Na nso nso a, anyị mepụtara a bi-directional wafer urukurubụba valvụ maka Japanese ahịa ， na-ajụ na-ekesa jụrụ jụrụ mmiri, okpomọkụ + 5 ℃.

Onye ahịa na-ejibu valvụ unidirectional urukurubụba valvụ, mana enwere ọtụtụ ọnọdụ chọrọ n'ezie valvụ urukurubụba bi-directional, yabụ onye ahịa anyị gwara anyị ka anyị weghachi valvụ wafer nru ububa bi-directional n'ọnọdụ ndị a na-agbanweghị ihu na ihu.

Ka anyị nwesịrị mkparịta ụka ngalaba nka nka na TTHT, anyị kpebiri iji mbụ unidirectional sealing ebu iji hazie valvụ nru ububa akara bi-directional. N'ihi ya, anyị nwere ihe ịga nke ọma, PN25 ezigbo nrụgide azụ 1: 1.