Answer:
✔ Water hammer - uses a water seal to prevent sewer gases from entering the occupied areas of the home.
✔ Solder - a metal alloy that is melted to create a fused joint between metal pieces.
✔ escutcheon - flange installed around a pipe to conceal pipe penetrations through a wall, floor, or ceiling.
Explanation:
(Note: The other part of the attachment isn't visible)
The water hammer is known to be used in piping system and it is used to control the flow of liquids or gases. The solder is used during soldering. It is a soft metal alloy which is melted to join metal pieces together.
The escutcheon is actually used to conceal some functioning. It is a flange which can be installed around a pipe in order to conceal it.