This standard specifies the classification and technical conditions of stainless steel manholes in HG21595~HG21604-1999 standards. This standard applies to stainless steel manholes and handholes used as outlets and inlets on containers in the chemical and petrochemical industries. The nominal pressure is normal pressure: 0.6~4.0MPa, and the working temperature is -20~300℃. HG 21594-1999 Classification and Technical Conditions of Stainless Steel Manholes and Handholes HG21594-1999 Standard Download Decompression Password: www.bzxz.net

Classification and technical conditions of stainless steel manholes and handholes HG 21594-1999
1 Subject content and scope of application
This standard specifies the classification and technical conditions of stainless steel manholes and handholes in HG21595~HG21604-1999 standards.
This standard applies to stainless steel manholes and handholes used as outlets and inlets on containers in the chemical and petrochemical industries. The nominal pressure is 0.6~-4.0MPa at normal pressure and the working temperature is 20~~300℃.
Containers similar to those in the chemical and petrochemical industries can also adopt this standard.
2 Reference standards
The provisions contained in the following standards are used in this standard to constitute the provisions of this standard. When the following standards are used after the publication of this standard, the latest version shall prevail. National Quality and Technical Supervision
GB 150
JB/T 4735
GB/T 14976
GB/T 3280
GB4237
GB 711
GB3274
GB6654
GB 699
GB5574
GB/T 3985
GB 3103.1
GB 5779. 1
GB 5779. 2
GB 196
JB/T 4709
《Safety Technical Blue Inspection Code for Pressure Vessels》
《Welded Steel Atmospheric Pressure Vessels》
《Seamless Stainless Steel Pipes for Fluid Transportation》bzxz.net
《Hot-rolled Stainless Steel Plates》
《Hot-rolled Thick Plates and Strips of High-quality Carbon Structural Steel》
《Hot-rolled Thick Plates and Strips of Carbon Structural Steel and Low-alloy Structural Steel》
《Steel Plates for Pressure Vessels》
《Carbon Structural Steel》
《Technical Conditions for High-quality Carbon Structural Steel》
《Industrial Vulcanized Rubber Sheets》
《Asbestos Rubber Sheets》
《Fastener Tolerances - Bolts, Screws and Nuts》
《Fastener Surface Defects - Bolts, Screws and Studs - General Requirements》
《Fastener Surface Defects - Nuts - General Requirements》
Requirements》
"Basic Dimensions of Ordinary Threads"
"Tolerances and Fits of Ordinary Threads"
"Welding Code for Steel Pressure Vessels"
JB4730
JB4726
HG20581
"Basic Types and Sizes of Bevels for Gas Welding, Manual Arc Welding and Gas Shielded Welding"
"Basic Types and Sizes of Bevels for Arc Welding"
"Non-destructive Testing of Pressure Vessels"
"Carbon Steel and Low Alloy Steel Forgings for Pressure Vessels"
"Materials Selection Regulations for Steel Chemical Containers" HG2059220614"Steel Pipe Flanges, Gaskets and Fasteners (European System)" 5
3 Classification
The classification of stainless steel manholes, sealing types and series parameters shall be as specified in Table 3-1. Table 3-1
Stainless steel
Swing cover
Stainless steel
Diameter Sealing surface type
(Full plane)
(Raised surface)
(Concave and convex surface)
Standard number
HG21595
HG21596
Swing cover
Stainless steel
Swing arch| |tt||Cap quick-open
Stainless steel
Stainless steel
Continued Table 3-1
Diameter Sealing surface type
(Raised face)
(Face)
(Raised face)
(Convex face)
(Face)
(Concave and convex face)
Standard push number
HG21596
HG 21597
HG21598
Stainless steel
Stainless steel
Continued Table 3-1
Sealing surface type
(Raised face)
(Concave face)
(Raised face)
(Convex face)
Standard number
HG21598
HG21599
Stainless steel
Stainless steel
Stainless steel
Continued Table 3-1
(MPa)(mm)
Sealing surface type
(Raised face)
(Concave and convex face)
(Raised face)
(Face)
Standard number
HIG 21599
HG21600
HG 21601
Stainless steel
Swing cover
Stainless steel
Continued Table 3-1
Diameter Sealing surface type
(MPa)(mm)
Raised face）
(Concave face）
(Raised face)
(Concave and convex face)
(Raised face)
Standard number
HG21 602
HG21603
Stainless steel
Continued Table 3-1
(MPa）
Diameter Sealing surface type
(groove surface)
Standard number
HG21604
4 Technical conditions
4.0.1 The manufacture of stainless steel manholes and handholes shall comply with the requirements of the drawings and the provisions of this standard. Normal pressure stainless steel manholes and handholes shall be manufactured, tested and accepted in accordance with JB/T4735 "Steel Welded Normal Pressure Vessels", and non-normal pressure stainless steel manholes and handholes shall be manufactured, tested and accepted in accordance with GB150 "Steel Pressure Vessels" and "Safety Technical Supervision Regulations for Pressure Vessels" of the State Quality and Technical Supervision Bureau, and shall be carried out together with the vessels.
Technical requirements for standard parts adopted in this standard. It shall comply with the provisions in the corresponding standards. The technical conditions for stainless steel manholes and handholes manufactured and supplied by designated manufacturers are discussed. 4.0.2 Flanges and flange covers
The raw shrimp steel plates used to manufacture flanges and flange covers shall comply with the provisions of GB3274 "Hot-rolled thick steel plates and strips of carbon structural steel and low-alloy structural steel" and GB6654 "Carbon steel and low-alloy steel thick steel plates for pressure vessels". Forgings shall comply with the II grade acceptance of JB4726 "Carbon steel and low-alloy steel forgings for pressure vessels". The dimensional processing accuracy is stipulated as follows:
The dimensional tolerances of flanges and flange covers shall comply with the standards of HG20603 "Technical Conditions for Steel Pipe Flanges (European System)".
Surface roughness of sealing surface:
Non-metallic soft gasket Ra=12.5μm;
Flexible graphite composite gasket Ra-6.3um
Metal spiral wound gasket Ra-6.3um.
The 16Mn steel (rolled or forged) of the long-neck butt-weld flange should be normalized and tempered.
Slip-on flanges are allowed to be spliced ​​with plates or bars. The spliced ​​welds are required to be fully penetrated. The welds must be 100% radiographically inspected. The radiographic inspection is carried out in accordance with JB4730, and the inspection results are qualified at level 1 (if there are special requirements, they should be indicated on the drawings). The spliced ​​flanges should be subjected to 12
post-weld stress relief heat treatment. For flanges with ring linings, the inspection holes should be passed through 0.4-0.5MPa compressed air to check the weld quality. All flange sealing surfaces are processed after the ventilation inspection is qualified.
The sealing surface of the flange shall not have cracks or other defects that reduce strength and sealing reliability.
4.0.3 Cylinder Section
The materials used to manufacture the cylinder section shall comply with the provisions of GB4237 and GB/T14976, and be consistent with the materials of the container in which it is located. The allowable deviation of the outer circumference of the rolled section is ±3mm, and the structural type of the weld is as noted in the drawing. 4.0.4 Fasteners
Normal pressure manholes and manholes with a nominal pressure of 0.6MPa are connected by bolts and nuts, and manholes with a nominal pressure of 1.0MPa and above are connected by studs and nuts.
4.0.5 Gaskets
Non-metallic soft gaskets are used for stainless steel manholes with a nominal pressure of 1.6MPa and below; metal spiral wound gaskets are used for stainless steel manholes with a nominal pressure of 2.5MPa and 4.0MPa, and flexible graphite composite gaskets are used for handholes with a nominal pressure of 2.5MPa and 4.0MPa: rubber gaskets are used for normal pressure manholes and normal pressure quick-opening handholes. Rubber sheet gaskets should be made of a whole sheet, and no splicing is allowed. The edges of the gaskets should be cut neatly, and the sealing surface of the gasket should be flat after assembly without warping or deformation. The rubber is a medium hardness smooth rubber sheet with the code number 4710 in GB5574.
4.0.6 Pickling, passivation treatment and pressure test shall be carried out in accordance with the requirements of the container assembly drawing and shall be carried out together with the container.
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