The DYFJ-C400 valve testing bench is a fourth-generation pressure testing and inspection device independently developed by Duojia Hydraulics on the basis of many years of production experience, in accordance with national standards and specifications.

The DYFJ-C400 valve testing bench integrates mechanical and hydraulic systems, pressure testing, and the storage and recycling of liquid media. It features comprehensive functions, stable performance, and high degree of automation. It is widely used for sealing surface leakage tests and other performance tests, such as shell strength (pinhole), on various high, medium, and low-pressure valves with nominal bore sizes of 200-400mm and direct connection flanges. Test media: water, gas, oil.

The equipment is fully hydraulically driven and electrically controlled, with no external forces affecting the valve test results, significantly enhancing work efficiency and reducing labor intensity. It is an ideal new generation valve pressure testing equipment for valve manufacturing companies, users, and maintenance units.

DYFJ-C400 Valve Test Bench Working Principle and Structure

The DYFJ-C400 valve test bench operates by positioning the valve flange and clamping the back of the flange with live claws, ensuring no external forces affect the test results, in compliance with national standards for valve testing requirements.

Equipment is broadly categorized into hydraulic pressure supply systems, electrical control systems, water circulation systems, and various operating devices.

The equipment is a diving double-tilt type, with each worktable equipped with a sealed blind plate on both the left and right sides. The left worktable features an in/out function mechanism, directly driven by a hydraulic cylinder, ensuring uniform force on the valve sealing surface and reliable clamping. Both left and right worktables can be tilted 90 degrees, and the entire worktable surface can be submerged into the external water tank, allowing the tested valve to be fully immersed in water, facilitating the inspection of air-tightness tests and the observation of the valve sealing surface. It boasts excellent performance, simple and compact structure.

Technical Specifications

Operation Instructions

1. Valve Mounting Method

Select a valve with a nominal bore size corresponding to the equipment model, turn on the power, and start the hydraulic system. Move the left-hand carriage back to a position longer than the valve being tested. Radially move the movable clamp to exceed the outer diameter of the valve flange. Extend the clamp axially to exceed the thickness of the valve flange. Place the valve flange face tightly against the left-hand workbench test blind plate, aligning with the center opening. Radially move the clamp close to the valve flange. Axially move the clamp to ensure it is tightly against 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 will not fall off.

The sliding shelf on the left advances to the right fixed workbench, with the other end of the valve tightly sealed against the right pressure-test blanking plate, aligned with the central opening. Radially move the clamping jaws close to the valve flange, and axially move the jaws to ensure they are flush against the back of the valve flange. At this point, the valve should be securely held by the right-side clamping system, with the entire valve in a horizontal position.

2. Water Pressure Testing Methods (Double-direction Water Inflow and Drainage)

After the valve mount is completed, refer to the "Clamping Cylinder Pressure Comparison Table" to increase the hydraulic clamp's gripping force to the required pressure. Adjust the electrical contact pressure gauge (for example, with a 25 kg valve, adjust the gauge pointer to 2.5 MPa). Open the main inlet, left, and right inlet valves, close the air inlet, drain, and vent 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 pump will automatically stop when the water pressure reaches the pressure set on the electrical contact pressure gauge, and the equipment enters the water pressure holding state.

Upon reaching the pressure-holding time, the valve is free of any issues. First, open the water valve to relieve the pressure inside the valve chamber, then remove the valve.

3. Pressure Testing Methods (Bi-directional Inlet and Exhaust)

The equipment does not come with a gas source. The user must provide their own. Please consult the manufacturer before using high-pressure gases.

After the valve mount is completed (for example, using compressed air, generally not exceeding 10 kg), open the water and air intake valves, and close the water and air release valves. Close the water and air intake valves when the pressure gauge reaches the maximum pressure, and the equipment is in a pressure-holding state.

Upon reaching the pressure-holding time, the valve shows no issues. It should first be opened to release the air pressure inside the valve chamber, then the valve can be removed.

Handling Instructions and Requirements

1. Align the equipment horizontally during installation or secure the anchor slot steel with concrete.

2. Choose 46-grade anti-wear hydraulic oil (use antifreeze 46-grade anti-wear hydraulic oil below 0℃), ensuring the oil level does not fall below the gauge's lower limit. Regularly inspect 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, and replace it 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 pressure test blank flange.

5. Add lubricant to all moving parts of the testing bench to ensure clean and smooth operation.

6. Operators must undergo professional training before starting work, adhere to standardized procedures, and prioritize safety.