First, the heating system is not hot
If all the user systems in the heating system are not hot, the reason must be in the boiler room; if some users are not hot, the reason may be in the boiler room or on the external thermal network. If the boiler output may not meet the requirements or the flow and head of the circulating water pump are not enough, the external heat pipe network may leak or block; if the riser is not hot, the temperature and pressure of the heat medium at the heat inlet may not reach the design. Requirements, it may be that the exhaust device is not working, resulting in air blockage; if the radiator is not hot, it may be blocked by the branch pipe or the system exhaust is not smooth, or the steam trap may be leaking.
Second, the failure of the outdoor heat pipe network
Possible reasons for pipe rupture are:
1) Poor pipe material or poor welding quality.
2) The compensator's lack of ability is not enough or does not work.
3) The pipe is frozen.
4) A water hammer occurs inside the pipe.
5) The pipe support sinks.
6) The sliding support is rusted and cannot slide.
2. Pipe blockage
Possible reasons for blocked or partially blocked pipes are:
1) The dirt carried by the heat medium is deposited in the gate.
2) The corrosive material on the inner wall of the metal pipe is peeled off and accumulated in the pipe.
3) Poor water quality and serious scale.
4) After the sealing packing of the valve or pipe connection part is damaged, transfer it into the pipe.
3. Heat medium leakage at the pipe joint
Possible reasons for leakage of heat medium are:
1) The gasket between the flanges fails, ages and breaks.
2) The flange sealing surface is not parallel when installed, and the flange surface has pits or nicks.
3) The connecting bolts are not tightened or tight.
4. Compensator failure
Natural compensators, release compensators, bellows compensators, etc. rarely fail, and only the sleeve compensator has more faults. The main faults are:
1) Leakage is caused by the failure of the filler aging and the packing box is not tightened.
2) The inner cylinder is bitten because the packing is too tight, the inner and outer sleeves are eccentric, and the damage of one side of the compensator causes the straight pipe section to sag.
3) The compensation capacity is not enough. The reason is that the design is not properly selected, and the installation length of the stud bolt on the compensator is not enough.
4) The inner cylinder is dislodged due to damage to the device on the compensator that prevents the inner cylinder from coming out.
It can be processed according to the cause of the malfunction.
Third, the user's heating system failure
1. There is heat medium leakage at the threaded joint
Possible reasons for this are:
1) The threaded pipe itself is of poor quality. If there are blisters or cracks, it is not found during installation.
2) The threaded connection is not tightened.
3) Improper selection of sealing materials or aging failure.
2. Pipe leaks
The main reasons for pipeline leakage are:
1) Due to freezing and rupture, it often occurs in the door pipe near the outer door or through the pipe in the unheated room.
2) The pipe is worn out, mainly on the uncased wall or through the floor pipe.
3) The pipe is corroded and perforated, oxygen corrosion occurs inside the pipe, and the insulation material outside the pipe is corroded by sulfide or groundwater.
3. Failure of the pressure reducing valve
1) The pressure reducing valve is blocked because the control passage is blocked and the piston is rusted at the highest position.
2) The pressure reducing valve is straight through and cannot adjust. The cause may be that the main valve spring is broken or malfunctioning, the diaphragm is damaged, the sealing surface of the valve seat is notched or dirty, the main valve stem is stuck, and the valve of the pulse valve is stuck.
3) The pressure cannot be adjusted after the pressure reducing valve. The reason may be that the adjusting spring is out of order, the piston ring is locked in the groove, and the cylinder is filled with condensed water.
4) The pressure fluctuation after the pressure reducing valve is large, the reason is mostly the advance, and the flow rate of the heat medium of the pressure reducing valve fluctuates greatly.
4. Steam trap failure
1) Undrained. If it is a float type steam trap, it may be that the pressure difference between the front and the rear of the steam trap is too large, the float is too light; the trap hole is too large, the valve tip of the water stop valve is rusted on the valve hole; the valve hole or passage is blocked, the valve stem Or the sleeve is stuck.
The reason for the heat-powered steam trap, which is cold and not drained, is that steam or water does not enter the steam trap, or the steam trap is filled with dirt. The reason for heat and non-drainage may be that water does not enter the steam trap at all.
2) Leakage. The reason why the steam trap is leaking may be a problem with the steam trap itself, or it may be a problem with the steam trap valve. For thermodynamic steam traps, valve seat and valve plate wear are the main causes of steam leakage.
3) The displacement of the steam trap is too small. This happens mostly in the pontoon trap, where the steam trap mechanism moves frequently and the tip is worn. The possible cause is that the dirt deposited in the pontoon reduces the volume of the pontoon, the floating and sinking is frequent, or the pontoon is rusted and the scale increases the weight.
Fourth, major accidents in heating
For the user's indoor heating system, the pressure in the pipeline suddenly rises, causing the hot gas rupture of the cast iron radiator to be a big accident; the external pipe network, the most serious accident is the serious rupture of the pipeline, the large amount of heat medium leakage, the most serious accident mainly occurs in the boiler In the room, the most dangerous of the boiler explosion.
Preventing major accidents in the heating system, avoiding complete interruption of heating, serious equipment damage or casualties is a very important task in the management of heating systems.