This standard specifies the characteristics, lining methods, surface conditions and minimum thickness of cement mortar for centrifugal lining of ductile iron pipes for pressure and non-pressure pipelines as defined in GB/T 13295 and Appendix A. GB/T 17457-1998 General requirements for centrifugal lining of ductile iron pipes with cement mortar GB/T17457-1998 Standard download decompression password: www.bzxz.net
This standard specifies the characteristics, lining methods, surface conditions and minimum thickness of cement mortar for centrifugal lining of ductile iron pipes for pressure and non-pressure pipelines as defined in GB/T 13295 and Appendix A.

GB/T174571998
This standard adopts the requirements of IS4179:1985 Cement mortar centrifugal lining for ductile iron pipes for pressure and non-pressure pipelines. The differences between this standard and IS4179 are: the reference standards are added, the description of the distribution law of particles in the lining is added in Chapter 5, so that the requirements for the layer are more specific: Appendix A is added to clarify the definition of ductile iron pipes in IS2531:1991 and IS07186:1996. Appendix A of this standard is the appendix of the standard. This standard is proposed by the State Bureau of Machinery Industry. This standard is under the jurisdiction of the National Technical Committee for Standardization of Metallic and Non-metallic Coverings. The responsible drafting units are: Wuhan Materials Protection Research Institute, Xuzhou Everbright Xinxing Casting Pipe Co., Ltd. The main drafters of this standard are Gao Zhi, Qian Hongji, Huang Guangjing, Feng Changzhi, and Xiao Dejun. GB/T17457-1998
ISO Foreword
ISO (International Organization for Standardization) is a global federation of national standard bodies (ISO member bodies). The work of formulating international standards is generally carried out through ISO technical committees. Each member body interested in the relevant topics determined by the technical committee has the right to make representations to the committee. Governments and international organizations that have ties to ISO may also participate in this work. The draft international standard adopted by the technical committee is first sent to the member bodies for approval before it is approved as an international standard by the ISO Council. According to ISO procedures, it can only be approved after at least 75% of the member bodies vote in favor. This international standard ISO4179 was formulated by ISO/TC5 Technical Committee on Ferrous Metals and Metal Pipe Fittings. ISO 4179 was first published in 1980. This second edition cancels and replaces the first edition, and contains the following technical amendments: Article 1: Adding relevant ISO 7186 and -1 interpretation; Article 2: Adding ISO 6708 and IS718G; Article 1: Modifying the value of 50% in the second paragraph; Article 8: Modifying the paragraph!
Table: Adding data corresponding to each column of group V of DN, 1 Scope
National Standard of the People's Republic of China
Ductile iron pipes -Centrilugal renment mortarHaing - General requiremenisGB/T 174571998
eqv is0 4179: 1985
This standard specifies the physical properties of the centrifugal lining cement slurry of ductile iron pipes for small non-compressive pipelines (defined in B/T13295 and Appendix A), the lining method, the surface condition and the minimum drop. Note: If it is used to transport highly corrosive liquids, the following methods are allowed to be used alone or in combination: Increase the thickness of the lining:
-Change the water source label;
Apply it on the surface,
2 Reference standards
The texts contained in the following standards constitute the provisions of this standard through their use in this document. The versions indicated are valid at the time of edition of this standard. All standards are subject to revision: Parties using this standard should explore the possibility of using the latest versions of the following standards. GB/1175-12 Portland cement, ordinary silicate cement (il3/T13295-1991 Centrifugal cast iron pipe (ne1S0) 2531: 1986) GB/T 1164-11993 Sand for construction
G13/T 17458-1998
Ductile iron pipe
3 Materials
3.1 Water yoke
The cement used for sealing layer shall comply with G13/T 171.
Test composition of fresh mortar for lining layer by centrifugal method (CIS) 66(: The grade of water-sand mortar can be determined by the manufacturer: the user should be informed that 3.2 The sand used should have a controlled particle size distribution from fine to fine; it should be clean and produce fine particles that are smooth, hard, firm and stable.
Sampling should be carried out in accordance with GB/T14684.
The screening results should be obtained in accordance with (B/T11684, and the sand particle size curve should be drawn based on this result, and it should meet the following requirements: The mass fraction of fine sand (seconds of sand passing through a sieve with a size of 0.125mm) should not exceed 10% . The mass fraction of sand particles with the lightest weight equal to one-third of the nominal thickness of the cement mortar lining shall not be less than 10%. The mass fraction of the coarsest sand (the sand particles that cannot pass through the sieve hole closest to one-half of the nominal thickness of the cement mortar lining) shall not be less than 5%. The cleanliness of the sand on the cement mortar shall be inspected according to the following methods: Approved by the State Administration of Quality and Technical Supervision on August 12, 1998, and implemented on July 1, 1999. GB/T17457--1998. The quality of the cement mortar shall be inspected by colorimetry according to GB/T14681 (using this method, the sand shall not produce any color change deeper than the standard color). The content of cement and other fine particles (with a size of 60~80um) in the cement mortar shall be tested according to the requirements for superior products in GB/T14684. The mass fraction of organic impurities and cement in the sand should not be greater than 2%. 3.3 Water
The water used for preparing mortar should not contain any substance that is harmful to the mortar or to the water to be transported in the pipeline. Solid mineral particles that can always meet this requirement may be allowed to exist in the prepared water. 3.4 Mortar
The mortar for the lining should be made of cement, sand and water. Only additives that are not harmful to the quality of the lining and the quality of the water to be transported and meet all the requirements of this national standard for the lining should be used. The mortar should be fully mixed and stable so that the lining is dense and well connected. The mortar should be composed of at least 1 part of cement and 3.5 parts of sand (i.e., the mass ratio S/C is 3.5). 4 Requirements for the surface of the lining substrate
All foreign matter, loose iron or any other material that may interfere with the good bonding between the lining and the lining should be removed from the surface of the lining.
The inner surface of the pipe should not have any metal protrusions whose height may exceed 50 mm of the lining thickness. 5 Lining
Mortar is poured on the inner wall of the pipe by centrifugal method to form a "lining". In addition to coating the inner surface of the pipe body with mortar, the other parts of the pipeline in contact with the conveying water should also be covered with mortar. The mortar should not have any holes or obvious bubbles. At the same time, the density of each part of the lining should be maximized. The consistency of the mortar, the rotation speed of the pipe during the centrifugation process and the centrifugation time should be properly controlled to minimize the segregation of sand in the lining and distribute the sand particles in a coarse to fine pattern from the pipe wall to the surface.bzxZ.net
After the centrifugation, the lining should be cured at a temperature below 0°C. The moisture of the mortar should be evaporated as slowly as possible to avoid poor hardening. Damaged or defective areas can be repaired, but the damaged mortar should be removed from the area first, and then fresh mortar should be applied with a tool such as a repair knife to repair the defective parts and regain a continuous lining with a constant thickness. The repair mortar should be prepared according to the schedule; if necessary, additives can be added to ensure good adhesion to the undamaged area. 6 Thickness of the lining layer
The nominal thickness of the lining layer and the average value of the minimum thickness allowed as well as the local minimum thickness allowed are shown in Figure 1 and Table 1. The lining layer at the pipe end can be lower than the minimum thickness value. The length of the trimmed edge of the raw pipe end should be as small as possible, and in any case its length should not exceed F50mm.
7 Measurement of lining thickness
The lining thickness can be measured by the force method of inserting a steel needle into the mortar just centrifuged, or by the non-destructive measurement method of the hardened mortar.
The lining thickness measurement should be carried out at both ends of the pipe, and each end should be measured on at least one cross section perpendicular to the axis. Each section should be at least 200mm from the pipe end, and four points 90 degrees apart should be taken for measurement. The measured value of the sealing layer thickness should be accurate to 0.1mm. 1) The method for determining the ratio of cement to cement S/ can refer to GB/T 17458 Ductile iron cement slurry centrifugal method for the analysis of freshly mixed cement mortar layers
2 This standard is also applicable to the treatment of cement mortar layers by centrifugal method. CB/T 17457 1998
The thickness of any point measured on the pipe shall not be less than the minimum value given in Table 1. The arithmetic mean of the four points measured on each cross section shall not be less than the minimum mean value specified in Table 1. 8 Surface condition of hardened lining
The surface of the cement mortar lining shall be smooth and individual isolated sand particles shall not be too obvious on the lining surface. The lining shall be free of scattering and shall not be free of grooves or ripples that may reduce the local thickness of the lining to less than the minimum value specified in Table 1.
Cracks formed due to the shrinkage of the lining are inevitable. The allowable width of such cracks and isolated cracks that may be caused by production or transportation is not greater than 0.8 mm.The structure of the lining is related to the centrifugal process. A thin layer of fine sand and cement is formed on the surface of the lining, which extends to about one quarter of the total thickness of the mortar. 9.2 Thickness of the lining
The various tests specified in this standard shall be carried out under the following conditions. 9.2.1 The following conditions shall apply: 9.2.2 The following conditions shall apply: 9.2.3 The following conditions shall apply: 9.2.4 The following conditions shall apply: 9.2.5 The following conditions shall apply: 9.2.6 The following conditions shall apply: 9.2.7 The following conditions shall apply: 9.2.8 The following conditions shall apply: 9.2.9 The following conditions shall apply: 1. The following conditions shall apply: 1. The following conditions shall apply: 1. The following conditions shall apply: 1. The following conditions shall apply: 2. The following conditions shall apply: 3. The following conditions shall apply: 4. The following conditions shall apply: 5. The following conditions shall apply: 6. The following conditions shall apply: 7. The following conditions shall apply: 8. The following conditions shall apply: 9.2.1 The following conditions shall apply: 1. The following conditions shall apply: 1. The following conditions shall apply: 1. The following conditions shall apply: 2. The following conditions shall apply: 3. The following conditions shall apply: 4. The following conditions shall apply: 5 ...6. The following conditions shall apply: 7. The following conditions shall apply: 8. The following conditions shall apply: 1. The following conditions shall apply: 1. The following conditions shall apply: 1. The following conditions shall apply: 1. The following conditions shall apply: 1. The following conditions shall apply: 1. The following conditions shall apply: 2. The following conditions shall apply: 1 9.3 Appearance of the lining
The appearance of the lining of each pipe shall be checked, with particular attention to the surface condition of the lining and the repair condition of the end seal. Any repair deemed necessary after this inspection shall be carried out in accordance with the methods specified in Chapter 5. Figure 1 Schematic diagram of spherical cast iron pipe and the corresponding DN group with the codes in Table 1
Nominal size\
1) This table is equivalent to the corresponding table GB/T17457-1998 in accordance with IS06708
Table 1 Cement mortar lining
Lining thickness:
Nominal
Average value
Minimum value
2) This thickness is calculated based on the nominal thickness and the inner diameter of the nominal size below, and the wear rate is 2 200kg/m*3) According to the existing technical literature, it is believed that the minimum value of the rear part is 1-u, which is sufficient to ensure the pipe is pain-proof. mt
per unit length
approximate mass "
A1 Ductile iron pipe for pressure piping
CB/T174571998
(Appendix to the standard)
Ductile iron pipe for pressure piping and non-pressure piping A1.1 This Appendix A1 is equivalent to 1S0 2531:1991 corresponding part. 41.2 Manufacturing process of cast iron pipes Ductile iron pipes are manufactured by one of the following four processes: 1) Centrifugal casting of metal molds using production lines or non-production lines; 2) Centrifugal casting of sand molds; 3) Sand mold casting: 1) Metal mold casting. A1.3 Nominal size The nominal size shall be implemented in accordance with the provisions of 1S0) 6708 (see Table 1). A1.4 Maximum working force and pressure test The actual test pressure shall not exceed the following values: -JN 40-I>N 300/p=10 MPat-1)N 350~-DN 600.p=8 MPa-2)N 350~-DN 600.p=8 MPa-3)N 700~DN 1000:^-6 MPa:-DN 12U0~DN 2000: =4 MPat
- -1IN 2200-~DN 2600: p--2. 5 MFa.A2 Ductile iron pipe for non-pressure pipeline
A2.1 This Appendix A2 is equivalent to the corresponding part of [SC) 7186: 1996, A2.2 Specification
This standard is the meaning of ductile iron pipe refers to the ductile iron pipe used for conveying sewage in the state or under low pressure: F0,6 MPa.
If a higher working pressure is required, the supplier and the consignee shall agree on the wall thickness of the pipe separately.
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