Basic Product Technical Parameters
70mm PVC pipe fittings are core components of modern piping engineering, and their specifications strictly comply with GB/T 5836-2018 standard system, key technical specifications are as follows:
Dimensional Accuracy Standards:
Nominal Outside Diameter: 70.0 ± 0.3mm (Grade A control range)
Wall Thickness Tolerance: ± 0.2mm (SDR26 series standard wall thickness 2.3mm)
Socket Depth: 48-52mm (including the adhesive groove structure)
Material Performance Parameters:
Density: 1.38-1.42 g/cm³ (PVC-U material)
Elastic Modulus: 2800-3200 MPa (tested at 23°C)
Coefficient of Thermal Expansion: 0.07 mm/(m·K) (compensation required)
Mechanical Performance Requirements:
Short-Term Hydraulic Strength: 1.5 MPa for 1 hour with no leakage
Drop Hammer Impact Resistance: No cracking when subjected to a 5kg hammer at a height of 2m at -10°C
Ring Stiffness Grade: SN4 (≥ 4 kN/m²)
Product Categories and Technical Features
Structural Connector Series
Straight Connector Assembly:
Double Waterstop Design (30% Improved Sealing)
Working Pressure Classification:
| Pressure Level | Test Pressure | Applications |
|———-|———|——————|
| PN0.6 | 0.9MPa | General Building Drainage |
| PN1.0 | 1.5MPa | Pressurized Drainage System |
| PN1.6 | 2.4MPa | Special Industrial Applications |
Elbow Series:
90° Elbow:
Long Radius (R=1.5D=105mm): Head Loss Coefficient 0.5
Short Radius (R=1D=70mm): Head Loss Coefficient 0.8
45° Elbow: Optimized flow guide design (reducing turbulence by 60%)
Tee System:
Flow Distribution Characteristics:
Q_{Branch Pipe} = 0.55 times Q_{Main Pipe} quad (Equal Diameter Tee)
Clean Port Specifications:
Opening Angle: 110 ± 5°
Sealing Pressure: ≥ 0.05 MPa
Functional Expansion Accessories
Flange Adapter:
Structural Parameters:
Flange Standard: GB/T 9119 PN10
Bolt Holes: 4 x Φ14mm (uniformly spaced 145mm PCD)
Sealing Surface: RF Raised Surface (Ra ≤ 3.2μm)
Expansion Joint Assembly:
Compensation Calculation:
ΔL = α times L times ΔT
(α = 0.07mm/m·K; recommended every 20m)
Limiting Structure: Double Nut Lock (Anti-Pullout Design)
Engineering Application Technical Specifications
Building Drainage System
System Design Key Points:
Riser Flow Velocity Control: 1.5-3.0 m/s (Optimal Operating Conditions)
Ventilation System Configuration: Combined ventilation pipes installed every 8 floors
Noise Control: Silencer elbows + rubber supports (≤45 dB)
Support System Specifications:
| Pipe Diameter (mm) | Horizontal Support (m) | Vertical Support (m) | Support Type |
|———-|————-|————-|—————-|
| 70 | 1.0 | 1.5 | With EPDM Shock Absorber |
Agricultural Irrigation Project
Hydraulic Calculation Model:
h_f = 10.67 × L × Q^{1.852} × C^{-1.852} × D^{-4.87}
(C = 150; D = inner diameter in meters)
Frost-resistant design:
Buried depth requirement: ≥ frozen ground + 0.3m
Drainage slope: ≥ 0.005 (slope toward the drain well)
Installation Process Standards
Gluing Technical Specifications
Surface Treatment Process:
Cutting Surface Angle Deviation: ≤1.5°
Chamfer Dimensions: 15° × 2mm (to ensure smooth insertion)
Cleanliness Requirements: No visible stains after wiping with alcohol
Gluing Procedure:
Glue Dosage: 5 ± 1g/joint (70mm gauge)
Curing Time:
| Ambient Temperature (°C) | Initial Setting Time (min) | Full Cure (h) |
|————|—————|————-|
| 5-15 | 8-10 | ≥6 |
| 15-30 | 3-5 | ≥4 |
Mechanical Connection Process
Flange Installation Torque:
| Bolt Specifications | Torque Value (N·m) | Tightening Sequence |
|———-|————|—————-|
| M12 | 45-50 | Three alternating diagonal passes |
Rubber Seal Compression: 25-30% (cross-section diameter)
Quality Inspection and Acceptance Standards
Factory Inspection Items
Dimensional Inspection:
Roundness Error: ≤0.5% of nominal diameter
Wall Thickness Deviation: ≤±10% of nominal value
Pressure Test:
Burst Pressure: ≥4 times the working pressure
Seal Test: 1.5 times the working pressure, hold for 5 minutes
On-site Acceptance Standards
Glued Joint Inspection:
Glue Seam Width: 0.1-0.3mm (uniform and continuous)
Socket Depth: Marked line fully submerged
System Pressure Test:
| System Type | Test Pressure | Duration | Pressure Drop Requirement |
|————|———|———-|———-|
| Drainage System | 0.15MPa | 30 minutes | ≤0.02MPa |
| Pressure System | 1.5PN | 1 hour | ≤5% |
This technical document covers the entire process of design selection, construction and installation, acceptance, and maintenance. Calculations should be reviewed and verified based on the specific project conditions. It is recommended to use reinforced accessories (wall thickness increased by 20%) at key nodes and retain 5-10% spare parts for maintenance and replacement.
