当油箱内正压或负压力过大时释压活门可防止机翼结构损坏。
A When there are too many positive or subtractive pressure in the fuel tanks the pressure relief valve eliminates damage to the wing structure.
B when there is too much plus or minus pressure in the fuel tanks, the pressure relief valve previews damage to the wing structure.
C The pressure relief valve prevents damage to the wing structure when there is too much positive or negative pressure in the fuel tanks.