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MURLAC SILT TUBES & DEWATERING BAGS

Murlac Silt Dewatering tubes and Dewatering Bags,  are available in a range of sizes. Please select from the options below for your application. Silt Tubes are designed for larger dewateing projects, whereas Silt Bags and Silt Socks are designed for smaller capacities up to 5m3. We will not be beaten on quality or price.

MATERIAL SPECIFICATION:

Silt Tubes are manufactured using two main types of geotextile, woven and non-woven, sometimes referred to as needle-punched material. The two main differences between the two types of material is the tensile strength and the pore opening size. Woven materials have a higher tensile strength in the material which allows for larger circumference bags to be manufactured along with the ability to stack the silt tubes to make maximum use of the work area. Non-woven materials have a smaller pore opening size than woven materials, therefore will contain finer particles. However you should take into account that the non-woven tubes may take longer to dewater compared to woven tubes.

 

Material Pore opening size Maximum circumference Stackable
Non Woven 40 90 microns 10m No
Non Woven 50 80 microns 10m No
Non Woven 60 72 microns 15m Yes – up to 15m circ only
Woven 40 180 microns 10m No
Woven 60 275 microns 10m No
Woven 80 300 microns 25m Yes – up to 15m circ only
Woven 100 230 microns 25m Yes – up to 15m circ only

HOW DO THEY WORK?

Sediment is pumped into the silt tubes using the integrated filling trunk, which can be manufactured to suit the inlet pipe size. Multiple filling trunks can be manufactured into the silt tube. As a standard we will place a filling trunk per 10 linear metres of silt tubing. The location of the filling trunks is on top of the tubes to maximise the filling process, however trunks can be placed anywhere during manufacturing for specialist projects such as when silt tubes are used within a container such as a sealed roll on roll off skip bin.

As the sediment laden water is pumped into the silt tube, the geotextile traps the solid particles. The choice of material is important to ensure that the maximum amount of sediment is retained whilst taking into account the dewatering time required. After a period of filling the material will form a layer and blind the geotextile and stop water from flowing out.

At this point the silt tube filling should move onto another tube. As the pressure within the silt tube decreases the layer of silt cake will drop from the geotextile to the bottom of the silt tube ready for re-filling.

The process of filling the silt tubes is usually carried out through several filling cycles. Where more than one silt tube is required, it is advisable to use a manifold on the inlet pipework to allow for the silt tubes to be filled consecutively, which will allow the silt tubes time to dewater prior to re-filling.

MANUFACTURING

Murlac manufactures all of its silt tubes in the UK using a locking stitch. A lot of other silt tubes use a chain stitch which under enough pressure will fail and pull through. At the same time any fracture within the stitch which causes the chain to fail will result in the entire silt tube stitch to fail. Whereas a locking stitch if broken will only affect a few stitches either side of the fail. To reduce any failure of the stitch, all of our silt tubes are stitched using an industrial twin needle sewing machine, folded over and stitched again. This results in each seam or join having a total of 4 stitch runs.

We offer a floating silt tube installation service worldwide, providing trained operatives with construction and industry accreditation as standard.

 DELIVERY TIMESCALES

To ensure that murlac can service the needs of its customers whilst complying with legislation, we have a large stock of both hire and new silt curtains ready for immediate despatch using our own internal transport or Palletforce. Orders received before 4pm can be despatch the same day for next day delivery within the UK, 72 hours in the USA and within days worldwide. If required providing that the size you require is in stock, even if it is not in stock we will do our up-most to ensure that we deliver to our customers time-scales.