HG 21535-1995 Quick-opening hand hole for swing cover.

HG 21535-1995 Swing cover quick opening hand hole. Attached picture HG21535-1995 standard download decompression password: www.bzxz.net

Quick-opening handholes for revolving covers
HG 21535---95
Subject content and scope of application
This standard specifies the type, basic parameters, dimensions, technical requirements and relevant use regulations of quick-opening handholes for revolving covers made of carbon steel.
This standard applies to quick-opening handholes for revolving covers with a nominal pressure PN less than or equal to 0.6MPa and a working temperature limited to the range specified in Table 3-2.
Note: When using oil-resistant asbestos rubber sheet gaskets, the upper limit of the working temperature is 150℃. 187
GB 97.185
GB880-86
GB91-86
HG21514-95
(Flat washer - Grade A)
"Pin with hole"
"Split pin"
Reference standard
"Types and technical conditions of manholes and handholes made of carbon steel and low alloy steel" 3 Types, basic parameters and dimensions
The types, basic parameters and dimensions of handholes are shown in the figure below and the provisions of Table 3-1 to Table 3-3.AA
Nominal pressure
Standard number
GB 880-86
GB 97.1-85
GB 91-86
Gasket 8=3
Hexagonal nut
Joint bolt
Upper ear plate
Lower re-plate
Maximum non-impact working pressure at working temperature
Maximum non-impact working pressure
Note: The maximum non-impact working pressure at intermediate temperature can be determined by the internal seeding method according to the pressure value of this table. Ruler
Sealing surface
(FS type)
Rod groove surface
(TG type)
Nominal nominal
Q235-A
Asbestos rubber sheet
Oil-resistant asbestos rubber sheet
Q235-A
Q235-A
|Q235—A
Q235—A
Low carbon steel
Q235-A·F
Hexagon
[270|230|205,210|140|125
159×61
[396|350|320320|205|145
270|230|205|210|1401
Bolt nut
1396350|320/320|2051
Table 3-3
Swing bolt
Diameter×length
M20X100
M24X120
M20×100||tt ||M24X120
Total mass
Note: The hand hole height HI is determined based on the diameter of the container being not less than twice the nominal diameter of the hand hole; if there are special requirements, changes are allowed, but the changed H dimension must be indicated and the total mass of the hand hole must be corrected. 190
Technical requirements
The technical requirements for hand holes shall comply with the provisions of Chapter 4 "Technical Conditions" in HG21514. 191wwW.bzxz.Net
Marking example
Nominal pressure PNO.6. Nominal diameter DN250H, =145.FS type sealing surface, quick-opening hand hole of the intermediate cover with asbestos rubber sheet gasket, the specified marking symbol is: Hand hole FS (A·G) 250-0.6HG21535-95H: -160 (non-standard size) upper For example, the prescribed marking symbol for a manhole is: Hand hole FS (A·G) 250-0.6H=160HG21535-95192
Month Proposing unit, chief editing unit
Additional notes
and main drafters
Proposing unit: Equipment Design Technology Center Station, Ministry of Chemical Industry Chief editing unit: China Tianchen Chemical Engineering Corporation Main drafters: Li Wenren, Zhao Cheng and Shen Pengfei193
Manhole and handhole made of carbon steel and low alloy steel HG2151421535--95
Preparation instructions
The three standards "Manholes and Handholes made of Carbon Steel and Low Alloy Steel" (hereinafter referred to as JB-79 standards) promulgated and implemented by the First Ministry of Machine Building, the Ministry of Petroleum and the Ministry of Chemical Industry in 1979 have been in use for more than ten years. Since most of the standards and specifications followed by this standard have been updated, especially the standard pipe flanges, flange covers, fasteners and gaskets used in the standard of manholes and handholes, the Ministry of Chemical Industry has issued the new standard HGJ44-76-91 "Steel pipe flanges, gaskets, fasteners" (hereinafter referred to as HGI pipe flanges), which has undergone many changes in type, parameters, size, materials, etc. The JB-79 manhole and handhole materials are not in compliance with the scope of use specified in the current GB15089 "Steel Container" standard. On the other hand, through the practice of the JB-79 manhole and handhole standard for many years and the development of its technology, the JB-79 standard also needs to be further improved and improved in terms of structure, type, specification, size, etc. Therefore, the Ministry of Chemical Industry has arranged for our company to formulate the HG "Carbon Steel, Low Alloy Steel Manhole and Handhole" standard. Our company has formulated this standard on the basis of the B-79 manhole and handhole standard after widely soliciting opinions from the design, manufacturing and use departments. -—, Comparison between this standard and "JB-79" standard 1. Changes in types
According to the needs of use, this standard divides manholes and handholes into two categories: quick-opening and non-quick-opening manholes and handholes. According to the nominal pressure, manholes and handholes are divided into normal pressure and extraordinary pressure. For extraordinary pressure manholes and handholes that are not quick to open, the main pressure-bearing parts such as flange covers, flanges, bolts (columns), nuts, gaskets, etc. all adopt the HGJ pipe flange standard. The HGI pipe flange standard is suitable for the "metric piping size series, which is in line with the current national conditions that domestic seamless pipes (for hand holes) are still mainly metric specifications. The "neck-welded flange" in the HGI pipe flange will be used as a common pipe flange type in engineering design in the future. For this reason, this standard has added rotating covers, vertical hanging covers, and horizontal hanging covers with neck-welded flange manholes.
The rotating quick-opening manhole and handhole adopt the new structure of West German DIN28125-89 standard this time. The circular manhole adopts an arch cover structure: the handhole adopts a square flat cover structure: the oblong manhole is modified to an elliptical manhole structure. This structure highlights the advantages of light weight, compact and reasonable structure, and is undoubtedly an advanced structure in use. However, this structure is relatively It is complex, troublesome to process, and has a high production cost per piece. It may also bring difficulties in supply, so it is more suitable for fixed-point production and supply. 2. Changes in nominal pressure, nominal true diameter and sealing surface type (1) Very high pressure that is not opened quickly, hand hole
(a) According to the range specified by HGI pipe flanges, for plate-type flat-weld flanges and hand holes, this standard only has one type of raised face flange sealing surface. Also, due to the restrictions of HGJ pipe flanges, the upper limit of the nominal diameter of neck-welded flanges and hand holes with a nominal pressure of PN=6.3MPa is DN400mm.
(b) Plate-type flat-weld flanges and hand holes have a nominal pressure of PNO.6MPa. This is because this type of 1 is limited in HGJ pipe flanges. 95
type flanges are used in chemical process piping systems. Therefore, the scope of its application is narrowed accordingly in this standard, and the use of necked flat welding flange manholes and handholes is expanded as much as possible. (c) The three types of manholes and handholes determined by this standard, namely plate flat welding flanges, necked flat welding flanges and necked butt welding flanges, are connected to each other in the nominal pressure series but do not overlap. This not only meets the needs but also simplifies the specifications. The lower limit nominal diameter of all manholes is DN400mm, which fully meets the needs of some small diameter tower containers, etc. (2) Quick-opening extraordinary pressure manholes
(a) The nominal size of the elliptical rotary cover quick-opening manhole is set at 450×350. This is based on the DIN28125 standard which only specifies This specification is set, and the opinions collected also hope to enlarge the size, because the 400×300 manhole in the JB-79 standard is too small, which is really inconvenient for people to enter and exit.
(b) Cancel the long round rotary cover quick-opening manhole 10kgf/cm2 pressure and the intermediate arch cover quick-opening manhole Pg16kgf/cm2 series in the JB-79 standard. The reason is that the quick-opening manhole is frequently opened and closed during operation, so the manhole cover is required to be as light as possible. According to the investigation, some widely used manholes are not very satisfied with the JB-79 manhole. The maximum working pressure of this manhole is 8bar in the DIN28125 standard. For this reason, this standard only stipulates PNO.6MPa-pressure level. Manholes with high pressure and heavy weight are no longer included. In this way, if the use requirements can be basically met in most occasions, the new standard can be more practical, and the use of manholes with quick-opening structure under lower pressure will be safer and more reliable.
(3) A comprehensive comparison of this standard with JB-79 and the handhole standard in terms of name, nominal pressure, nominal diameter, and sealing surface type is shown in Table 1 (only the changed parts are listed). 196
aura/ay
6 -589 H
.(00%)
196-81912 0
62629 r
62--989 ar
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