Four Key Connection Types
|
Fixed Coupling (Rigid Joint) |
Variable Coupling (Quick-Release Joint) |
NPT Thread (National Pipe Thread) |
G Thread (Guan Pipe Thread) |
|
| Feature |
Non-rotatable (no movement when twisting the middle groove) |
Middle groove rotates for easy disassembly |
Tapered shape (narrow top, wider base for self-sealing) No groove |
Straight-cut threads (no taper) Visible groove |
| Application |
High-pressure; Permanent connections |
Maintenance-friendly parts | / | |
| Advantage | / |
High-pressure sealing |
Quick assembly |
|
| Sealing Method | / | Anaerobic Adhesive | O-Ring | |
| Typical Connections | / | Breakaway Valve/Nozzle | Hose Coupler/Sight Glass | |
3-Second Identification Guide
Step 1: Fixed or Variable?
Twist the middle groove → Moves = Variable Coupling, Stays = Fixed Coupling
Step 2: NPT or G Thread?
Check the top: Groove = G Thread (Blue Arrow); No groove = NPT (Red Arrow)
Check the shape: Tapered = NPT (Red Profile Containment Border); Straight = G (Green Profile Containment Border)
Selection Tips for Gas Station Equipment
High-pressure lines: Use NPT + Fixed Coupling for leak-proof security
Serviceable parts: Opt for G Thread + Variable Coupling for easy maintenance
Global compatibility: Export equipment should support dual-thread standards
Why Do Professionals Care?
✔️ Sealing: NPT threads handle up to 30MPa in Fuel Dispensers
✔️ Efficiency: Variable couplings cut Petrol Pump maintenance time by 50%
✔️ Cost Control: Wrong threads may strip, tripling repair costs
Master these essentials to become a fuel-connection expert!
For technical support, consult Eaglestar.
Eaglestar your 100% trust worthy gas station equipment factory!