The DYFJ-A500 valve testing bench is the fourth-generation pressure testing and detection equipment independently developed by Duojia Hydraulics, based on many years of production experience and in accordance with national standards and specifications.
The DYFJ-A500 valve test bench integrates mechanical and electrical, hydraulic systems, pressure testing, and the storage and recycling of liquid mediums. It features comprehensive functions, stable performance, and high levels of automation. It is widely used for sealing surface leakage testing and other performance tests, such as shell strength (pores), on various high, medium, and low-pressure valves with nominal bore sizes of 250-500mm and direct flange connections. Test mediums: water, gas, oil.
The equipment is hydraulically driven and electrically controlled throughout the entire process, exerting no external force on the valves that would affect the test results. This significantly enhances work efficiency and reduces labor intensity, making it an ideal new generation pressure testing and inspection equipment for valve manufacturing companies, users, and maintenance units.
DYFJ-A500 Type Valve Test Bench Working Principle and Structure
The DYFJ-A500 type valve test bench operates by using valve flange positioning and a live pawl to clamp the back of the flange, ensuring that no external forces that could affect the test results are applied during valve testing, complying with the national standard requirements for valve testing.
The equipment is broadly categorized into hydraulic pressure supply systems, electrical control systems, water circulation systems, and various operating devices.
The equipment features a horizontal clamping design with each side of the workbench sealed with a blind plate. The left workbench is equipped with an in/out mechanism, directly driven by a hydraulic cylinder, ensuring uniform force on the valve sealing surface for reliable clamping. (Left) The right workbench can be flipped 90 degrees for easy inspection of gas tightness tests and observation of the valve sealing surface, offering good performance and a simple, compact structure.
Operation Instructions
1. Valve Mounting Method
Select a valve with a nominal bore that matches the equipment model, turn on the power, and start the hydraulic system. Move the left-hand carriage back until it's longer than the valve being tested. Radially move the movable jaw to exceed the outer diameter of the valve flange. Extend the jaw axially to exceed the thickness of the valve flange. Place the valve flange face against the left-hand workbench test blind flange, aligning with the center hole. Radially move the jaw close to the valve flange. Axially move the jaw to make it tightly adhere to the back of the valve flange. At this point, the valve should be securely held and fixed by the left-hand clamping system, ensuring the valve does not fall off.
The sliding bracket on the left advances towards the fixed worktable on the right. The other end of the valve being tested is tightly sealed against the right test blind flange, aligned with the central hollow position. Radially move the clamping jaws close to the valve flange. Axially move the clamping jaws to make the jaws tightly adhere to the back of the valve flange. At this point, the valve should be securely gripped and fixed by the right-side clamping system, with the valve as a whole in a horizontal position.
2. Water Pressure Testing Methods (Bi-directional Inflow, Drainage)
After the valve bracket is installed, refer to the "Clamping Cylinder Pressure Reference Table" to increase the hydraulic clamp force to the required pressure. Adjust the electrical contact pressure gauge (for a 25 kg valve, adjust the pointer to 2.5 MPa). Open the main water intake, left and right water intake valves, close the air intake, drain, and exhaust valves. Start the low-pressure water pump, observe the movement of the water pressure gauge pointer. When the pointer stops rising, it indicates that the valve cavity is fully filled with water. Start the high-pressure water pump; the high-pressure water pump will automatically stop when the water pressure reaches the pressure set on the electrical contact pressure gauge. The equipment enters the water pressure maintenance state.
Upon reaching the pressure-holding time, the valve shows no issues. It should first be opened to release the water pressure inside the valve chamber before removing the valve.
3. Pressure Testing Methods (Bi-directional Intake, Venting)
The equipment does not come with a gas supply. The user must provide a separate gas source. Please consult the manufacturer before using high-pressure gases.
After the valve mount is completed (for example, using pressure air, generally not exceeding 10 kg), open the water and air intake valves, and close the water and air exhaust valves. Close the water and air intake valves when the pressure gauge reaches the highest pressure, and the equipment is in a pressure maintenance state.
Upon reaching the pressure-holding time, the valve is free of any issues. First, open the vent valve to release the pressure inside the valve chamber, then remove the valve.
Cautionary Instructions and Requirements
1. Align the equipment horizontally during installation or secure the base槽钢 with concrete.
2. Use 46-grade anti-wear hydraulic oil (for temperatures below 0°C, use antifreeze 46-grade anti-wear hydraulic oil). The oil level must not be below the oil gauge's lower limit. Regularly check the oil level and hydraulic oil. After one year of use, clean the oil tank and replace the hydraulic oil.
3. Add rust inhibitor to the recirculating water; replace the water promptly when the water quality deteriorates.
4. The equipment work surface should be kept clean, and there should be no debris between the test valve flange and the test pressure blanking plate.
5. Add lubricant to all moving parts of the test bench to ensure clean and smooth operation.
6. Operators must undergo professional training before starting work, adhere to standard procedures, and prioritize safety.
