NATURAL BEND RADIUS IN PEXGOL PIPES
To create turns with Pexgol pipes laid inside trenches, above the ground or over pipe bridges, the pipe can be bent according to table 49.1 “Natural bending radius”.
The values are relevant for installations at all ambient temperatures up to 40°C.
For pipe diameters lower than 110 mm use the values of the 110 mm pipes at all pressure classes.
Field bending involves excavating the trench to the appropriate bend radius, then sweeping or pulling the pipe string into the required bend and placing it in the trench.
This kind of pipeline design, which takes advantage of the natural flexibility of the pipe, reduces the number of connections and lowers head losses.
Observe appropriate safety precautions during field bending. Considerable force might be required to field bend the pipe, and the pipe could spring back forcibly if the restraint slips are inadvertently released while bending.
Designing Pexgol Pipes with Natural Bends
When designing Pexgol pipes with natural bends, it is recommended to consult with our field service personnel. Take into consideration that to bend the pipe on site, suitable facilities are required. Take into consideration the space required to insert the pipe into the construction, as well as the possibility to exert bending moment of the pipe.
“Natural” bends of Pexgol pipes
Table 49.1 shows bending radius for Pexgol pipes. If possible, design the pipeline with larger bending radii to facilitate pipe bending on site.
The pipe bends must be fixed with fixpoint clamps before and after each bend. For pipe diameters of 280 mm and larger, the pipe bends must be supported in the centre in addition to the two fix points noted. For additional details please contact the Golan’s application engineer.
Route change of Pexgol pipes inside trenches
For a route change in buried pipes, it is recommended to dig the trench with the minimum natural bending radius listed in Table 49.1.
Table 49.1: Natural Bending Radius
Pipe OD (mm) | Class 6 | Class 8 | Class 10 | Class 12 | Class 15 | Class 19 | Class 24 | Class 30 |
---|---|---|---|---|---|---|---|---|
110 | 13.5D | 10.5D | 8D | 6.5D | 5D | 4.5D | 3.5D | 3D |
125 | 16.5D | 13.5D | 10D | 8.5D | 6.5D | 5.5D | 4.5D | 3.5D |
140 | 16.5D | 13.5D | 10D | 8.5D | 6.5D | 5.5D | 4.5D | 3.5D |
160 | 16.5D | 13.5D | 10D | 8.5D | 6.5D | 5.5D | 4.5D | 3.5D |
180 | 16.5D | 13.5D | 10D | 8.5D | 6.5D | 5.5D | 4.5D | 3.5D |
200 | 16.5D | 13.5D | 10D | 8.5D | 6.5D | 5.5D | 4.5D | 3.5D |
225 | 16.5D | 13.5D | 10D | 8.5D | 6.5D | 5.5D | 4.5D | 3.5D |
250 | 20D | 16D | 12D | 10D | 8D | 6.5D | 5D | 4D |
280 | 20D | 16D | 12D | 10D | 8D | 6.5D | 5D | 4D |
315 | 27D | 21.5D | 16D | 13.5D | 11D | 8.5D | 7D | 5.5D |
355 | 27D | 21.5D | 16D | 13.5D | 11D | 8.5D | 7D | 5.5D |
400 | 34D | 27D | 20D | 17D | 13D | 10.5D | 8.5D | 7D |
450 | 34D | 27D | 20D | 17D | 13D | 10.5D | 8.5D | 7D |
500 | 40D | 32D | 24D | 20D | 16D | 13D | 10D | 8D |
560 | 43D | 34.5D | 26D | 22D | 17D | 13.5D | 11D | 9D |
630 | 47D | 37D | 28D | 23.5D | 19D | 14.5D | 12D | 9.5D |
710 | 50D | 40D | 30D | 25D | 20D | 16D | 13D | 10D |