jug
甁 centers on a container for liquids: a jug or jar. It is a specific vessel shape, not a general container word.
甁 combines 瓦 (earthenware) with 幷, which likely contributes the sound. Together they indicate a ceramic jug.
The right side 瓦 means earthenware, and the left side 幷 looks like a container with a lid. Picture a ceramic jug made from clay.
For ヘイ, imagine a heavy jug full of water: heavy -> ヘイ, and the jug is so heavy you can barely lift it.