Vertical lift cover welding flange manhole is widely used in petroleum, electric power, pipeline, container, metallurgy, machinery and other fields, usually installed on the top of pressure tanks or vessels, the product is manufactured according to the national manhole related standards, made of carbon steel or stainless steel

The manhole flange is located on the ring plate, and the diameter is generally 50cm or 60cm. The installation, cleaning and maintenance of the tank can be carried out by personnel who can enter and leave the tank through the manhole or use the manhole for ventilation. Manholes are atmospheric manholes, tank manholes, tank manholes, manholes with core, etc. The manhole is located at the lower part of the oil tank and bears great liquid pressure. In order to prevent leakage, the installation quality of manhole must be strictly required. Sealing waterline is machined on the flange and cover plate, and attention should be paid to protect it during construction to avoid oil seepage in use. Every time when the manhole is removed to mark, so as not to misplace in the installation, affecting the tightness. When installing nuts on manhole cover plate, apply force evenly in pairs diagonally to prevent oil seepage caused by deformation or uneven force of cover plate.

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Manhole flange is installed with a variety of stainless steel empowerments end, as the staff installation, maintenance, cleaning, maintenance access and ventilation! Generally, stainless steel manholes are made of 304 and 316 steel plates as raw materials, or can be made according to customer requirements. The manhole shall be located near the right side of the inlet and outlet pipelines, and shall be as close as possible to the tank chamber for personnel access, maintenance of the tank and ventilation pipe. As the manhole is mounted on the lowest body ring of the tank, seepage prevention is particularly important. It is required that the joint surface of two flanges must be level without flapping and twisting. The reinforcing plate and flange should be cut on the whole steel plate as far as possible without joining together. The sealing ring is machined on the flange and cover plate. Special attention should be paid to protection during construction. Seal with 3mm thick asbestos rubber gasket, no cracking is allowed. When installing the tightening bolt of manhole cover plate, make a diagonal and apply force to prevent the hole cover from deformation.