken to prevent bacteria such as pure water.

Port 4 is pressurized, port 3 is left open to the atmosphere, port 2 is pressurized, port 1 is open to the atmosphere, port 1 is next pressurized while fluid is flowing, and port 2 is open to the atmosphere. Then, the fluid control piston advances by the stroke of S and stops due to the difference in the pressure receiving areas (B). At this time, since the orifice is opened by (LS), the fluid flows. At this time, the Cv value of the orifice must be minimized. As a result, the fluid flows through the air-operated valve to the outlet, and the flow velocity does not become zero, so that the growth of bacteria can be prevented.

Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 2 is a sectional view of the second embodiment of the present invention. In addition to the first embodiment, the air operated valve of the second embodiment is provided with a Cv value adjusting nut 7 so that the stroke of the Cv value adjusting piston 1 can be adjusted. This allows the Cv value to be set arbitrarily.

[0012]

As described above, the present invention adds a piston for stroke adjustment so that the stroke of the piston for controlling the flow of fluid can be adjusted, and the adjustment piston operates at any timing. Since it is possible to do so, the Cv value of the orifice through which the fluid passes can be changed with one air-operated valve, and it is also possible not to close the orifice completely and use it with the fluid always flowing. It has the effect of preventing the reproduction of bacteria.

[Brief description of drawings]

FIG. 1 is a sectional view of a first embodiment of the present invention.

FIG. 2 is a sectional view of a second embodiment of the present invention.

FIG. 3 is an operation explanatory diagram of the present invention.

FIG. 4 is a sectional view of a conventional air operated valve.

FIG. 5 is a piping diagram when a bypass is added to the inlet and the outlet to prevent bacteria from growing with a conventional air operated valve.

[Explanation of symbols]

 1 Cv value adjusting piston 2 Cv value adjusting diaphragm 3 Fluid control piston 4 Fluid control diaphragm 5 Stopper 6 Seal 7 Cv value adjusting nut

Claims (1)

[Claims] 1. An air-operated valve for controlling the flow of fluid, comprising a piston for controlling the fluid and a piston capable of changing the size of an orifice.