Can CO2(R744) heat pump produce cooling and heating by revised valve

Unlike conventional heat pump, CO2(R744) ASHP does not work by revised valve, due the system working pressure is high, there are no such high pressure revised valve available in the market. There are two ways to make CO2 (R744) heat pump offer cool and heat. One way is to use a few one- way valves to instead the revised valve function, changing the refrigerant direction inside the system. Another is to use hydronic system for the cooling and heating, by changing the hydronic flow direction to realize the switching between cooling and heating.