Heat transfer oil circulation

Play a big round-robin. The purpose of the cold-cycle test is to check whether there is any backpressure in the entire heating system, to identify any leaks in equipment, pipes, valves, etc., and to determine whether the flow rate and head capacity of the circulation pump meet the operational requirements. Due to the high viscosity of cold oil, the pressure difference between the inlet and outlet of the heat carrier furnace is relatively large, and the flow resistance in the piping system is also high. Each circulation pump should be started and tested in turn, allowing the cold oil to circulate within the system for 6 to 8 hours. During the cold-state cycle, it is also necessary to frequently open the vent valve to release residual air, and monitor and record the readings from pressure gauges, thermometers, ammeters, etc. at various points. Pay attention to recording data such as the current of the circulation pump, the outlet pressure of the circulation pump, and the pressure difference between the inlet and outlet of the organic heat carrier furnace. Additionally, check whether the oil pump is operating smoothly and whether the bearing seals are in good condition. Remove and clean the filter: During the cold-circulation phase, various impurities in the system as well as residues in the heat transfer fluid are filtered out by the filter located before the oil pump, as the cold oil circulates. Once the circulation is complete, the filter should be removed to eliminate all dirt from inside it and on its filter elements.

Do all of them need to have their vent valves opened to release residual air?

During operation, the system must intermittently open the vent valve to release residual air, similar to the venting in home heating pipes and radiators.

All locations where vents are provided for the pipes and equipment through which the heat transfer oil flows.