Notes : 1 . All dimensions shown are nominal and subject to manufacturing tolerance . OD and bolt hole size and location are determined in accordance with ANSI standards . Drawing shown is an approximation only . 2 . The maximum pressure for gas applications should be calculated based on the applicable local and federal regulations . 3 . Back-up Rings are marked to meet the applicable standards . 4 . All Back-up Rings produced at AGRU Austria .