Rail plastic dowel
Rail plastic dowel is a counter fastener for sleeper screws and track bolts. It is pre-imbedded into concrete or wooden sleeper tie, where screw spikes, guide plates and rail clips are installed into the rail track. Rail plastic dowel can be called plastic sleeve, plastic insert, concrete dowel, and concrete insert.
Functions of rail plastic dowels
Rail plastic dowel functions as the fastening foundation, because it needs to be pre-inserted into the concrete sleeper before assembling the rail fastening system. It work with screw spike and bolts to guarantee the good connection between rail fastening system and concrete sleeper,
For another, rail plastic dowel has similar function as rail pad and rail insulator, serving to insulate the fastener from ties. In this regard, the strength and fatigue life of rail dowel have great impact on the whole railroad.
In rail fastening system, the collaboration of anchor bolts and imbedded plastic dowel makes the tie plate tightly fastened to rail track and sleeper. Meanwhile, with rail clips ensuring a large elasticity range, the rail bolts are free from getting loose, thus reducing the maintenance work.
Classifications of Rail Plastic Dowel
Rail plastic sleeves are frequently used in SKL fastening system. They can be classified according to materials, like PA66 or HDPE. The following chart present technical specifications of different Rail Plastic Dowel.
| Check Item | STANDARD | ||||||
|---|---|---|---|---|---|---|---|
| 207 | 111 | WJ-2 | X2 | DJK-1 | SK114A | SKL14-D13-B | |
| Length(mm) | 110±1 | 119±0/2 | 135±2/1 | 130±0.5 | 130±0.5 | 165±1 | 165±1 |
| Inner Pole Length(mm) | / | / | / | / | / | / | / |
| Outer Dia(mm) | 53±0.5 | 35±1/0 | 24.5±0.3/0 | 44±0.5/0.3 | 39.5±0.7/0.3 | 39±0.6/0.2 | 39.5±0.6/0.2 |
| Inner Dia(mm) | 31±0.5/0.1 | 25±0.5 | 31±0.5/0.3 | 28±0.5/0.3 | 25±0.15 | 25±0.5/0 | 24.5±0.3/0 |
| Position Hole Inner Dia(mm) | / | / | / | / | / | / | / |
| Bottom Width(mm) | / | / | / | / | / | / | / |
| Verticality | ≤0.5 | ≤0.5 | ≤0.5 | ≤0.5 | ≤0.5 | ≤0.5 | ≤0.5 |
| Drainage Rate(%) | ≥0.5 | ≥0.5 | ≥0.5 | ≥0.5 | ≥0.5 | / | / |
| Pulling Strength(kN) | ≥80 | ≥50 | ≥50 | ≥50 | ≥50 | ≥75 | ≥75 |
| Insulation Resistance(Ω) | ≥1*10^8 | ≥1*10^8 | ≥1*10^8 | ≥1*10^8 | ≥1*10^8 | / | / |
| Rockwell hardness(HRR) | ≥95 | ≥105 | ≥105 | ≥105 | ≥105 | / | / |
