Air Source Heat Pump After Sales Article: Analysis of Typical Four-way Valve Failure CasesThe four-way valve is the most important joint part of the air source heat pump. After installing the air source heat pump, this part is also the most problematic part. LEOMON will explain the reasons why the four-way valve often fails. Hope you can better use the four-way valve.
The solenoid valve coil is damaged, and the pilot valve does not work; the spool valve inside the four-way valve is stuck by impurities in the system (oxide scale, debris, or degraded grease), and some of it can be solved by external knocking; the valve body is impacted by external force The valve body is deformed, and the spool valve is stuck and cannot be moved; the internal liquid strike of the system causes the spool valve guide frame to break, the end cover is damaged and deformed, and it cannot be reversed; the internal clearance of the four-way valve is too large, and the valve seat is slightly burned out when the valve seat is welded. The leakage exceeds the standard , Causing air leakage, balance the pressure at both ends of the spool valve, and fail to push the spool valve to change direction; the system pressure causes the main slider of the four-way valve to break, causing the main slider to fail to change direction; the internal cavity of the pilot valve is dirty, causing the pilot valve Cannot work; the capillary of the pilot valve is blocked or broken, causing the reversing pressure difference to not be accurately transmitted to the main valve body to complete the reversal; other reasons can not establish the pressure difference reversal.
The compressor and the four-way valve blow together, indicating that the high-pressure and high-temperature exhaust has entered the low-pressure suction. Due to the heating of the low-pressure suction temperature, the discharge temperature of the compressor will be higher, the exhaust pipe will heat up, and the operating temperature of the compressor is also Very high.
Compressor air flow: The suction and exhaust temperature is very high, and the suction pressure is also higher than normal. Because the compressor's air valve (valve) or floating sealing plate is not tightly closed, part of the exhaust pressure is returned to the low pressure chamber, so the exhaust Air pressure (high pressure) will not rise, it will be lower than normal pressure, and operating current will be lower than normal.
Four-way valve string gas: After being compressed, high-pressure and high-temperature gas flows back to the compressor or the low-pressure end in the low-pressure pipe through the four-way valve. Touch the four-way valve to take over, but the pipe that should be cold heats up. It should be affirmed that the actual work done by the compressor has increased. As the suction pressure of the compressor increases, it is equivalent to an increase in the load of the compressor. Because the compressor does not have internal gas flow, the operating current must increase, and the high pressure pressure and discharge temperature after compression will be higher than normal. The value is high.
The four-way valve plays an important input and output function. After installing the air source heat pump, do not move the four-way valve easily to avoid loosening or air leakage.