Specifies performance in respect of the maximum permitted heat loss, the materials, design and marking of jackets for cylinders to BS 699 and BS 1566.Cross References:BS 417:Part 2BS 476:Part 4BS 699BS 1566BS 1610BS 1763BS 3121BS 3198BS 3456:Part 2:Section 2.21BS 3533BS 4213BS 4422BS 5803:Part 1Replaces BS 5615:1978.