Pressure Reducing Valve Troubleshooting

Troubleshooting methods for Pressure Reducing Valve

The pressure at the inlet and outlet of the pressure reducing valve is the same and the pressure is not reduced. What causes it?

The inlet and outlet pressure of the pressure reducing valve is the same, and the outlet pressure will not change as we turn the pressure handle or tighten the screw. In this case, the pressure is not reduced. If the pressure is not reduced, there is a failure of the pressure reducing valve, and the problems of the pressure reducing valve is not reduced can be divided into 6 reasons:

1. The steam pressure reducing valve has a burr on the main disc or the edge of the body body undercut groove, or there is dirt in the gap between the main disc and the body hole, or the main disc or the hole shape If the position tolerance is excessive, hydraulic clamping will occur, and the main valve disc will be stuck at the position of maximum opening (max). Due to the large opening, the oil will not be decompressed. At this time, the methods of deburring, cleaning and repairing the accuracy of the valve hole and valve disc can be eliminated according to the above situation.

2. Because the main valve disc and the valve hole are too tight, or the valve hole or the valvedisc is pulled during assembly, the valve disc is stuck at the maximum opening position. At this time, a reasonable clearance can be selected. The fitting clearance of J-type pressure reducing valve is generally 0.007～0.015mm. Before fitting, the valve hole can be appropriately ground, and then the valve disc can be equipped.

3. The main valve disc is blocked by short damping holes or valve seat holes, and the automatic adjustment function is lost. The spring force of the main valve pushes the main valve to the maximum opening, which becomes straight and unobstructed, and the inlet pressure is equal to the outlet pressure. The damping holes can be blown through with φ1.0mm steel wire or compressed air, and then cleaned and reassembled.

4. The pressure reducing valve, the damping part with the damping hole is pressed into the main valve disc, and it may be rushed out due to insufficient interference during use. After rushing out, make the pressure in the oil inlet chamber and the oil outlet chamber equal (no damping), and the spool force area is equal, but the oil outlet chamber has a spring, so the main disc is always in the position of maximum opening, so that the outlet The pressure is equal to the inlet pressure. At this time, it is necessary to reprocess the damper with a slightly larger outer diameter and re-press the main disc.

5. Pressure relief valve, the oil drain L is plugged with oil plug when leaving the factory. When this oil plug is used without being unscrewed, it traps the oil in the upper cavity (spring cavity) of the main disc, causing the main disc to be at its maximum opening without decompression. J-type tubular valve is the same. This phenomenon also occurs when the J-plate valve is designed to install the plate without connecting the L port to the oil sump.

6. When the pressure reducing valve and the top cover are installed in the wrong direction, the output oil hole and the oil drain hole will connecte through with each other, resulting in no pressure reduction.

The six troubleshooting methods described above are very practical.