Patent ID: 7284568

Claim:
In a safety valve unit capable of being adjusted in cracking pressure, the improvement wherein an adjustment in cracking pressure of said valve unit is performed from the outside without disassembling any part of said valve unit; wherein said valve unit is provided with a rotary barrel member ( 1 ), incorporated in which barrel member ( 1 ) is a cracking-pressure adjusting portion ( 4 , 5 , 6 , 7 and 8 ), wherein a movable spring support ( 4 ) of said cracking-pressure adjusting portion ( 4 , 5 , 6 , 7 and 8 ) is driven by said barrel member ( 1 ) to adjust said valve unit in cracking pressure; and said barrel member ( 1 ) is provided with a female screw portion ( 2 ); said female screw portion ( 2 ) of said barrel member ( 1 ) is threadably engaged with a male screw portion of said movable spring support ( 4 ), so that said movable spring support ( 4 ) is axially and linearly displaced when said barrel member ( 1 ) is rotated in adjusting said valve unit in cracking pressure.