This standard specifies the classification and designation, requirements, test methods, inspection rules, marking, packaging, transportation and storage of middle and fine bubble diffusers.
This standard is applicable to the middle and fine bubble diffusers (hereafter referred to as diffusers) for biological sewage treatment and is also applicable to the diffusers for other purposes, such as transferring oxygen to the eutrophic water body and aquiculture water body in the environment.
2 Normative References
The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments to (excluding amending errors in the text), or revisions of, any of these publications do not apply. However, all parties coming to an agreement according to this standard are encouraged to study whether the latest edition of the normative document is applicable. For undated references, the latest edition of the normative document applies.
GB/T 699 Quality Carbon Structural Steels - Technical Specification
GB/T 1220 Stainless Steel Bars
GB 3452.1 Fluid Systems - Sealing Devices - O-rings - Inside Diameters, Cross-sections, Tolerances and Size Identification Code
GB/T 3672-1992 Dimensional Tolerances for Moulded Extruded and Calendered Solid Rubber Products
GB/T 5836.1 Unplasticized Polyvinyl Chloride Pipes for Drainage in Buildings
GB/T 5836.2 Unplasticized Polyvinyl Chloride Pipes for Drainage in Buildings
GB/T 9476 Plastic Coated Pipe
GB/T 13306 Plates
CJ/T 3015.1-1993 Fine Bubble Aerator for Wastewater Treatment
CJ/T 3015.2-1993 Oxygen Transfer Measurement of Aerators in Clean Water
CJ/T 3015.4-1996 Openable Middle and Fine Bubble Diffuser for Wastewater Treatment
3 Terms and Definitions
For the purpose of this standard, the following terms and definitions apply.
3.1 Standard ventilation flow
Volume of the air transferred by each diffuser to the clear water in unit time under standard condition (20℃, 101.325kPa) and test condition (service area: 0.5m2, aeration depth: 4m), m3/h.
3.2 Maximum bubble diameter
The equivalent diameter of the largest capillary channel measured when the test gas appears the first bubble on the specimen surface through the specimen immerged into test liquid.
3.3 Porosity
Percentage of volume of open pore (connected with atmosphere) on diffuser plate in its total volume.
