What do J, W, F, RM and RMH in the water supply and drainage pipeline stand for respectively?

J: domestic water supply pipe, and J is the initials of "give" in "water supply pipe";

W: sewage pipe, where W is the initials of "sewage pipe";

RM: heat medium water supply pipe, RM is the initials of "heat medium";

RMH: heat medium return pipe, RMH is the initials of "heat medium return".

Extended data:

Test method of unpressurized drainage pipeline;

1, close the main water valve. (that is, the water pipe switch in front of the water meter)

2. Turn on the faucet in the room for 20 minutes, and then turn off all the faucets after ensuring that there is no dripping water.

3. Turn off the water inlet switch of toilet water tank, washing machine and other equipment with water storage function.

4. Open the main water valve.

5. Open the main valve for 20 minutes and check whether the water meter moves, including walking slowly. If there is any movement, it is leaking. If you don't move, you'll be fine.