This standard specifies the basic structure type of man-hole device and head-hole device.
This standard is applicable to the man-hole device and head-hole device of steam boiler with rated steam pressure no larger than 3.82 MPa and hot water boiler.
This standard specifies the basic structure type of man-hole device and head-hole device.
This standard is applicable to the man-hole device and head-hole device of steam boiler with rated steam pressure no larger than 3.82 MPa and hot water boiler.