Brief Introduction of Manhole Products Our stainless steel manholes are divided into stainless steel circular manholes without pressure or atmospheric pressure, stainless steel circular Manholes with pressure, stainless steel square manholes and so on. The circular calibers are DN200, DN300, DN400, DN500, DN600, DN700, DN800 and DN900, respectively. Square sizes are 350*450, 530*430 At present, these specifications have been done. It can also be customized according to customer requirements. Our stainless steel manholes are used over tanks, storage and transportation tanks, batching tanks, food tanks, stainless steel tanks and other tanks as the inlet and outlet of materials and inspection and repair ports. Material is divided into: 304 stainless steel, 316L stainless steel, etc.