Record flange gaps at eight or more points before tightening and after each pass. The log works out the spread for each step and flags anything above your tolerance. A blank printable version is below. Values are for reference; confirm against the current edition of the governing standard. Send us your bolting list for a quote or call (281) 581-0176.
Related: Flange Tightening Pass Table · Flange Joint Tag · Flange Bolt-Up Record · All technical docs
Why measure gaps
- Even gaps show the flanges are closing parallel and the gasket is loading evenly (PCC-1 J-2).
- Measure at 8 or more evenly spaced points. Initial gaps should be within about 0.010 in. of each other.
- If keeping the gap even needs more than a 50% torque difference between bolts, take the joint apart and find out why.
- Gap checks are recommended for ring joints and for soft gaskets such as PTFE (F-8, F-9).
References: ASME PCC-1-2026, Guidelines for Pressure Boundary Bolted Flange Joint Assembly. Summaries are paraphrased; clause numbers refer to ASME PCC-1-2026 unless noted. Patriot Bolt manufactures bolting and does not perform bolting, training or joint assembly services.