Standard for stainless steel manholes

At present, the commonly used stainless steel manhole standards are HG/T 21515-2005 atmospheric pressure manhole, HG/T 21516-2005 swivel cover plate type flat welding flange manhole, HG/T 21517-2005 swivel cover with neck flat welding flange manhole Hole, HG/T 21518-2005 swivel cover with neck butt welding flange manhole. The specific selection conditions are detailed in each standard, which is mainly determined according to your use environment and requirements.