BS 7272-1-2008 pdf free download

BS 7272-1-2008 pdf free download.Writing and marking instruments Part 1: Specification for caps to reduce the risk of asphyxiation.
A2.1 Air supply, pulse free and with a flow rate of at least 25 I/mm within the pressure range of 4 kPa to 50 kPa.
A..2.2 Flow ,rqululor, capable of controlling the air flow with an accuracy of ±0.1 11mm.
A.2.3 Flow gauge, capable of measuring a flow rate of between 5 I/mm and 10 1/miri with an accuracy of ±0.2 I/win. A.2.4 Pressuie gauge, capable of mea.auring a pressure of at least 4.00 kPa to an accuracy of ±0.01 kPa.
A.2.5 Gauplinq and tubing, suitable for connecting equipment described above in accordance with Figure A. 1.
A.2.6 Elastomeric tubing, with an internal diameter of 80% to 85% of that of the circumscnbing circle of the cap to be tested, measured at its widest point; with a wall thickness of 0.75 mm ± 0.25 mm and Shore A hardness of 55 ± 10.
NOTE 1 The appa rat ris is iliust,nled in Figni A. 1.
NOTE 2 Tubing of dianieterx appropriate to the rap txx1 might be djfj7culI to obtain and U mighi be adt’antaqeous to 1wm4facture the tubing, as required, by a dip—moulding technique.
A.3 Procedure
A.3.1 Cut the elastomeric tubing (see A.2.6) into a length such that rIwn the cap is inserted there is a relaxed diameter of tubing at both ends of the cap when connected in the apparatus. Apply a soap solution or other suitable low viscosity lubricant to (he full internal area of the tubing. Insert the cap into approximately the centre of the tube length and ensure that as far as practicable the cap is parallel to the major axis of the tubing.
A.3.2 Using suitable connectors and tubing, connect the tubeleap assembly (see A.3.3) to the apparatus, in accordance with Figure A.!. Turn on the air supply and adjust the flow until the pressure gauge ifl(licates a liressure difference of 1 .33 kPa. Record the flow rate indicated on the flow gauge at this pressure.
A..3.3 Turn off the air supply, remove and reverse the tube/cap assembly and repeat A.3.2. Test the cap, giving the air flow results found in each direction.
A.3.4 Complete the test report (see 3.4).BS 7272-1-2008 pdf free download.