BS EN 58:2012 pdf download

BS EN 58:2012 pdf download.Bitumen and bituminous binders一Sampling bituminous binders.
81.5 Three-way valves (see Clause 6)
If samples of flowing material are to be taken from narrow pipes. e.g. on mixing plants, the installation of an easily accessible 3-way valve is convenieni The cock shall have an internal diameter appropnate to the size of the pipe, and shall be installed with the sampling outlet pointing downwards. The length of the pipe leading to the outlet shall be as short as possible. Figures 6 and 7 show an example of a three-way valve.
Necessity to draw off mateflal should be assessed (see 8,1.1 above).
If a representative sample is to be obtained, several spot samples shall be taken by opening the three-way valve at equal time intervals over the whole supply period.
This method is suitable for all luid materials In narrow pipes.
For well-mixed materials, a spot sample can be regarded as a repi’esentative sample, but for materials which are not well mixed, a composite sample shall be formed from at least three spot samples.
If a well-mixed material Is unloaded from a container vehicle, the sample shall be taken during the delivery of the second third of the material.
8.2 Sampling using submersible equipment
The procedures descnbed in 8.2 use permanently installed sampling devices and the depth from which the sample is taken is therefore fixed in advance without reference to the depth to which the tank may be filled at the bme of sampling. By the use of submersible equipment, samples can be taken from any depth,
8.2.1 W.Ightad sampling can. A weighted sampling can shall be used for sampling liquid materials and a typical example for high viscosity materials Is shown in Figures 8 and 9. For very fluid materials, a weighted sampling can of the type shown In Figure 10 may be used.
Clean the sampling can and close it with the bung: lower it by the suspension to the chosen depth in the tank. Take a layer sample by withdrawing the bung with a short jerk on the suspension. The sampling equipment shall then be held at a constant depth until it is full as indicated by a cessation in the formation of air bubbles.
NOTE The opening in the flask or can is smaU in comparison with its volume, so that there e no significant contamination of the sample by material from other layers during the subsequent slow withdrawal of the sampling appliance.
The method is suitable for sampling fluid material ‘in a storage tank, For well-mixed material and storage tanks of up to 50 m3 capacity, one spot sample, usually taken from the middle thid, can serve as a representative sample. For less well-mixed material and storage tanks greater than 50 m capacity, samples shall be taken from at least the top, middle and lower third of the material.
8.2.2 Surfac, sampling can. A surface sampling can shall be used to take lop surface samples of liquid material In tanks up to 50 m3 capacity. e.g. road tankers. This consists of a clean, open-top can, of suitable diameter, ii a holder. e.g. a laboratory stand. which also serves as a ballast weight The length of the holder shall permit the can to be lowered through the tank opening, and submerged below the surface of the material. Figures 11 and 12 show an example of a suitable holder.
Take a sample by fixing a clean can in the holder and submerging the can just below the surface of the test material.
8.2.3 Bottom-closing sampling tube (thief). A bottom-closing sampling tube consists of a tube, the upper end of which carries a handle linked to a shut-off disc at the lower end. For use in taking straight-through samples, the length of the sampling tube shall be at least equal to the depth of the material in the container. An example of a suitable arrangement is shown in Figure 13.