I. Principle of grooved pipeline technology
1. Basic structure
The core of the grooved pipeline system consists of three parts:
Groove processing: a special groove rolling machine is used to press out an annular groove at the end of the pipe.
Groove pipe fittings: including rigid coupling (for fixed connection) and flexible coupling (allowing certain displacement).
Sealing elements: rubber gaskets (EPDM, NBR, etc.) provide sealing and adapt to temperature and pressure changes.
2. Connection mechanism
After the groove is processed at the end of the pipe, the sealing ring is embedded in the clamp.
The clamp is tightened by bolts to bite the pipeline groove, forming a dual guarantee of mechanical locking and elastic sealing.
II. The core advantages of grooved connection
1. Improved installation efficiency
No welding/flange processing is required: traditional welding requires professional technicians and long cooling, while grooved connection only requires cutting, grooving and assembly, shortening the construction period by more than 60%.
Modular construction: pipelines can be prefabricated and assembled on site, which is especially suitable for renovation projects with limited space.
2. Enhanced system reliability
Seismic and displacement resistance: Flexible coupling allow axial 5° deflection and radial displacement, effectively absorbing earthquake or thermal expansion and contraction stress.
Sealing durability: The rubber gasket is evenly compressed under the bolt preload, and the service life can reach more than 20 years (UL/FM certified).
3. Significant economic efficiency
Reduced labor costs: No need for expensive welders, ordinary workers can operate after training.
Optimized maintenance costs: When local damage occurs, only the coupling needs to be replaced, and there is no need to cut the pipe.
III. The entire process of grooved pipe installation
1. Preliminary preparation
Tool list:
Grooving machine (electric or hydraulic), cutting machine, deburring tool.
Torque wrench, sealant, lubricant (food grade glycerin).
Material inspection:
The pipe material must meet the groove processing requirements (carbon steel, stainless steel, copper pipe, etc.).
Confirm that the clamp type (rigid/flexible) matches the pipe pressure level.
2. Groove processing steps
Pipe cutting:
Use a cutting machine with a guide rail to ensure that the port is flush and the deviation is ≤1.6mm.
Remove burrs on the inner and outer walls to prevent damage to the sealing ring.
Grooving operation:
Adjust the groove to the outer diameter of the pipe, start it and push it at a uniform speed until the groove is formed.
The standard groove depth is 1.5~2.0mm, and the width is consistent with the clamp size.
3. Coupling assembly
4.Install the sealing ring:
Put the rubber gasket into the inner groove of the clamp and apply lubricant evenly.
Avoid excessive stretching that may cause seal failure.
Pipe docking:
Align the two sections of the pipe, leaving a gap of 3~5mm (to compensate for thermal expansion).
Tighten the bolts:
Tighten the bolts twice in diagonal order, and refer to the manufacturer’s specifications for the final torque value (for example: 90~100N·m for a 4-inch clamp).
IV. Industry application scenarios and cases
Requirement characteristics: need to be installed quickly and withstand high pressure (≥12bar).
Scheme design:
Use galvanized steel pipe + rigid coupling, with EPDM sealing ring (high temperature resistant to 120℃).
Case: In a high-rise office building project, the groove system saves 40% of working hours compared with traditional welding.
2. Industrial cooling water circulation
Requirement characteristics: Frequent pipeline vibration requires anti-fatigue design.
Scheme design:
Use stainless steel pipe + flexible coupling, allowing ±2mm radial displacement.
Case: After the chemical plant cooling tower pipeline was renovated, the leakage rate dropped by 90%.
3. Food and beverage industry
Requirement characteristics: high hygiene standards, easy-to-clean structure required.
Scheme design:
Select 316L stainless steel clamp, and the sealing ring meets FDA standards.
The inner wall of the clamp is polished to avoid microbial growth.
V. Key considerations and troubleshooting
1. Common installation errors
Groove too deep/shallow: causes the clamp to fail to lock or the seal to be over-compressed.
Uneven bolt torque: Over-tightening on one side causes stress concentration and accelerates the aging of the gasket.
2. Maintenance points
Regular inspections: Check the bolt torque every six months and recalibrate when it is loose.
Replace the seal: If hardening or cracking is found, replace it immediately (spare parts inventory ≥ 10% is recommended).
3. Standard compliance
International certification: Choose products that have passed UL 213, FM 1680 and other certifications.
Local specifications: For example, China’s GB 5135.11-2006 has mandatory requirements for grooved parts for fire protection systems.
VI. Comparison between groove system and other connection methods
| Connection method | Installation speed | Seismic resistance | Maintenance cost | Applicable scenarios |
| Groove type | Fast (1 hour/10 joints) | Excellent | Low | Fire protection, industrial, commercial buildings |
| Welding | Slow (including cooling time) | Poor | High | High pressure, high temperature pipelines |
| Flange | Medium | Medium | Medium | Large pipe diameter, frequent disassembly required |
VII. Future Development Trends
Intelligent tools: Electric torque wrenches combined with the Internet of Things to monitor bolt preload in real time.
Environmentally friendly materials: Bio-based rubber seals (such as DuPont™ EPM Green Energy Series) reduce carbon footprint.
Modular design: Prefabricated grooved pipe units for “plug-and-play” installation.