A pilot-operated directional valve for an easy-to-maintain pneumatic dual diaphragm pump

Abstract

This invention proposes a pilot-operated reversing valve for a pneumatic dual diaphragm pump that is easy to maintain. It includes a valve body, a left end cover and a right end cover, a first sliding sleeve, a second sliding sleeve, a sliding rod that can slide back and forth within the first and second sliding sleeves, a valve disc mounted on the sliding rod and sliding together with it, a reversing plate that forms a planar sliding dynamic seal with the valve disc, a left contact rod and a right contact rod respectively disposed on the left and right end covers, and a first chamber, a second chamber, and a third chamber for internal travel. The sliding rod is divided into two or more pieces along its length, the length of each piece not exceeding the length of the reversing plate. This invention eliminates the need to remove the diaphragm pump from the infusion line or completely disassemble the diaphragm pump from the outside in during maintenance of vulnerable components, greatly simplifying the disassembly and assembly process and improving maintenance efficiency.

Claims

1. A pilot-operated directional valve for a pneumatic double diaphragm pump that is easy to maintain, characterized in that: it includes a valve body, a left end cover and a right end cover installed at the left and right ends of the valve body, a first sliding sleeve and a second sliding sleeve installed in the valve body, a sliding rod that can slide back and forth within the first sliding sleeve and the second sliding sleeve, a valve disc installed on the sliding rod and sliding together with the sliding rod, a directional plate that contacts the valve disc to form a planar sliding dynamic seal, and a left contact rod and a right contact rod respectively disposed on the left end cover and the right end cover; a first chamber formed by the left end cover, the inner hole of the first sliding sleeve, and the left side of the sliding rod; a second chamber formed by the sliding rod, the first sliding sleeve, the second sliding sleeve, the valve body, and the directional plate; and a third chamber formed by the right side of the sliding rod, the inner hole of the second sliding sleeve, and the right end cover; wherein the sliding rod is divided into two or more pieces along its length, and the length of each piece is not greater than the length of the directional plate.

2. The easy-to-maintain pneumatic double diaphragm pump pilot-operated directional valve as described in claim 1, wherein, The bottom of the second chamber is provided with a base plate that supports the slide rod.

3. The easy-to-maintain pneumatic double diaphragm pump pilot-operated directional valve as described in claim 1, wherein, The slide bar consists of three parts: a left slide bar, a middle slide bar, and a right slide bar.

4. The easy-to-maintain pneumatic double diaphragm pump pilot-operated directional valve as described in claim 1, wherein, The reversing plate is provided with a first working hole, an exhaust hole and a second working hole in sequence; the first chamber is provided with a first connecting hole and is connected to the first working hole; the third chamber is provided with a second connecting hole and is connected to the second working hole; the exhaust hole on the reversing plate is connected to the main exhaust hole of the diaphragm pump.

5. The easy-to-maintain pneumatic double diaphragm pump pilot-operated directional valve as described in claim 4, wherein, The first chamber is located on the left side of the slide rod, and this chamber is connected to the first working hole on the reversing plate through the first connecting hole; the second chamber is connected to the compressed air source and is filled with compressed air; the third chamber is located on the right side of the slide rod, and this chamber is connected to the second working hole on the reversing plate through the second connecting hole; when the slide rod moves to a certain position under the push of the diaphragm, the first chamber and the third chamber located on the left and right sides of the slide rod, respectively, one of which is filled with compressed air and the other is filled with compressed air, and a pressure difference is quickly formed on the left and right sides of the slide rod, which pushes the slide rod to quickly change direction.

6. The easy-to-maintain pneumatic double diaphragm pump pilot-operated directional valve as described in claim 5, wherein, The second working hole (or the first working hole) on the reversing plate is also connected to the control chamber of the air main valve of the diaphragm pump. As the pilot reversing valve reverses, the second working hole (or the first working hole) alternately fills and discharges compressed air into the control chamber of the air main valve, that is, sends a reversing signal to the air main valve to drive the air main valve to reverse.

7. The easy-to-maintain pneumatic double diaphragm pump pilot-operated directional valve as described in claim 6, wherein, The valve disc and the reversing plate are made of ceramic material. The valve disc slides back and forth on the reversing plate under the drive of the slide rod, and a planar sliding dynamic seal is formed between the two.

8. The easy-to-maintain pneumatic double diaphragm pump pilot-operated directional valve as described in claim 7, wherein, The slide bar is provided with a first Y-ring and a second Y-ring; the valve disc is provided with a concave hole.

9. The easy-to-maintain pneumatic double diaphragm pump pilot-operated directional valve as described in claim 2, wherein, The base plate is made of ceramic material.

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