Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is developed in accordance with the rules given in GB/T 1.1-2009 Directives for standardization - Part 1: Structure and drafting of standards.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.
This standard replaces DL/T 742-2001 Technical specification for plastic parts of cooling tower. In addition to editorial changes, the following main technical changes have been made with respect to DL/T 742-2001:
——Contents relevant to design, operation and test in the original standard that are repeated in other professional standards are deleted;
——The product quality standard for the packing bracket is added;
——Contents of product quality inspection, acceptance, quality standard, packaging, marking, storage and transportation are added.
This standard was proposed by the China Electricity Council.
This standard is under the jurisdiction of the Technical Committee on Power Station Steam Turbine of Standardization Administration of Power Industry (DL/TC 07).
This standard replaces DL/T 742-2001 Technical specification for plastic parts of cooling tower from the implementation date hereof.
This standard was firstly issued in 2001, and this is the first revision.
During the process of implementing this standard, the relevant comments and recommendations, whenever necessary, can be fed back to the Standardization Center of the China Electricity Council (No.1, 2nd Lane, Baiguang Road, Beijing, 100761, China).
Quality standard of plastic parts for wet cooling tower
1 Scope
This standard specifies basic requirements for the manufacture, quality inspection, packaging, storage and transportation of plastic parts of wet cooling tower.
It is applicable to plastic parts such as film packing, distribution pipe and eliminator made of PVC plastics, spray device made of engineering plastics, and packing bracket made of fiber-reinforced plastics (glass fiber reinforced plastics).
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 1033.1 Plastics - Methods for determining the density of non-cellular plastics - Part 1: Immersion method, liquid pyknometer method and titration method
GB/T 1040.1 Plastics - Determination of tensile properties - Part 1: General principles
GB/T 1040.3 Plastics - Determination of tensile properties - Part 3: Test conditions for films and sheets
GB/T 1446 Fiber-reinforced plastics composites - The generals for determination of properties
GB/T 1447 Fiber-reinforced plastics composites - Determination of tensile properties
GB/T 1449 Fibre-reinforced plastic composites - Determination of flexural properties
GB/T 1633 Plastics - Thermoplastic materials - Determination of Vicat softening temperature (VST)
GB/T 1843 Plastics - Determination of izod impact strength
GB/T 2406.1 Plastics - Determination of burning behaviour by oxygen index - Part 1: Guidance
GB/T 2406.2 Plastics - Determination of burning behaviour by oxygen index - Part 2: Ambient-temperature test
GB/T 2828.1 Sampling procedures for inspection by attributes - Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection
GB/T 3854 Test method for hardness of reinforced plastics by means of a Barcol impresser
GB/T 4219.1 Unplasticized poly (vinyl chloride) (PVC-U) piping system for industrial applications - Part 1: Pipes
GB/T 6671 Thermoplastics pipes - Determination of longitudinal reversion
GB/T 8802 Thermoplastics pipes and fitting - Determination of vicat softening temperature
GB/T 8804.1 Thermoplastic pipes - Determination of tensile properties - Party 1: General test method
GB/T 8804.2 Thermoplastic pipes - Determination of tensile properties - Part 2: Pipes made of unplasticized poly (vinyl chloride) (PVC-U), chlorinated poly (vinyl chloride) (PVC-C) and high-impact poly (vinyl chloride)(PVC-HI)
GB/T 8806 Plastics piping systems - Plastics components - Determination of dimensions
QB/T 1130 Test method for right angle tearing property of plastics
QB/T 2803 Determination of deflection for rigid plastic pipes
DL/T 933 Test methods for determining the performance of cooling tower of transfer packing, drift eliminator and sprayer
3 Terms and definitions
For the purpose of this standard, the following terms and definitions apply.
3.1
poly vinyl chloride plastics; PVC
material produced by extrusion of PVC resin and various additives
3.2
service life
service term of the plastic parts of cooling tower to meet their technical and economical requirements under normal service conditions
3.3
flat packing chip
flat and smooth plastic sheet adopted for the hotforming of plastic packing, hereinafter referred to as flat chip
3.4
finished form packing chip
formed packing chip of certain shape or waveform obtained by hotforming of flat chip
3.5
assembly lump
folded lump assembled by certain quantity of finished form packing chips through bonding or rod-penetrating, or grid plump formed by certain quantity of curved piece eliminators which are separated by stands and connected by rods
3.6
curved piece eliminators
curved sheets formed by extrusion of plastic
3.7
stand of eliminators
member used to support between curved piece eliminators
3.8
rod of eliminators
plastic rod used to fix and connect curved piece eliminators and stands
3.9
spray device
water injector, known as spray head, that can spray cooling water into fine water droplets
3.10
bracket
frame used to support the packing that is placed in a cooling tower
3.11
simple beam support
supporting form in which both ends of the assembly lump are placed on strip support
3.12
trellis net support
supporting form in which the packing adopts frame support
3.13
suspension support
the packing is simply-supported, and its supporting frame is in an installation form in which the hanger rod is suspended on the beam of water drenching layer
3.14
factory test
inspection of some basic items of product quality, which is carried out to characterize the product quality performance before they are delivered. All the technical requirements in this regulation are factory test items, except for those marked with *
3.15
type test
periodic assessment form to completely test the product quality, covering all items of product technical requirements specified in this standard
4 General
4.1 Before mass production, various plastic parts shall be subjected to test verification for their main technical performance indexes according to DL/T 933 and shall be operated for trial. The thermal performance assessment test on an industrial tower is also required for the trial of packing which shall not be promoted for use until its performance guarantee value is acceptable. See Annex A for the spacing of packing chips in different types of packing assembly lumps, the mass of assembly lump per cubic meter and the bonding and arrangement mode for adjacent chips.
4.2 Various plastic parts must meet the following basic requirements in long-term production run:
a) Free from softening and deformation at 65° water temperature.
b) Free from rupture and embrittlement under the minimum design temperature.
c) Having sufficient rigidity and strength and good aging resistance. The geometrical shape, performance index and installation & connection of various parts shall be kept stable for a long time under normal service conditions. The service life of the packing, eliminator, distribution pipe and packing bracket shall not be less than 20 years, and that of the spray device shall not be less than 12 years.
4.3 The bonding and curing performance of the packing adhesive under various ambient temperatures shall meet the bonding and assembling process requirements. The initial bonding strength of the adhesive at tensile shear shall not be less than 0.5MPa at 2h after bonding.
4.4 In addition to this standard, the plastic parts shall also comply with those specified in the national and professional regulations, codes and relevant provisions.
4.5 In general, the type test shall be carried out at least once every two years. The type test shall be carried out under any of the following conditions:
a) trial production and stereotyping appraisement of new products or for transfer-plant production of old products;
b) where there are great changes in structure, material and process which may affect the product performance;
c) where the production is resumed after a long-term shutdown;
d) where the result of factory test is greatly different from that of the previous type test;
e) where the type test is required by the national quality supervision institution.
Foreword i 1 Scope 2 Normative references 3 Terms and definitions 4 General 5 Technical requirements 5.1 Packing 5.2 Eliminator 5.3 Spray device 5.4 Distribution pipe 5.5 Packing bracket 6 Inspection 6.1 Packing 6.2 Eliminator 6.3 Spray device 6.4 Distribution pipe 6.5 Packing bracket 7 Packaging, marking, storage and transportation Annex A (Informative) Chip spacing, mass and arrangement of different types of packing assembly lumps Annex B (Normative) Test method for longitudinal shrinkage by heating flat packing chip Annex C (Normative) Test method for cold-resistant temperature (tb) by folding the packing under low temperature Annex D (Normative) Wet and hot air aging test method for plastic parts of tower Annex E (Normative) Specimen preparation for plastic parts of tower Annex F (Normative) Temperature resistance property test method for finished form packing chip Annex G (Normative) Load test method for packing assembly lump Annex H (Normative) Dimension change rate test method for curved piece eliminators Annex I (Normative) Tension rupture test method for rod of curved eliminators Annex J (Normative) Tension rupture test method for stand of curved eliminators Annex K (Normative) Destructive test of spray device deflector (ring) Annex L (Normative) Test method of deflection of packing bracket
Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is developed in accordance with the rules given in GB/T 1.1-2009 Directives for standardization - Part 1: Structure and drafting of standards.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.
This standard replaces DL/T 742-2001 Technical specification for plastic parts of cooling tower. In addition to editorial changes, the following main technical changes have been made with respect to DL/T 742-2001:
——Contents relevant to design, operation and test in the original standard that are repeated in other professional standards are deleted;
——The product quality standard for the packing bracket is added;
——Contents of product quality inspection, acceptance, quality standard, packaging, marking, storage and transportation are added.
This standard was proposed by the China Electricity Council.
This standard is under the jurisdiction of the Technical Committee on Power Station Steam Turbine of Standardization Administration of Power Industry (DL/TC 07).
This standard replaces DL/T 742-2001 Technical specification for plastic parts of cooling tower from the implementation date hereof.
This standard was firstly issued in 2001, and this is the first revision.
During the process of implementing this standard, the relevant comments and recommendations, whenever necessary, can be fed back to the Standardization Center of the China Electricity Council (No.1, 2nd Lane, Baiguang Road, Beijing, 100761, China).
Quality standard of plastic parts for wet cooling tower
1 Scope
This standard specifies basic requirements for the manufacture, quality inspection, packaging, storage and transportation of plastic parts of wet cooling tower.
It is applicable to plastic parts such as film packing, distribution pipe and eliminator made of PVC plastics, spray device made of engineering plastics, and packing bracket made of fiber-reinforced plastics (glass fiber reinforced plastics).
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 1033.1 Plastics - Methods for determining the density of non-cellular plastics - Part 1: Immersion method, liquid pyknometer method and titration method
GB/T 1040.1 Plastics - Determination of tensile properties - Part 1: General principles
GB/T 1040.3 Plastics - Determination of tensile properties - Part 3: Test conditions for films and sheets
GB/T 1446 Fiber-reinforced plastics composites - The generals for determination of properties
GB/T 1447 Fiber-reinforced plastics composites - Determination of tensile properties
GB/T 1449 Fibre-reinforced plastic composites - Determination of flexural properties
GB/T 1633 Plastics - Thermoplastic materials - Determination of Vicat softening temperature (VST)
GB/T 1843 Plastics - Determination of izod impact strength
GB/T 2406.1 Plastics - Determination of burning behaviour by oxygen index - Part 1: Guidance
GB/T 2406.2 Plastics - Determination of burning behaviour by oxygen index - Part 2: Ambient-temperature test
GB/T 2828.1 Sampling procedures for inspection by attributes - Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection
GB/T 3854 Test method for hardness of reinforced plastics by means of a Barcol impresser
GB/T 4219.1 Unplasticized poly (vinyl chloride) (PVC-U) piping system for industrial applications - Part 1: Pipes
GB/T 6671 Thermoplastics pipes - Determination of longitudinal reversion
GB/T 8802 Thermoplastics pipes and fitting - Determination of vicat softening temperature
GB/T 8804.1 Thermoplastic pipes - Determination of tensile properties - Party 1: General test method
GB/T 8804.2 Thermoplastic pipes - Determination of tensile properties - Part 2: Pipes made of unplasticized poly (vinyl chloride) (PVC-U), chlorinated poly (vinyl chloride) (PVC-C) and high-impact poly (vinyl chloride)(PVC-HI)
GB/T 8806 Plastics piping systems - Plastics components - Determination of dimensions
QB/T 1130 Test method for right angle tearing property of plastics
QB/T 2803 Determination of deflection for rigid plastic pipes
DL/T 933 Test methods for determining the performance of cooling tower of transfer packing, drift eliminator and sprayer
3 Terms and definitions
For the purpose of this standard, the following terms and definitions apply.
3.1
poly vinyl chloride plastics; PVC
material produced by extrusion of PVC resin and various additives
3.2
service life
service term of the plastic parts of cooling tower to meet their technical and economical requirements under normal service conditions
3.3
flat packing chip
flat and smooth plastic sheet adopted for the hotforming of plastic packing, hereinafter referred to as flat chip
3.4
finished form packing chip
formed packing chip of certain shape or waveform obtained by hotforming of flat chip
3.5
assembly lump
folded lump assembled by certain quantity of finished form packing chips through bonding or rod-penetrating, or grid plump formed by certain quantity of curved piece eliminators which are separated by stands and connected by rods
3.6
curved piece eliminators
curved sheets formed by extrusion of plastic
3.7
stand of eliminators
member used to support between curved piece eliminators
3.8
rod of eliminators
plastic rod used to fix and connect curved piece eliminators and stands
3.9
spray device
water injector, known as spray head, that can spray cooling water into fine water droplets
3.10
bracket
frame used to support the packing that is placed in a cooling tower
3.11
simple beam support
supporting form in which both ends of the assembly lump are placed on strip support
3.12
trellis net support
supporting form in which the packing adopts frame support
3.13
suspension support
the packing is simply-supported, and its supporting frame is in an installation form in which the hanger rod is suspended on the beam of water drenching layer
3.14
factory test
inspection of some basic items of product quality, which is carried out to characterize the product quality performance before they are delivered. All the technical requirements in this regulation are factory test items, except for those marked with *
3.15
type test
periodic assessment form to completely test the product quality, covering all items of product technical requirements specified in this standard
4 General
4.1 Before mass production, various plastic parts shall be subjected to test verification for their main technical performance indexes according to DL/T 933 and shall be operated for trial. The thermal performance assessment test on an industrial tower is also required for the trial of packing which shall not be promoted for use until its performance guarantee value is acceptable. See Annex A for the spacing of packing chips in different types of packing assembly lumps, the mass of assembly lump per cubic meter and the bonding and arrangement mode for adjacent chips.
4.2 Various plastic parts must meet the following basic requirements in long-term production run:
a) Free from softening and deformation at 65° water temperature.
b) Free from rupture and embrittlement under the minimum design temperature.
c) Having sufficient rigidity and strength and good aging resistance. The geometrical shape, performance index and installation & connection of various parts shall be kept stable for a long time under normal service conditions. The service life of the packing, eliminator, distribution pipe and packing bracket shall not be less than 20 years, and that of the spray device shall not be less than 12 years.
4.3 The bonding and curing performance of the packing adhesive under various ambient temperatures shall meet the bonding and assembling process requirements. The initial bonding strength of the adhesive at tensile shear shall not be less than 0.5MPa at 2h after bonding.
4.4 In addition to this standard, the plastic parts shall also comply with those specified in the national and professional regulations, codes and relevant provisions.
4.5 In general, the type test shall be carried out at least once every two years. The type test shall be carried out under any of the following conditions:
a) trial production and stereotyping appraisement of new products or for transfer-plant production of old products;
b) where there are great changes in structure, material and process which may affect the product performance;
c) where the production is resumed after a long-term shutdown;
d) where the result of factory test is greatly different from that of the previous type test;
e) where the type test is required by the national quality supervision institution.
Contents of DL/T 742-2019
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 General
5 Technical requirements
5.1 Packing
5.2 Eliminator
5.3 Spray device
5.4 Distribution pipe
5.5 Packing bracket
6 Inspection
6.1 Packing
6.2 Eliminator
6.3 Spray device
6.4 Distribution pipe
6.5 Packing bracket
7 Packaging, marking, storage and transportation
Annex A (Informative) Chip spacing, mass and arrangement of different types of packing assembly lumps
Annex B (Normative) Test method for longitudinal shrinkage by heating flat packing chip
Annex C (Normative) Test method for cold-resistant temperature (tb) by folding the packing under low temperature
Annex D (Normative) Wet and hot air aging test method for plastic parts of tower
Annex E (Normative) Specimen preparation for plastic parts of tower
Annex F (Normative) Temperature resistance property test method for finished form packing chip
Annex G (Normative) Load test method for packing assembly lump
Annex H (Normative) Dimension change rate test method for curved piece eliminators
Annex I (Normative) Tension rupture test method for rod of curved eliminators
Annex J (Normative) Tension rupture test method for stand of curved eliminators
Annex K (Normative) Destructive test of spray device deflector (ring)
Annex L (Normative) Test method of deflection of packing bracket
