In case of pipes on a pipe rack, when flanges or flanged valves are required on two adjacent lines, it is necessary to stagger flanges as shown in following diagram, to reduce required space on pipe rack.
Minimum spacing between adjacent lines shall be decided based on O.D. of bigger size flange, O.D. of the smaller pipe, individual insulation thickness and additional 25 mm clearance.
Even if no flange is appearing on pipe in a pipe rack, spacing should be based on considering a flange in pipe.
Typical formula for spacing is as follows :
Spacing = Half OD of a flange which is larger between two pipes + Half OD of other pipe + insulation thickness of both pipes + 25 mm (or 1 Inch).
Spacing between pipes on a pipe rack.Larger spacing may be required if pipes have clamped supports. In such case, for economic reasons, clamped pipe supports at an angle of 45 degrees should be used.