Anchor Bolt Anchor Bolt nawazz91 (Civil/Environmental) (OP) 29 Jun 15 05:41 Hello everyone, I wanna know the design of Oil tank with an example,probably an excel sheet if any and also the minimum spacing of anchor bolt in oil tank. Thanks in advance!!! RE: Anchor Bolt MOHAMMED89 (Mechanical) 29 Jun 15 11:19 Dear Nawazz91, For API 650 tanks, The maximum spacing of anchor bolt shall be 3m (Refer API 650, Clause 5.12.3).Allowable stresses for anchor bolts shall be in accordance with API 650, Table 5.21a and Table 5.21b for each load case. And an acceptable procedure for anchor chair design is given in AISI Steel Plate Engineering Data, Volume 2, Part 5, “Anchor Bolt Chairs.” (API 650, Clause 5.12.6). As per API there is minimum spacing requirement for anchor bolt. please note if the anchor is very close each other then it clash with the other shell nozzle, vertical shell joints etc. so you will force to provide combine RF pad etc.