HG/T 21557.1-1995 Carbon steel step ring packing HG/T21557.1-1995 Standard download decompression password: www.bzxz.net

Carbon steel step ring packing
HG/T 21557.195
1 Subject content and scope of application
1.0.1 This standard specifies the material, specifications, manufacturing requirements, inspection rules and packaging, storage and transportation requirements of carbon steel step ring packing with diameters of 25, 38, 50 and 76 mm. 1.0.2 The applicable temperature range of carbon steel step ring packing is less than or equal to 350℃. 117
GB1184
GB1804
Referenced standards
《High-quality carbon structural steel thin steel plates and strips》《Provisions for shape and position tolerances without tolerances》《Tolerances and fits without tolerances for limit deviations》《Dimensions, shape, weight and allowable deviations of cold-rolled steel plates and strips》3 Marking, specifications and characteristics
- XX -CRCS- XX
Nominal diameter
Carbon steel step ring
Standard number
3.2 Specifications and characteristics
3.2.1 The appearance of the carbon steel step ring is a cylinder with several windows on the surface, with a height-to-diameter ratio of 1:2, and a trumpet-shaped expansion port is added at one end of the cylinder, as shown in Figure 3.2.1, D2
Figure 3.2.1 Carbon steel step ring
In the figure: the size unit is mm: D, a
-diameter; Da—
-bell mouth diameter H——height,—wall thickness. 3.2.2 Diameter series: The nominal diameters of step rings commonly used in industry are DN25, DN38, DN50, and DN76mm.
3.2.3 The specifications and dimensions of carbon steel step ring packing are shown in Table 3.2.3. Table 3.2.3
Specifications and dimensions of carbon steel step ring packing
Bell diameter
42.5±0.5
12.5±0.2
Characteristic parameters of carbon steel step ring packing are shown in Table 3.2.4. Table 3.2.4
Diameter×height×wall thickness
Nominal diameter
76×38×1.5
50X25×1.0
38X19×0.8
25X12.5X0.6
0.6±0.06
0.8±0.07
1.0±0.09
1.2±0.12
Carbon steel step Characteristic parameters of ladder ring packing
Stacking number
Stacking density
(kg/m)
Specific surface area
(m*/m2)
Ovality deviation
Not more than
Porosity
(m*/m)
Dry packing factor
4.0.1 Carbon steel ladder ring material shall comply with the technical requirements of cold-rolled steel plate in GB710 standard. 4.0.2 The size, shape, weight and allowable deviation of cold-rolled steel plate and steel strip shall comply with the B-level precision in GB708 standard.
4.0.3 The selected materials should have quality inspection certificates and certificates, and should be sampled and inspected regularly. 121
Manufacturing requirementsbZxz.net
The structural dimensions of carbon steel step ring packing are shown in Figure 5.0.1 and Table 5.0.1.5. 0. 1
Figure 5.0.1 Structural dimensions of carbon steel step rings
In the figure: the dimensions are in mm; H,
-bell height; H2—
-window width, H width, H—
-height:
Dr—diameter; Da—
-bell diameter; H——plate width before processing, L-plate length before processing A
-distance from the edge of the window hole to the end of the plate: B—
radius: -
-wall thickness.
38±0.57.516.58.539.2
DN2512.5±0.22.5
Window length C→
One window hole spacing;RR
Carbon steel step ring packing series size
19.642.5±0.5
3.02351.5
5.0.2The packing processing accuracy shall be in accordance with the IT13 grade in GB1804 standard and the B grade accuracy in GB1184 standard.
5.0.3There shall be no cracks or rust marks on the surface of the packing. There shall be no burrs around the packing. 5.0.4The upper and lower edges of the packing ring joints are not allowed to be misaligned. The gap of the packing joints of DN25 and DN38mm shall be less than 0.4mm; the gap of the packing joints of DN50 and DN76mm shall be less than 0.8mm. The conical flange joint of the packing ring is allowed to have a gap. 123
Inspection and acceptance
6.1 Acceptance rules
6.1.1 The packing should be accepted in batches, and packing of one size can be regarded as a batch. The batches of various types of packing are shown in Table 6.1.1. When the production volume of packing of one size is less than the batch value specified in Table 6.1, 1, the production volume of packing of one size can be regarded as a batch.
Table 6.1.1 Packing batches
Nominal diameter DN (mm)
Less than 38
Batch (m2)
6.1.2 The sampling quantity for testing in each batch of packing shall not be less than 60. 6.1.3 If more than 5% of the sample size does not meet the requirements of this standard, the sampling quantity should be doubled from the same batch of products and retested. The results of the repeated test also apply to the batch of products. If the unqualified rate of the retested samples is still greater than 5% of the sampling volume, the batch of products is unqualified. 6.2 Inspection method
6.2.1 The diameter, wall thickness and height of the packing are measured with a vernier caliper. Each test item of each sample shall not be less than 2 test points. The measurement value requirements are shown in Table 3.2.3. 6.2.2 The ovality is measured with a vernier caliper. The ovality is determined by measuring the difference between two mutually perpendicular diameters. The measurement requirements are shown in Table 3.2.3.
6.2.3 When the shape and size of the packing are changed, the packing characteristics, fluid mechanics and mass transfer performance tests shall be carried out. 124
Marking, packaging and storage and transportation
7.1 Marking
7.1.1 There should be a certificate of conformity in the product packaging box. The certificate of conformity should indicate the product name, specification and size, inspection results, inspection date, production date, manufacturer name, and be stamped with the quality inspection seal and inspector seal. 7.1.2 The outside of the packaging box should be marked with the product name, specification, packing quality (or quantity), manufacturer, and moisture-proof, anti-pressure and other marks.
7.2 Packaging
The packaging should be made of dry boxes or other packaging materials, lined with moisture-proof materials. The packaging box must be strong enough to ensure that it is not damaged during transportation and loading and unloading. 7.3 Transportation and storage
7.3.1 The product must be protected from moisture and rain during transportation. 7.3.2 The product should be stored in a dry, non-corrosive place, and ensure that the inner packaging is not damaged. 125
Additional Notes
Proposing unit, chief editor unit
and main drafters of this standard
Proposing unit: 1
Chemical Engineering Design Technology Center Station, Ministry of Chemical Industry Chief editor unit: Chemical Engineering Design Technology Center Station, Ministry of Chemical Industry Chief editor: Yu Hongshou Lin Jie
Reviewer: Xiao Chengji Tan Chong Fei Weiyang
Li Chunfang
Approving person: Wang Fuhua　
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