UN R30 Supplement 24 (02 series) · UNECE Regulation No. 30 (ECE R30) — Uniform provisions concerning the approval of pneumatic tyres for motor vehicles and their trailers.
UN R30 — Supplement 24 to the 02 series of amendments
Supplement 23 → 24
- What changed
- In the “flat tyre running mode” procedures of Annex 7, paragraphs 3.2. and 4.2. now set an inflation pressure of 2.5 bar for conditioning.
- The temperature sensor position moves from paragraphs 3.2. and 4.2. to paragraphs 3.7. and 4.7. of Annex 7.
- The symbol for a tyre that is an EMT has a new drawing.
- Why
- In ISO, the dimension “0,33h” of the EMT symbol was judged wrong, and ISO experts agreed to remove it from ISO 16992:2018.
- Under ISO 16992:2018, the conditioning inflation value must not depend on speed.
- The temperature sensor position is a testing parameter, not a conditioning value.
Q1What changed5 changes
Inflation pressure for the flat tyre running mode tests (Annex 7, paras. 3.2. and 4.2.)
For run flat tyres, paragraph 3.2. now gives an inflation pressure of 2.5 bar. The paragraph also requires conditioning of the tyre-and-wheel assembly at 38 ºC ± 3 ºC for not less than three hours. For extended mobility tyres, paragraph 4.2. sets the same pressure and time at 25 ºC ± 3 ºC. Before, both paragraphs referred to the procedure in paragraphs 1.2. to 1.5. above. The test room temperatures do not change.
Temperature sensor position during the test (Annex 7, paras. 3.7. and 4.7.)
Paragraphs 3.7. and 4.7. now give the temperature sensor position: not less than 0.15 m and not more than 1.00 m from the tyre sidewall. Before, paragraphs 3.2. and 4.2. gave this requirement. The distance values do not change.
Drawing of the EMT symbol
The regulation gives a symbol for a tyre that is an EMT (extended mobility tyre). This supplement replaces the drawing of this symbol.
Q2Why it changed
- Proposed by
- Experts from the European Tyre and Rim Technical Organisation (ETRTO)
- Working party
- GRBP, 73rd session (January 2021)
Reasons
In an ISO working group, the dimension “0,33h” of the EMT symbol was judged wrong and an unnecessary over constraint. ISO experts agreed to remove this dimension from the EMT symbol of ISO 16992:2018. They also agreed to add the information that the two angles at the base are the same.
Sources (2)
“where the dimension "0,33h" was judged wrong and constituting an unnecessary over constraint.”
“ISO experts agreed to correct the standard ISO 16992:2018 EMT symbol by removing such dimension and introducing the information that the two angles at the base are the same.”
The proposal says that the amendment of the EMT symbol is important to allow symbol implementation. It is also important to prevent deviation from the requirement when the symbol is reproduced.
Source
“This amendment is important to allow symbol implementation and to ensure no deviation from the requirement in reproducing it.”
Under ISO 16992:2018, the inflation value for tyre conditioning must not depend on speed. The reason is that the “flat tyre running mode” test is at constant speed for all tyre speed categories.
Source
“as per ISO 16992:2018 this value shall not be speed dependant because the test performed for the "flat tyre running mode" is performed at constant speed irrespective of the tyre speed category.”
The amendment of the inflation value is intended to harmonise UN Regulation No. 30 with the ISO standard. The aim is also harmonisation with other UN Regulations that may refer to ISO 16992:2018.
Source
“the amendment is intended to ensure the harmonisation of this UN Regulation with the ISO standard and with other UN Regulations that may just refer to ISO 16992:2018 in setting their requirements.”
The temperature sensor position moves to paragraphs 3.7. and 4.7. of Annex 7 because it is a testing parameter and not a conditioning value.
Source
“the temperature sensor positioning requirements needs to be moved to paragraphs 3.7 and 4.7 in Annex 7 respectively for run flat and extended mobility tyres, because they address a testing parameter and not a conditioning value.”
Document trail
- 2020-11ProposalECE/TRANS/WP.29/GRBP/2021/4Proposal by ETRTO
- —Working party adoptsECE/TRANS/WP.29/GRBP/71Session report, para. 10
- 2021-04Sent to WP.29ECE/TRANS/WP.29/2021/75Text that GRBP sent to WP.29 and AC.1
- 2021-06WP.29 adoptsECE/TRANS/WP.29/1159Adopted at the 184th session (session report, para. 127)
- 2022-01-07In forceC.N.6.2022.TREATIES-XI.B.16.30UN depositary notification
Q3Who is affected
Vehicle manufacturer
- No direct action for this role.
Component supplier
- Be ready for conditioning at 2.5 bar in the flat tyre running mode tests (Annex 7, paras. 3.2. and 4.2.).
- If your tyre is an EMT, check that its EMT symbol matches the new drawing.
Technical service / Approval authority
- Inflate tyres to 2.5 bar for conditioning in the flat tyre running mode tests (Annex 7, paras. 3.2. and 4.2.).
- During the test, check that the temperature sensor is 0.15 m to 1.00 m from the tyre sidewall (Annex 7).
- During approval of an EMT, compare its EMT symbol with the new drawing.
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ⓘ This report gives advice only. It is not legal or type-approval advice.