The DYFJ-A400 valve testing bench is the fourth-generation pressure testing and inspection equipment independently developed by Duojia Hydraulics, based on many years of production experience and in accordance with national standards and specifications.
The DYFJ-A400 valve test bench integrates mechanical and electrical systems, hydraulic systems, pressure testing, and the storage and recycling of liquid media into one unit, featuring comprehensive functions, stable performance, and high automation. It is widely used for sealing surface leakage testing and various performance tests such as shell strength (pores) on 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 powered by hydraulic drive and electric control, with no external forces affecting the valve's test results, which significantly enhances work efficiency and reduces labor intensity. It is the ideal new generation of pressure testing and inspection equipment for valve manufacturing companies, users, and maintenance units.
DYFJ-A400 Type Valve Test Bench Working Principle and Structure
The DYFJ-A400 valve test bench operates by positioning the valve flange and clamping the back of the flange with movable claws, ensuring no external forces that could affect test results are applied during valve testing, in compliance with national standard valve testing requirements.
Equipment is generally divided into hydraulic pressure supply systems, electrical control systems, water circulation systems, and various operating devices.
The equipment is a horizontal clamping type with sealed blind plates on both sides of the worktable. The left worktable features an in-and-out mechanism driven directly by a hydraulic cylinder, ensuring uniform force on the valve sealing surface and reliable clamping. (Left) The right worktable can be flipped 90 degrees for convenient checking of gas tightness tests and observation of the valve sealing surface, boasting good performance and a simple, compact structure.
Operation Instructions
1. Valve Mounting Method
Select a valve with a nominal diameter that matches 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 adjustable clamp to a diameter larger than the outer diameter of the valve flange. Extend the clamp axially to a length greater than the thickness of the valve flange. Place the valve flange face against the left-hand workbench and align it with the center opening. Radially move the clamp close to the valve flange, and axially move the clamp to ensure it is tightly against the back of the valve flange. At this point, the valve should be securely clamped and fixed by the left-hand clamping system, ensuring that the valve will not fall off.
The sliding bracket on the left advances towards the fixed worktable on the right. The other end of the valve to be tested is tightly sealed against the right pressure test blind flange, aligned with the center empty space. 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 clamped and fixed by the right-side clamping system, with the valve in an overall horizontal position.
2. Water Pressure Testing Methods (Double-way Water Inflow, Water Discharge)
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, for a 25 kg valve, adjust the gauge pointer to 2.5 MPa). Open the main water intake, left and right water intake valves, close the air intake, drain, and vent valves. Start the low-pressure water pump, observe the movement of the 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 maintenance state.
Upon reaching the pressure holding time, there are no issues with the valve. First, open the drain valve to release the water pressure inside the valve chamber, then remove the valve.
3. Pressure Testing Methods (Bi-directional Intake, Venting)
The equipment does not come with a gas source. The user must provide a separate gas source. Please consult the manufacturer before using high-pressure gases.
After the valve fixture is completed (for example, using pressure air, generally not exceeding 10 kg), open the inlet and air inlet valves, and close the drain and air release valves. Close the inlet and air inlet valves when the pressure gauge reaches the highest pressure, and the equipment is in a pressure-holding state.
Upon reaching the pressure-holding time, the valve is problem-free. First, open the vent valve to release the pressure inside the valve cavity, then remove the valve.
Caution and Requirements for Use
1. Ensure the equipment is level during installation or secure the anchor slots with concrete.
2. Use 46-grade anti-wear hydraulic oil (use anti-freeze 46-grade anti-wear hydraulic oil below 0℃), ensuring the oil level does not fall below the 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, 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 test pressure blanking plate.
5. Add lubricant to all moving parts of the test bench to maintain clean and smooth operation.
6. Operators must undergo professional training before assuming their positions, adhere to standard procedures, and prioritize safety.
