Dismantling joints are a key component of modern piping systems, perfectly combining “ease of installation” and “functional stability”; they combine the modular connection characteristics of flanges with the displacement compensation capability of expansion joints, and are specially designed to solve the problems of rapid installation and post-maintenance of piping equipment (e.g. pumps, valves).
The core value of a Dismantling Joint lies in the combination of “convenience” and “functionality“. It provides a detachable connection like a flange, absorbs axial displacement like an expansion joint, and includes limiting/anti-blowout features. It is a key component in modern pipeline systems for achieving modular design, quick installation, and convenient maintenance.
This is its most fundamental and unique purpose. Unlike welded or fixed flange connections, the bolts of a dismantling joint are loosely mounted on the pipe flanges.
During installation: The joint body can first be fixed to one pipe section. The other pipe’s flange holes can then be easily aligned, and bolts can be inserted and tightened without requiring precise initial alignment.
During maintenance: When valves, pumps, or pipeline sections need replacement, simply loosening the joint’s bolts allows the pipes to be axially moved and separated. This avoids the need for extensive cutting or disassembly of the entire pipeline, significantly saving time and labor.
Axial displacement compensation: It can absorb axial (along the pipe direction) expansion and contraction caused by thermal changes.
Minor angular deflection compensation: It can tolerate slight misalignment or angular deflection between pipes.
Примечание: It is generally not intended for compensating significant lateral displacement (perpendicular to the pipe direction). Its capability in this regard is less than that of hinged or gimbal-type expansion joints.
The joint contains internal sealing rings (typically made of rubber, such as NBR or EPDM, selectable based on the medium). When bolts are tightened, the rings compress to ensure the pipeline medium (water, oil, gas, etc.) does not leak.
Many dismantling joints (especially the “limiting type”) feature limit bolts or devices. When the pipeline is subjected to internal pressure and resulting thrust force, these limiters prevent the joint from being over-extended, protecting the seals and preventing pipe separation to ensure system safety.
Dismantling joints are widely used in:
Water supply and wastewater treatment systems
HVAC (Heating, Ventilation, and Air Conditioning) systems
Chemical and industrial pipelines
Inlets/outlets of pumps, valves, and water meters (facilitating installation and maintenance of this equipment)
Pipeline sections requiring frequent disassembly and maintenance
AF Type: Single-flange loose sleeve limiting expansion joint (one end flanged, one end for welding to the pipe).
BF Type: Double-flange loose sleeve limiting expansion joint (both ends have flanges, the most common type).
B2F Type: Double-flange loose sleeve transfer force joint (can transmit pipeline thrust forces in addition to compensation and disassembly functions, protecting equipment).
Dimensions в мм
| РАЗМЕР | D2 | D4 | D5 | ØdxN | L1 | L2 | |
| Ду40 | 56 | 110 | 150 | M16×280 | 4 | 190 | 280 |
| Ду50 | 66 | 125 | 165 | M16×280 | 4 | 190 | 280 |
| DN60 | 77 | 135 | 175 | M16×280 | 4 | 190 | 280 |
| Ду65 | 82 | 145 | 185 | M16×280 | 4 | 190 | 280 |
| DN80 | 98 | 160 | 200 | M16×310 | 8 | 210 | 310 |
| Ду100 | 118 | 180 | 220 | M16×310 | 8 | 210 | 310 |
| Ду125 | 144 | 210 | 250 | M16×310 | 8 | 210 | 310 |
| Ду150 | 170 | 240 | 285 | M20×320 | 8 | 210 | 320 |
| Ду200 | 222 | 295 | 340 | M20×340 | 8 | 230 | 340 |
| Ду250 | 274 | 350 | 400 | M20×360 | 12 | 230 | 360 |
| DN300 | 326 | 400 | 455 | M20×360 | 12 | 235 | 360 |
| Ду350 | 378 | 460 | 505 | M20×360 | 16 | 245 | 360 |
| DN400 | 429 | 515 | 565 | M24×370 | 16 | 265 | 370 |
| Ду450 | 480 | 565 | 615 | M24×390 | 16 | 265 | 390 |
| DN500 | 532 | 620 | 670 | M24×390 | 20 | 270 | 390 |
| DN600 | 632 | 725 | 780 | M27×410 | 20 | 285 | 410 |
| DN700 | 735 | 840 | 895 | M27×410 | 24 | 285 | 410 |
| DN800 | 842 | 950 | 1015 | M30×460 | 24 | 320 | 460 |
| DN900 | 945 | 1050 | 1115 | M30×460 | 28 | 320 | 460 |
| DN1000 | 1048 | 1160 | 1230 | M33×480 | 28 | 340 | 480 |
| DN1100 | 1152 | 1270 | 1340 | M33×480 | 32 | 340 | 480 |
| DN1200 | 1255 | 1380 | 1455 | M36×520 | 32 | 360 | 520 |
| DN1400 | 1462 | 1590 | 1675 | M39×560 | 36 | 380 | 560 |
| DN1500 | 1565 | 1700 | 1785 | M39×590 | 36 | 400 | 590 |
| DN1600 | 1668 | 1820 | 1915 | M45×600 | 40 | 420 | 600 |
| DN1800 | 1875 | 2020 | 2115 | M45×640 | 44 | 420 | 640 |
| DN2000 | 2082 | 2230 | 2325 | M45×640 | 48 | 430 | 640 |