BRITISH STANDARD AUTOMOBILE SERIES BS AU 50 3 8 1985 Incorporating Amendment No 1 Tyres and wheels — Part 3 Valves — Section 8 Code of practice for the selection and care of tyre inflation valves for[.]
BRITISH STANDARD AUTOMOBILE SERIES BS AU 50-3.8:1985 Incorporating Amendment No Tyres and wheels — Part 3: Valves — Section 8: Code of practice for the selection and care of tyre inflation valves for commercial vehicles UDC 629.113.012.551 – 396.2 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BS AU 50-3.8:1985 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Automobile Standards Committee (AUE/-) to Technical Committee AUE/4 upon which the following bodies were represented: Agricultural Engineers’ Association British Industrial Truck Association British Pressure Gauge Manufacturers’ Association British Rubber Manufacturers’ Association Bus and Coach Council Department of Transport London Transport Executive Ministry of Defence Motor Cycle Association of Great Britain Motor Industry Research Association Retread Manufacturers’ Association Road Haulage Association Ltd Society of Motor Manufacturers and Traders Limited This British Standard, having been prepared under the direction of the Automobile Standards Committee, was published under the authority of the Board of BSI and comes into effect on 28 February 1985 © BSI 06-2001 The following BSI references relate to the work on this standard: Committee reference AUE/4 Draft for comment 84/71549 DC ISBN 580 14327 Amendments issued since publication Amd No Date of issue 11053 June 2001 Comments Indicated by a sideline BS AU 50-3.8:1985 Contents Page Committees responsible Inside front cover Foreword ii 8.1 Scope 8.2 Valve selection by vehicle manufacturer 8.3 Types of valves 8.4 Valve fitting checks 8.5 Valve accessibility 8.6 In-service valve checks 8.7 Check list for care of inflation valves for commercial vehicles © BSI 06-2001 i BS AU 50-3.8:1985 Foreword This section of BS AU 50-3 has been prepared under the direction of the Automobile Standards Committee This code of practice gives guidance to vehicle manufacturers on the initial steps to be taken in selecting valves for commercial vehicles wheels Recommendations are also given on the care of valves, which if followed would lead to improved road safety The data in this code of practice are based on the information provided by the Society of Motor Manufacturers and Traders Ltd Tyre, wheel, rim and valve requirements are given in the following parts and sections of BS AU 50: Tyres and wheels: — Part 1: Tyres; — Section 0: General; — Section 1: Car tyres; — Section 2: Commercial vehicle tyres; — Section 3: Off-the-road tyres; — Section 4: Agricultural vehicle tyres; — Section 5: Industrial vehicle tyres; — Section 6: Motor cycle and scooter tyres; — Part 2: Wheels and rims; — Section 0: General (including terms and definitions, and construction and workmanship); Section 1: Rim profiles and dimensions (including openings for valves); Section 2: Wheel naves and hub centres; Section 3: Wheel and hub studs and nuts, and bolts 1) ; Section 4: Supplementary data for future developments 1) ; Section 5: Road wheels manufactured wholly or partly of light alloy for passenger cars; Section 6: Specification for road wheels manufactured wholly or partly of light alloy for mopeds and motor cycles; Section 7: Code of practice for the selection and care of wheels for commercial vehicles1) ; Section 8: Code of practice for the selection and care of wheels for passenger cars (including caravans and light trailers)1) ; Part 3: Valves; Section 1: Valve dimensions; Section 2: Tyre valve threads 5V1, 5V2, 6V1 and 8V1; Section 3: Tyre valve threads 9V1, 10V2, 12V1 and 13V1; Section 4: Tyre valve threads 8V2, 10V1, 11V1, 13V2, 15V1, 16V1, 17V1, 17V2, 17V3, 19V1 and 20V1; Section 5: Dimensions for ISO core chamber No for tyre inflation valves; Section 6: Dimensions for ISO core chamber No for tyre inflation valves; Section 7: Code of practice for the selection and care of tyre inflation valves for passenger cars (including caravans and light trailers); Section 8: Code of practice for the selection and care of tyre inflation valves for commercial vehicles — — — — — — — — — — — — — — — — — 1) ii In preparation © BSI 06-2001 BS AU 50-3.8:1985 A British Standard does not purport to include all the necessary 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 to iv, pages to and a back cover The BSI copyright notice displayed in this document indicates when the document was last issued Sidelining in this document indicates the most recent changes by amendment © BSI 06-2001 iii iv blank BS AU 50-3.8:1985 8.1 Scope This section of BS AU 50-3 gives recommendations for vehicle manufacturers on the initial steps to be taken in selecting valves for commercial vehicle wheels and recommendations for the care of valves for the user 8.2 Valve selection by vehicle manufacturer When selecting a valve for a wheel and tyre assembly it is important to ensure that the correct choice is made Basic factors which influence this choice are: a) type of tyre (tube type or tubeless); b) inflation pressure of the tyre; c) type of wheel The basic choice is between tube type and tubeless tyres This would generally be decided by the vehicle design and performance requirements and the valve type is therefore predetermined 8.3 Types of valves 8.3.1 General Valves are available in the following two basic types: a) tubeless type valves, which can be either of the rubber snap-in or metal clamp-in types (see 8.3.2 ); b) tube type valves, which can be either one piece or two piece valves (see 8.3.3 ) 8.3.2 Tubeless valves 8.3.2.1 Rubber snap-in valves Rubber snap-in valves are available in several different lengths and sizes and care should be exercised in selecting the correct size to suit the rim hole, and the most suitable length for ease of access so as not to be damaged in service The valve stem is threaded internally and externally for fitment of the valve core and valve sealing cap respectively It is essential that special care should be taken when fitting rubber snap-in valves First the rim hole should be inspected to ensure it is in good condition and free from burrs and sharp edges which can damage the rubber body of the valve Then the rubber body of the valve should be lubricated with an approved lubricant for ease of fitting and inserted into the rim hole using a special valve insertion tool To ensure that the valve is correctly located, it is essential that the moulded fitting line on the rubber valve body passes completely through the rim valve hole NOTE This type of valve is suitable for tyre inflation pressures up to a maximum of 475 kPa (4.7 bar or 69 psi) 8.3.2.2 Clamp-in valves Metal clamp-in valves are available in a variety of sizes It should always be ensured that the correct valve is fitted for the rim hole size and application Clamp-in valves for tubeless truck tyres are clamped into the rim and an airtight seal is achieved by means of a hexagonal nut and rubber grommet During fitting it should be ensured that the valve is correctly located relative to the wheel components to ensure ease of access for pressure checking and adjustment 8.3.3 Tube valves 8.3.3.1 One piece valves These are rubber based or rubber covered straight stem valves which are vulcanized to the inner tube and bent when required to given angles and dimensions 8.3.3.2 Two piece valves These consist of a rubber “spud” and a pre-bent stem (dimensions according to requirement) which is attached to the “spud” when required The two piece valve is sometimes referred to as “universal” It is essential that care is exercised to ensure correct location of the valve in the flap (where fitted) and in the rim aperture to prevent unnecessary strain on the valve in use © BSI 06-2001 BS AU 50-3.8:1985 If the valve is of the universal screw-on type it is essential that it should be fitted with the correct rubber washer in good condition and sufficiently tightened to form an airtight seal by continuing to tighten down the stem a further two turns after the stem’s metal washer has touched the rubber washer The valve should be aligned by additional tightening 8.4 Valve fitting checks Whenever a tubeless tyre or a tyre and tube assembly is inflated or the inflation pressure is checked and/or adjusted it is essential that a final check should be made that the valve has correctly sealed Leaking valve cores should be replaced It should not be attempted to cure a leaking valve by extra tightening as this may damage the core seal It should be ensured that the valve hole in the rim is in good condition and is free from burrs which could damage the valve and cause deflation of the tyre A valve cap of the type which acts as an additional air seal and which protects the core from dirt, dust and water should always be fitted 8.5 Valve accessibility Where access to the valve for inflation or pressure checking purposes is difficult, a valve extension may be used If extensions are required to assist accessibility for inflation, deflation and pressure checking, it is important that they should be securely attached to the valve, preferably by light wrench tightening Flexible extensions should be suitably supported It should be ensured that the extension is of the correct length and style to suit the required application The sealing extension should be fitted with a valve cap, unless the extension precludes this 8.6 In-service valve checks New rubber snap-in valves and the rubber components of metal clamp-in valves should always be fitted when fitting new replacement tyres Rubber covered valves should be examined regularly for splits and cuts Damaged valves should be replaced immediately All valves should be examined regularly for damaged cap threads and/or distorted valve mouth where the cap is fitted The internal valve core threads should also be examined for cleanliness If the valve mouth is distorted the valve should be replaced The metal parts of tubeless or tube valves can become damaged or distorted during their service life Distortions may have weakened the valve to a point of possible fracture and in such cases the valve should be replaced immediately It should be ensured that the radiused valve mouth which contacts the cap sealing washer is smooth and without nicks and burrs which may scuff and tear the cap seal Damaged cap threads, internal core threads and valve mouths should be repaired with an appropriate and recommended repair tool 8.7 Check list for care of inflation valves for commercial vehicles The following check list should be used for care of inflation valves for commercial vehicles a) Do ensure the valve and valve fitting is the correct size and type for the wheels and usage, e.g it is essential that clamp-in valves are used for inflation pressures above 475 kPa (4.7 bar or 69 psi) b) Do regularly check on valve cores for leakage Replace damaged or leaking cores c) Do ensure that valve caps are always fitted and replaced after removal Sealing type valve caps are preferred Do not assume that “any-old” valve or valve fitting is suitable Do not attempt to cure leaking valve core by over-tightening Damage to core seat can easily result Do not leave valve caps on the ground when servicing They can become damaged or lost © BSI 06-2001 BS AU 50-3.8:1985 d) Do ensure that the valve holes in tubeless rims are Do not attempt to remove pits, rust and burrs in good condition and the surrounding area free from by grinding or heavy filing The holes may rust, pits and burrs Seek advice if in doubt become irregular in shape and affect valve sealing Do not attempt fitment of a snap-in type e) Do ensure that after fitting a rubber covered snap-in tubeless valve, the indicating ring around the tubeless valve without the correct mounting body is fully visible on the outside of the rim This is tool Do not use grease or dirty lubricant an indication of correct fitment Use an approved lubricant f) Do ensure that clamp-in type valves are correctly Do not use excessive force to tighten clamp-in positioned and securely fitted valve securing nuts g) Do examine regularly the valve’s rubber fitments Do not attempt to fill cracks or splits with or rubber cover for cracks or splits and examine the paint, or attempt to repair valve distortions, metal portions of the valve for distortion and the nor attempt clearing or cleaning of thread threads for damage Ensure that valve mouth is or valve mouth without the appropriate and round, smooth and without nicks or burrs which recommended repair tool would hinder the sealing quality of the cap If in doubt change the valve or appropriate fitment immediately h) Do ensure that new snap-in valves or clamp-in Do not assume that tyre valves will last valve rubber fittings are fitted when replacing forever tubeless tyres i) Do ensure that if valve extensions are used they are Do not use an extension if inflation and the correct type and length for the application and pressure checking can be achieved without it they are securely tightened on to the valve Flexible extensions should be suitably supported j) Do ensure that valves of the universal screw-on Do not overtighten universal screw-on type type are fitted with the correct rubber washer and valves or omit rubber washers nor align valves sufficiently tightened to form a seal, by continuing to by unscrewing stem screw down the stem a further two complete turns after the stem’s metal washer has touched the rubber washer Align valve stem by additional tightening © BSI 06-2001 BS AU 50-3.8:1985 BSI — British Standards Institution BSI is the independent national body responsible for preparing British Standards It presents the UK view on standards in Europe and at the international level It is incorporated by Royal Charter Revisions British 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