drinking water.

fitting for portable water system.

I think it should be translated to "potable water equipment".

As far as I know, fitting is refered to bends, sockets, tees, taps, mini-ball valves, all the small parts that we use to install the piping works.

Here is my opinion:
In foreign countries, people drink water directly from water distribution system. The water quality must meet hygenic demand.
In China, we have a good custom to drink hot water( for tea).
Portable water equipment is used in crisis, for example, in refugee camp or disaster area(flooding). It is one kind of emergency water-supply equipment.
Some water supply companies will provide water bag or battled water in free to their customers, in condition that water supply has been shut because of network maintence or pipe burst.
I am not sure what I said. We can exchange with understanding and respect in this forum.
Thank you!

i dont know

是否 pipe drinking equipment?

depurative water supply

drinking water

Potable water or drinking water should all fine.

potable water 比较专业一点