SC/T 4017-2020 in English

Standard Background and Scope of Application

SC/T 4017-2020 is my country's first industry technical standard for plastic fish cages, proposed by the Fisheries Administration of the Ministry of Agriculture and Rural Affairs and managed by the National Technical Committee for Aquatic Products Standardization. This standard fills the gap in the application of HDPE materials in aquaculture facilities and regulates the entire process of designing and manufacturing guardrail-type plastic fish cages with a circumference of ≥20m.

Definition of core terms

Key technical requirements

1. Dimension tolerance control

The standard stipulates strict dimensional deviation rates: circumference deviation ≤3%, box height deviation ≤4.5% (＞2m), anti-jump net height deviation ≤9%. The actual measurement adopts the average method of secondary measurement, and the calculation formula is: Δ=(measured value-nominal value)/nominal value×100%

2. Material performance indicators

Assembly specification points

1. Walkway board installation: gap control (width ≤20mm, length ≤30mm), anti-slip pattern depth ≥1mm
2. Net sewing: adopt the double-thread twisted sewing method specified in SC/T 4005, and the node strength retention rate ≥85%
3. Anchoring system: The breaking strength of polypropylene rope shall be ≥35kN (GB/T 30668), and the breaking load of anchor chain shall be ≥2 times of the design value

Analysis of marking system

The standard has established a complete coding system. For example:
HDPE-PAN-SS-120.0m×8.0m-60mm×10mm×5mm+0.8m-PA23tex×75-60mmJB-PE100-SDR17-d400mm/en23.7mm+3033kN
They respectively represent: material - net type - size - anti-jump net - net parameters - floating tube specifications, among which SDR17 is the standard size ratio, which directly affects the pressure bearing capacity of the pipe.

Implementation suggestions

1. Design stage

PE100 grade HDPE pipes are preferred, and the SDR value should be calculated according to the water depth pressure:
SDR26 can be used in shallow water areas (<5m), and SDR11 is recommended in deep water areas (>10m)

2. Production quality control

Three key monitoring points:
- Ring stiffness of the floating pipe welding ≥8kN/m²
- Walkway slab rib thickness error ≤±0.5mm
- Coefficient of variation of net foot length ≤5%

3. Operation and maintenance management

Establish a quarterly inspection system:
- Measure the change in the draft of the floating pipe every month
- Check the elongation of the anchor rope every quarter (replace if it exceeds 10%)
- Perform a comprehensive buoyancy check every year