| 1 | Valve opening and closing failure | The packing is too tight and the gland is skewed | Adjust the tightness of the stuffing box bolts and the gland pressure |
| Opening and closing parts fall off | Replacement of valves |
| Bent valve stem, damaged valve stem threads, scale accumulation | Straighten the valve stem, repair the valve stem threads and descale |
| The closing force of the gate valve is too large or the valve stem expands due to heat | Tap the valve body flange while turning the handwheel |
| The bracket bearing is loose and presses against the hand wheel | Re-fix the bearing gland |
| Cold season freezing | Steam properly heated valve |
| 2 | Packing leakage | Packing gland loose | Tighten the packing gland |
| Insufficient filling | Add filler |
| Filler technical performance does not meet | Replacement of packing |
| The valve stem is rough, bent, and has axial grooves | Improve surface finish, straighten valve stems, and repair grooves |
| 3 | Middle flange leakage | Uneven tightening of flange bolts | Consistent bolt torque |
| The technical performance of the padding material does not meet the requirements | Replace the bedding |
| Flange sealing surface is defective | Repair sealing surface |
| 4 | Valve internal leakage | Foreign matter falls into the valve and sticks to the sealing surface | Remove foreign matter |
| The spherical surface at the end of the valve stem is deformed or hanging | Repair the sphere |
| Wear of the opening mechanism of the double-disc gate valve | Repair the expansion mechanism |
| Sealing surface damage | Training |
| 5 | No condensation | The valve on the steam pipeline before the valve is damaged or not opened | If the valve is damaged, it needs to be repaired. If the valve is not open, it should be opened. |
| The elbow of the steam pipeline before the valve is blocked | Clean the dirt in the pipeline, and the pipeline bending should meet the requirements |
| The filter is clogged with dirt | Clean the filter regularly |
| The trap is full of dirt | Repair the filter and clean the dirt inside the valve |
| The control room is filled with air and non-condensable gas, so the valve cannot be opened. | Open the valve cover to discharge non-condensable gas |
| The valve on the bypass pipe and the sewage pipe before the valve is leaking | Repair or replace valve |
| 6 | Exhaust steam | The valve cover is not tight, the pressure in the control chamber cannot be established, and the valve plate cannot be closed. | Tighten the valve cover or replace the valve disc |
| The valve seat sealing surface and valve disc are worn | Regrind, if it cannot be repaired, replace it |
| There are impurities between the valve chamber and the valve plate | Open the valve cover to remove debris |
| 7 | Drainage continues | Drastic increase in water discharge in steam pipes | The boiler sometimes bubbles and sends out a large amount of water. A steam-water separator should be installed to solve this problem. |
| The selected steam trap displacement is too small | The problem should be solved by replacing the steam trap with a large drainage capacity or connecting it in parallel. |
