Atmospheric pressure maintenance manhole

Atmospheric pressure maintenance manhole is one type of manhole. Manholes are a general term, divided into carbon steel manholes and stainless steel manholes according to their materials. Manholes are access holes for boilers, storage tanks, sewers, etc. used for personnel to enter and exit for maintenance; For the installation, disassembly, cleaning, and maintenance of internal equipment, people can enter and exit storage tanks, boilers, sewers, etc. through this hole. It is usually installed on the top of storage tanks and containers, and is used in conjunction with air breathing valves and tank washers. The manhole also plays a role in safety and fire prevention, and is a safety device for protecting storage tanks. It is particularly suitable for storing materials in dome shaped atmospheric pressure tanks capped with nitrogen

Manholes can be divided into carbon steel manholes according to their production materials (carbon steel: 20 #, Q23 excellent, ASTM A234, ASTM A105, etc.); Stainless steel manhole (stainless steel: ASTM A403, 1Cr18Ni9Ti, 0Cr18Ni9, 00Cr19Ni10, 00Cr17Ni14Mo2, 304, 304L, 316, 316L, etc.); Alloy steel manholes (alloy steel: 16MnR, Cr5Mo, 12Cr1MoV, 10CrMo910, 15CrMo, 12Cr2Mo1, A335P22, St45.8/III, A10bB)

Manholes are divided into emergency pressure relief manholes, performance stable flame retardant breathing manholes, tank top manholes, tank wall manholes, and core manholes, etc.

Manholes are classified according to their appearance as quick opening manholes, circular manholes, square manholes, elliptical manholes, external manholes, and internal manholes.

Common manholes include: atmospheric pressure manhole, rotary cover plate flat welding flange manhole, rotary cover with neck flat welding flange manhole, rotary cover with neck butt welding flange manhole, vertical hanging cover plate flat welding flange manhole, vertical hanging cover with neck butt welding flange manhole, vertical hanging cover with neck butt welding flange manhole, horizontal hanging cover plate flat welding flange manhole, horizontal hanging cover with neck flat welding flange manhole, horizontal hanging cover with neck butt welding flange manhole, atmospheric pressure rotary handle quick opening manhole, elliptical rotary cover quick opening manhole, rotary arch cover quick opening manhole, atmospheric pressure hand hole, plate flat welding flange hand hole, and neck flat welding flange hand hole. Hole, neck welding flange hand hole, rotary cover neck welding flange hand hole, atmospheric pressure quick opening hand hole, rotary handle quick opening hand hole Rotary cover quick opening hand hole, etc.

Manhole execution standard

HGT21515-2005 atmospheric manhole

HGT 21520-2005 vertical hanging cover with neck flat welding flange manhole

HGT21514-21535-2005

Manhole is a general term for access holes for boilers, storage tanks, sewers, etc. for personnel to enter and exit for maintenance purposes; For the installation, disassembly, cleaning, and maintenance of internal equipment, people can enter and exit storage tanks, boilers, sewers, etc. through this hole. It is usually installed on the top of storage tanks and containers, and is used in conjunction with air breathing valves and tank washers. The manhole also plays a role in safety and fire prevention, and is a safety device for protecting storage tanks. It is particularly suitable for storing materials in dome shaped atmospheric pressure tanks capped with nitrogen. Manholes are divided into emergency pressure relief manholes, performance stable fire-resistant breathing manholes, tank top manholes, tank wall manholes, and core manholes; The manhole is located at the bottom of the tank and is subjected to high liquid pressure. In order to prevent leakage, strict requirements must be placed on the installation quality of the manhole. The flange and cover plate are processed with sealed water lines, and attention should be paid to protection during construction to prevent oil leakage during use. Mark the manhole every time it is removed to avoid misalignment during reinstallation, which may affect its tightness. When installing the nuts on the manhole cover plate, apply even force diagonally in pairs to prevent oil leakage caused by deformation or uneven force on the cover plate