1、BRITISH STANDARD BS 7411:1991 Incorporating Amendment No. 1 Specification for Lever operated knapsack sprayersBS7411:1991 This British Standard, having been prepared under the directionof the Agricultural Machinery and Implements Standards Policy Committee, waspublished under the authorityof the Sta
2、ndards Boardand comes into effect on 30April1991 BSI 08-1999 The following BSI references relate to the work on this standard: Committee reference AGE/15 Draft for comment 89/78329 DC ISBN 0 580 19398 5 Committees responsible for this British Standard The preparation of this British Standard was ent
3、rusted by the Agricultural Machinery and Implements Standards Policy Committee (AGE/-) to Technical Committee AGE/15, upon which the following bodies were represented: AFRC Institute of Engineering Research Agricultural Engineers Association British Agrochemicals Association Ltd British Crop Protect
4、ion Council British Plastics Federation Health and Safety Executive Imperial College of Science and Technology Long Ashton Research Station Ministry of Agriculture, Fisheries and Food National Farmers Union Amendments issued since publication Amd. No. Date Comments 7431 December 1992 Indicated by a
5、sideline in the marginBS7411:1991 BSI 08-1999 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 Definition 1 3 General requirements 1 Appendix A Performance tests 3 Publication(s) referred to Inside back coverBS7411:1991 ii BSI 08-1999 Foreword This British Standard h
6、as been prepared under the direction of the Agricultural Machinery and Implements Standards Policy Committee, at the request of the Health and Safety Executive, and in cooperation with the International Pesticide Application Research Centre. The standard aims to reduce the severity of the need for p
7、rotective clothing through improvement in the design for safety in operation of lever operated knapsack sprayers. Performance criteria are specified which take account of the constraints of manufacture. A method of test is also given. A British Standard does not purport to include all the necessary
8、provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1 to 4
9、, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS7411:1991 BSI 08-1999 1 1 Scope This British Standard specifies requirements for the materi
10、als, finish and performance of lever operated knapsack sprayers to apply approved pesticides. NOTEThe title of the publications referred to in this standard is listed on the inside back cover. 2 Definition For the purposes of this British Standard the following definition applies. lever operated kna
11、psack sprayer an assembly consisting of a reservior or tank for carrying spray liquid, which is supported on the operators back by straps and which the operator pumps while spraying a left or right-hand lever is used to operate a diaphragm or piston pump, mounted usually inside (but, in some cases,
12、outside) the sprayer reservoir or tank. Air is retained in a small compression cylinder to force the liquid to the spray nozzle and to reduce pumping pulsations the tank is not under pressure but the compression cylinder is, so creating a residual pressure. The equipment is designed to enable a rang
13、e of nozzles to be fitted on a hand lance 3 General requirements 3.1 The sprayer shall not leak from any of its component parts under all working conditions. When tested in accordance withA.1 the leakage of spray liquid in a test period shall be within the following limits: a) a maximum of5mL from h
14、ose connections, control valves on the lance and similar sites; b) a maximum of6mL from tank, lid and ventilation valve. When tested in accordance withA.2 andA.3 the leakage shall not exceed5mL. 3.2 No part of the outer surfaces of the sprayer shall entrap spillages of liquid. The sprayer shall have
15、 a maximum surface retention of7mL of liquid when tested in accordance withA.5. 3.3 Spraying shall be controlled at the hand lance. A means of controlling the spray pressure shall be provided having an accuracy of 10%. If a pressure indicator is fitted it shall be upstream of the trigger valve. NOTE
16、The pressure gauge should be to a recognized standard (e.g.BS1780). 3.4 The maximum operating pressure at the nozzle shall be limited to4bar 1) . Any pressure adjustment device shall be external to the tank. A safety device to prevent the maximum pressure being exceeded in any part of the equipment
17、shall be fitted and designed to divert spray liquid to inside the tank. 3.5 The filler hole shall be not less than100mm across the smallest dimension. It shall have no sharp edges and shall be provided with a lid that can be securely fitted by the gloved hand of an operator. 3.6 Any air vent in the
18、lid or tank shall limit the escape of spray liquid to5mL either when tested in accordance withA.2, or if the sprayer is completely inverted. 3.7 A strainer, that is removable by gloved hands, shall be provided to fit into the tank opening. This shall have sufficient open surface area to allow liquid
19、 flow without splashing or spillage during the filling of the tank and for displaced air to escape. The strainer shall be capable of handling the entire sprayer tank contents without spillage when tested in accordance withA.4. 3.8 The tank shall have a minimum capacity of5L. 3.9 A device shall be fi
20、tted to indicate the volume of the contents of the sprayer tank, which shall be permanently marked at1L intervals to an accuracy of 5% and shall be clearly visible. 3.10 The total weight of the sprayer when fully loaded with water shall not exceed25kg. The shape of the sprayer/operator interface sha
21、ll be designed to avoid any discomfort. 3.11 The load bearing part of any strap shall be at least50mm wide. A load bearing waist strap shall also be provided. All straps and padding shall be non-absorbent. Straps shall be fitted with quick release catches and shall be adjustable whilst the sprayer i
22、s in the working position. When tested in accordance withA.9, there shall be no visible signs of damage to the straps or their support hangers at the completion of the test. 3.12 The sprayer shall remain upright and stable when stood on a level horizontal surface or lifted by the shoulder straps dur
23、ing normal fitting by the operator. There shall be facilities to park the lance and nozzle assembly when not spraying. 3.13 The pump handle shall be at least400mm long and shall be designed for right or left hand operation. A hand-grip shall be firmly fixed to the handle and shall have a minimum dia
24、meter (or minor axis) of25mm and a minimum length of100mm. 3.14 The minimum length of the lance from the front of the hand grip to the nozzle shall be500mm. 1) 1 bar = 10 5 Pa=10 5N/m 2 .BS7411:1991 2 BSI 08-1999 3.15 Hose connections shall be reusable. 3.16 All parts of the sprayer shall be made of
25、 materials which are unaffected by48h use with any approved pesticide. 3.17 Any residue left in the tank after system pump out shall not exceed50mL, with the sprayer set on a horizontal surface. 3.18 The manufacturer shall define an adequate cleaning routine after which no more than0.01% of the orig
26、inal spray liquid shall be retained. 3.19 Any filters fitted shall be capable of being cleaned and maintained or replaced. 3.20 The compression cylinder and any hose or pipework which operates under pressure shall show no signs of leakage pressure tested to1.5times the maximum rated pressure. 3.21 T
27、he sprayer shall show no loss in performance over the period of the test or develop any leaks when tested in accordance withA.6 andA.1. 3.22 The cut-off valve shall show no loss in performance over the period of the test or develop any leaks when tested in accordance withA.7 andA.1. 3.23 The sprayer
28、 tank shall show no loss in performance over the period of the test or develop any leaks when tested in accordance withA.8 andA.1.BS7411:1991 BSI 08-1999 3 Appendix A Performance tests A.1 Leakage test A.1.1 Fill the sprayer with water and a suitable tracer dye to the recommended fill mark capacity.
29、 With the trigger valves in the closed position, place the sprayer on a bench600mm from the floor and hang the hose and trigger/lance assembly from the sprayer. Leave the sprayer for15min and visually examine for leakage (see3.1) especially noting hose connections, nozzle trigger valve and the base
30、of the sprayer. Examine all entries to the tank for hoses, pumps, etc. A.1.2 Pump the sprayer to4bar and after15min do the following. a) Re-examine the same areas for leaks (seeA.1.1). b) Check that the trigger valve does not leak in either the open or closed position. c) Carry out a leakage test of
31、 the lance with the trigger valve open and the nozzle blanked off. A.2 Inversion leak test Invert the sprayer for5min and check that any leakage is less than that specified in3.1. This test is additional to the tilt test described inA.3. NOTEThe essential component of this test is to identify potent
32、ial areas of leakage that may contaminate the user or storage area. A.3 Tilt test Fill the sprayer with water and tilt at an angle of90 for5min on each of four orthogonal axes. Check that leakage from any part of the sprayer is not more then that specified in3.1. A.4 Strainer performance test Pour t
33、he entire tank contents from an unprofiled bucket at a rate of0.22l/s into the tank, through the strainer in the tank filler hole. A.5 Surface retention test With the sprayer standing on a firm horizontal surface, pour a tracer dye solution over the sprayer so as to wet all external surfaces. Wait f
34、or a period of2min with the sprayer standing on a clean and absorbent surface. Then swab the outer surfaces with an absorbent material. Determine by fluorimetry or spectrophotometry the quantity of dye absorbed by the swabs. At the same time, innoculate clean swabs with an accurately measured quanti
35、ty of the tracer which is then recovered to verify the stability and recovery of the tracer from the swabs. A sprayer shall pass the test if no more than7mL of tracer die solution are recovered from the surface of the sprayer. A.6 Durability test Securely support the sprayer by its straps on a simul
36、ated operator and operate the lever mechanically, avoiding the extreme top and bottom of each stroke. Pump water from the sprayer through a manifold with nozzles giving a minimum output of72L/h at3 bar at a maximum of35 strokes/min. The water sprayed into a separate tank shall siphon back into the s
37、prayer under test just before the pump completely empties the sprayer tank. Continue the test for a minimum of250h. A.7 Cut-off valve reliability test Fix the cut-off valve to a special test rig which ensures that the valve is operated no more than15times/min. Set the pressure of spray liquid at the
38、 nozzle to3 bar and operate the valve for50000 cycles. After this, inspect the valve for leaks and subject the valve to500 operations at4bar. Conduct this test using a standard spray nozzle which has an approximate discharge rate of0.750L/min at3.5bar. Conduct the test using water. Test the cut-off
39、valve for leakage at the maximum working pressure of4bar. A.8 Tank impact (drop test) Place a wooden platform,50mm thick by800mm square, on a level floor and surrounded by a metal cage to protect the examiner from possible injury. Fill the sprayer tank completely to its design capacity with water, a
40、nd allow it to drop from a height of600mm onto the platform. In six tests, the tank is held vertically before it is dropped; it is held horizontally on its back (as worn) in seven tests and with the base of the tank at an angle of10 for six tests on one side and six tests on the opposite side, makin
41、g a total of25 drops in all. A.9 Strap drop test Fill the sprayer tank completely to its design capacity with water and then hang it by its strap from a solid support comprising a horizontal bar of75mm outside diameter, simulating its carriage on the shoulder of the operator. Then lift it a distance
42、 of30cm and allow it to drop and hang by the strap25times.4 blankBS7411:1991 BSI 08-1999 Publication(s) referred to BS 1780, Specification for bourdon tube pressure and vacuum gauges. BS 7411:1991 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national
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