The pilot internal discharge pressure relief valve is mainly used on the communication pipe of the medium and low pressure cylinders of the combined heat and power unit, and is installed in parallel with the heating butterfly valve; when the unit is supplying heat with a large load, if the heating load is suddenly lost, the outlet pressure of the medium pressure cylinder will happen instantaneous rise. When the pressure exceeds the set pressure of this valve, the main spool of this valve will quickly open to release the overpressure medium to the inlet of the low-pressure cylinder, thereby protecting the safety of the medium-pressure cylinder.
