When installing the nuts on the manhole cover, apply force evenly in pairs, diagonally, to prevent oil leakage caused by cover deformation or uneven force.
Because the stainless steel manhole is located at the bottom of the oil tank, it is subjected to high liquid pressure. Therefore, strict requirements must be placed on the installation quality of the manhole to prevent leakage.
Mark the manhole each time it is removed to avoid misalignment during reinstallation, which could affect the tightness. The flanges and cover plates have machined sealing water lines; these should be protected during construction to prevent oil leakage during use.
