1 Scope
This standard specifies the types, basic parameters, dimensions, technical requirements and relevant service requirements of welding neck flange manholes with davit to vertical cover made of carbon steel and low-alloy steel.
This standard is applicable to welding neck flange manholes with davit to vertical cover, of which the nominal pressure PN is 2.5~6.3MPa, the working temperature and the corresponding maximum non-impact working pressure are limited within the range specified in Table 3-2 according to material category.
2 Normative References
GB/T 41-2000 Hexagon Nuts - Product Grade C
GB/T 95-2002 Plain Washers - Product Grade C
HG 20595-1997 Steel Pipe Welding Neck Flanges (European System)
HG 20601-1997 Steel Pipe Blank Flanges (European System)
HG 20606-1997 Nonmetallic Flat Gaskets for Steel Pipe Flanges (European System)
HG 20607-1997 PTFE Envelope Gasket for Steel Pipe Flanges (European System)
HG 20608-1997 Flexible Graphite Compound Gaskets for Steel Pipe Flanges (European System)
HG 20609-1997 Metal Envelope Gaskets for Steel Pipe Flanges (European System)
HG 20610-1997 Spiral Wound Gaskets for Steel Pipe Flanges (European System)
HG 20613-1997 Fasteners for Steel Pipe Flanges (European System)
HG/T 21514-2005 Type and Technical Specifications of Steel Manhole and Handhole
3 Types, Basic Parameters and Dimensions
The types, basic parameters and dimensions of manhole are detailed in Figure 3 and Tables 3-1~3-3.
Figure 3 Manhole Type
Table 3-1 Detail List
