HG/T 21557.2-1995 Stainless steel step ring packing HG/T21557.2-1995 Standard download decompression password: www.bzxz.net

Stainless steel step ring packing
HG/T 21557.2-95
Additional instructions
Month This standard proposes the unit, editor-in-chief
and the main drafter
Proposing unit: Chemical Engineering Design Technology Center Station of the Ministry of Chemical Industry Editor-in-chief: Chemical Engineering Design Technology Center Station of the Ministry of Chemical Industry Editor-in-chief: Yu Hongshou Lin Jie
Reviewer: Xiao Chengji Tan Chong Fei Weiyang Li Chunfang Reviewer:
Wang Fuhua
Subject content and applicable scope Kang
1.0.1 This standard specifies the material, specification, manufacturing requirements, inspection rules and packaging, storage and transportation requirements of stainless steel step ring packing with diameters of 25, 38, 50 and 76 mm. 1.0.2 The applicable temperature range of stainless steel step ring packing is less than 400℃. 129
GB3280
GB 1184
GB 1804
Cited standards
《Cold-rolled stainless steel plates
Provisions for shape and position tolerances without tolerances》Tolerances and fits-Limit deviations of dimensions without tolerances》《Dimensions, shape, weight and allowable deviations of cold-rolled steel plates and strips》3 Marking, specifications and characteristics
XXX. X-XX-CRSS-Xx
Nominal diameter
Stainless steel step ring
Standard number
3.2 Specifications and characteristics
3.2.1 The stainless step ring has a cylindrical shape with a number of windows on the surface. Its height-to-diameter ratio is 1*2, and a trumpet-shaped expansion port is added at one end of the cylinder, as shown in Figure 3.2.1. Figure 3.2.1 Stainless steel step rings The dimensions in the figure are in mm (D, - diameter D - port diameter H - height - wall height). 3.2.2 Diameter series: The nominal diameters of step rings commonly used in industry are DN25, DN38, DN50 and DN76 mm. 3.2.3 The specifications and dimensions of stainless steel step ring packing are shown in Table 3.2.3. Table 3.2.3
Specifications and dimensions of stainless steel step ring packing
Bell mouth diameter
42.5±0.5
12.5±0.2
0.5±0.05
0.6±0.07
0.8±0.07
1.2±0.10
The geometric characteristic parameters of stainless steel step ring packing are shown in Table 3.2.4. Table 3.2. 4
Diameter×Height
Nominal diameterwwW.bzxz.Net
DiXHX8
76X38×1.2
50×25×0.8
38×19×0.6
25X12.5X0.5
Characteristics of stainless steel step ring packing
Stacking number
Stacking density
(kg/m2)
Specific surface area
(m\/m*)
Porosity
Roundness deviation
Not more than
Dry packing factor
(m*/m2)
4 Materials
4.0.1 The selection of stainless steel materials shall be in accordance with the technical requirements specified in GB3280. 4.0.2 The size, shape, weight and allowable deviation of the stainless steel plates and strips shall be in accordance with the B-level accuracy in GB708 standard.
4.03 The selected materials shall have quality inspection certificates and certificates of conformity, and shall be sampled and inspected regularly. 133
S Manufacturing requirements
5.0.1 The structural dimensions of stainless steel step ring packing are shown in Figure 5.0.1 and Table 5.0.1. D
Figure 5.0.1 Stainless steel step ring structure dimensions
In the figure, the dimensions are in mm, H is the height of the bell mouth, H is the width from the mouth, Ha is the width in square meters, H is the height
D, is the diameter, Dr is the diameter of the mouth, H, is the
plate width before processing L-
A is the distance from the edge of the window hole to the mouth of the plate, B is the radius, the wall thickness,
plate length before processing
window length C is the distance between the window holes RR is the curvature
change 5. 0. 1
stainless steel step ring packing series dimensions
DN2512.5±0.2
16.58.539.2
250
17. 55. 5
5.0.2 The packing processing accuracy shall be in accordance with the IT13 grade in GB1804 standard and the B grade in GB1184 standard.
5.0.3 There shall be no cracks or rust marks on the surface of the packing. There shall be no burrs around the packing. 5.0.4 The joints of the packing rings shall not be allowed to be misaligned. The gap between the joints of the packings of DN25 and DN38mm shall be less than 0.4mm; the gap between the joints of the packings of DN50 and DN76mm shall be less than 0.8mm. The conical flange joints of the packing rings are allowed to have gaps.
Inspection and Acceptance
Acceptance Rules
6.1.1 The packings shall be accepted in batches, and packings of one size can be regarded as one batch. The batches of various types of packings are shown in Table 6.1.1. When the production volume of packings of one size is less than the batch specified in Table 6.1.1, the production volume of packings of one size can be regarded as one batch.
Table 6.1. Filling in batches
Nominal diameter DN (mm)
Less than 38
6.1.2 The number of samples for testing in each batch of fillers shall not be less than 60. 3
6.1.3 If more than 5% of the number of samples do not meet the requirements of this standard, the number of samples should be doubled from the same batch of products and retested. The results of the repeated tests are applicable to the batch of products. If the unqualified rate of the retested samples is still greater than 5% of the number of samples, the batch of products is unqualified. 6.2 Inspection method
6.2.1 The diameter, wall thickness and height of the filler 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 conducted. 136
Marking, packaging and storage and transportation
7.1 Marking
7.1.1 The product packaging box shall contain a certificate of conformity, which shall indicate the product name, specifications and dimensions, inspection results, inspection date, production date, manufacturer's name, and shall be stamped with the quality inspection seal and inspector seal. 7.1.2 The packaging box shall indicate the product name, specifications, packing quality (or quantity), manufacturer, and moisture-proof and heavy pressure-proof marks.
7.2 Packaging
The packaging shall be made of dry boxes or other packaging materials, lined with moisture-proof materials. 7. 2. 1
The packaging box must be strong enough to ensure that it is not damaged during handling and loading and unloading. 7.2.2
7.3 Transportation and Storage
7.3.1 Products should be protected from moisture and corrosion during transportation. 7.3.2 Products should be stored in a dry, non-corrosive place and ensure that the inner packaging is not damaged. 137
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