(borehole) CASING thr. MxF, PVC, 4"½ 125x113mm NP12.5, 3m
Valid Article
(borehole) CASING thr. MxF, PVC, 4"½ 125x113mm NP12.5, 3m
Form
Borehole PVC casing, nominal diameter 4"1/2, with a threaded male connection on one end and a female threaded connection on the other. Should be drinking water quality.
- Length: 3m
- Inner diameter: 113mm
- Outer diameter: 125mm
- Nominal pressure: NP12.5
- Non-screened tube
Usually blue.
Per piece.
Fit
To be screwed onto 4"1/2 threaded coupling male on one end, female on the other. Several types of thread are available. (Gas thread ‘withworth', Trapezoidal thread)
The thread does not require the use of sealants (mastic, glue, tow, etc.).
Function
As the risk of collapse can be significant, the casing is put in place as quickly as possible.
The casing or catchment plan (length and position of the solid tubes and strainers) is established according to the geological section of the borehole where the different “layers” of land and the inflows of water are noted, observed visually during the drilling and through sampling.
In order to guarantee a good positioning of the tubes in the hole and therefore a good distribution of the filter mass around the strainers, it is recommended to instal centering devices around the tubes.
For more information see: "Water, Hygiene and Sanitation for populations at risk". Action against Hunger. Chapter 8 drilling.