{"id":5288,"date":"2026-10-28T12:18:50","date_gmt":"2026-10-28T04:18:50","guid":{"rendered":"https:\/\/ptfesuppliers.com\/how-to-read-a-ptfe-gasket-drawing-before-ordering\/"},"modified":"2026-10-28T12:18:50","modified_gmt":"2026-10-28T04:18:50","slug":"how-to-read-a-ptfe-gasket-drawing-before-ordering","status":"publish","type":"post","link":"https:\/\/ptfesuppliers.com\/ru\/how-to-read-a-ptfe-gasket-drawing-before-ordering\/","title":{"rendered":"How to Read a PTFE Gasket Drawing Before Ordering"},"content":{"rendered":"

Short answer:<\/strong> Reading a PTFE gasket drawing before ordering means checking five things: the ID\/OD against your flange standard (not just the numbers), thickness with tolerance, whether the torque\/bolt-load note matches your bolting plan, surface finish callouts on sealing faces, and marking requirements. Two minutes with this checklist prevents the classic failure: a gasket that fits perfectly and still leaks because the flange was never what the drawing assumed.<\/p>\n

Drawings travel between engineering and purchasing intact \u2014 but assumptions don’t. This reading order catches the gaps.<\/p>\n

Check 1: Dimensions Against the Real Flange<\/h2>\n

Confirm ID\/OD against your actual flange standard (ANSI B16.21, DIN 2690, EN 12560, etc.) \u2014 not just plausibility. A DN80 gasket for DIN PN10 differs from DN80 for ANSI 150#. If the drawing says “per DIN,” verify which DIN. Bolt-hole gaskets: hole count and pitch circle get forgotten most often.<\/p>\n

Check 2: Thickness and Tolerance<\/h2>\n

Nominal thickness without tolerance is an invitation. Look for a band (\u00b15% or \u00b10.1 mm) and check the thickness is consistent with the flange condition discussed earlier \u2014 3 mm on a 0.2 mm gap flange is overkill that will creep.<\/p>\n

Check 3: Load and Torque Notes<\/h2>\n\n\n\n\n
Drawing note<\/th>\nWhat to confirm<\/th>\n<\/tr>\n
“Torque to XX Nm”<\/td>\nMatches your bolt spec and gasket thickness (thinner gaskets need controlled torque, not max torque)<\/td>\n<\/tr>\n
“Do not exceed XX MPa stress”<\/td>\nVirgin PTFE crushes above ~40\u201350 MPa gasket stress \u2014 note must exist for thin sections<\/td>\n<\/tr>\n<\/table>\n

Check 4: Surface and Edge Callouts<\/h2>\n

Sealing-face finish requirements (Ra values) and edge condition (chamfer, deburr) \u2014 these are where quotes diverge, because they drive process steps.<\/p>\n

Check 5: Marking and Revision<\/h2>\n

Revision number current, lot-marking requirement stated if you need traceability. Chunhuan produces gaskets to customer drawings with a DFM check before quoting \u2014 drawings with the five checks above quote fastest and cleanest.<\/p>\n

Frequently Asked Questions<\/h2>\n

What should I check first on a PTFE gasket drawing?<\/h3>\n

Dimensions against your actual flange standard (ANSI\/DIN\/EN) \u2014 including bolt-hole count and pitch circle, which are the most commonly forgotten features.<\/p>\n

Why does gasket thickness need a tolerance on the drawing?<\/h3>\n

Without a band, thickness is unverifiable and creep behavior is unpredictable. Look for \u00b15% or tighter, consistent with the flange gap.<\/p>\n

What gasket stress limit applies to virgin PTFE?<\/h3>\n

Roughly 40\u201350 MPa maximum sustained gasket stress before crushing risk \u2014 thin sections should carry an explicit stress\/torque limit note.<\/p>\n

How do surface finish callouts affect gasket quotes?<\/h3>\n

Ra requirements and edge treatment drive process steps; undefined finishes make quotes diverge and lead to rework at delivery.<\/p>\n