# O-Ring Gland Design Review Checklist > Source: https://netray.co/tools/o-ring-gland-design-review-checklist > Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems. > Section: Free Tools ## Short answer A structured design review for O-ring glands covering material selection, geometry, squeeze and stretch, surface finish, extrusion, assembly and inspection. ## Category quality ## Industry Fluid Power and Sealing ## Audience - Design engineer - Quality engineer - Manufacturing engineer ## Tool **Kind:** checklist **Groups:** #### Application and material **Items:** **Text:** Fluids, cleaning agents and gases in contact are listed with concentration and temperature **Critical:** true **Text:** Compound chosen from a compatibility chart for every fluid, not only the main one **Critical:** true **Text:** Minimum and maximum operating temperature fall inside the compound range with margin **Critical:** true Fluid swell and shrinkage after soak are accounted for in the gland design Compression set requirement stated with test time and temperature Special approvals identified: FDA, NSF, USP Class VI, ISO 10993 or similar Durometer chosen for pressure, extrusion gap and installation force #### Groove geometry **Items:** **Text:** O-ring size selected from a standard (AS568 or ISO 3601) with tolerances noted **Critical:** true **Text:** Squeeze calculated at minimum and maximum tolerance and inside the design window **Critical:** true **Text:** Gland fill calculated worst case including swell and thermal expansion **Critical:** true Installed stretch is at or below about 5 percent for piston and plug glands Groove corner radii are specified and not sharp Groove walls have a lead-in or chamfer for assembly where needed Face seal groove accounts for pressure direction (inside versus outside) #### Extrusion and backup **Items:** **Text:** Diametral clearance checked at maximum tolerance and operating temperature **Critical:** true **Text:** Extrusion gap checked against pressure and durometer using the supplier chart **Critical:** true Backup rings specified where pressure or clearance exceed the limit Pressure pulses and vacuum cycles considered, not only steady pressure Bore and piston concentricity and side loads are controlled #### Surfaces and assembly **Items:** **Text:** Surface finish specified: static grooves and dynamic surfaces use different Ra limits **Critical:** true **Text:** Sharp edges, burrs and thread crossings in the installation path removed or covered **Critical:** true Compatible lubricant specified for assembly and dynamic use Installation tool or sleeve specified for the O-ring passing over threads Cleanliness requirement stated for the groove and mating parts Mating surface hardness suits the seal material (especially for filled PTFE) #### Inspection and records **Items:** **Text:** O-ring part number, compound code and durometer appear on the drawing and BOM **Critical:** true Incoming inspection plan covers size, hardness and visual defects Lot traceability and cure date recorded; shelf life checked at receipt Certificate of conformance requested for critical sealing applications Test plan includes leak or pressure decay test at temperature extremes Design review outcomes and calculations stored with the part record **Scoring Note:** Every critical item should be closed before release. A single open critical item on a safety-related or high-pressure seal justifies a delay for further analysis. ## Content **Intro:** Most O-ring leaks trace back to a design or assembly oversight that a short review would have caught. This checklist walks through material, geometry, extrusion, surfaces and records so each sealing joint is reviewed the same way before release. **Sections:** #### How to use it **Body:** Run the checklist at design review for every new gland and whenever a fluid, temperature or supplier changes. Tick the items that are verified with calculations or drawings, and leave anything that is a guess unticked. Items marked critical should be closed before release. Export the completed list to PDF and file it with the design record so the next engineer can see what was checked. **Bullets:** - Do the squeeze, fill, stretch and clearance calculations first, then tick the boxes. - Bring the machinist or process engineer in for the surface finish items. - Review again after any compound or supplier change. #### Why these checks **Body:** The groups follow the order of failure causes seen in field returns: wrong or incompatible material, poor squeeze or overfilled groove, extrusion into the clearance gap, damage during installation, and no record of what compound was actually fitted. Compound compatibility and the tolerance stack come first because they cannot be corrected by assembly care. Installation items come last but account for a large share of leaks in practice. #### Reading the result **Body:** The checklist is a gate, not a score. If critical items remain open, finish the calculations or testing before release. Non-critical open items should become action items with an owner. Where the review reveals that a seal sits close to a limit, such as squeeze below 15 percent or fill above 85 percent, redesign the groove rather than relying on tight machining to hold it. #### Common mistakes **Body:** Reviewers often verify compatibility for the working fluid only, forgetting cleaning chemicals, test fluids and assembly lubricants that also contact the seal. Another gap is checking squeeze at nominal only. A third is accepting a drawing that gives a part number but no compound code, which lets a purchasing substitution slip through. Put the compound and durometer in the BOM description and the item master. **Cta:** If design reviews and supplier changes are tracked in separate systems, we can show how a private assistant flags seal-related changes in your ERP and asks for the checklist to be re-run. **Faq:** #### What is the most common cause of O-ring failure? **Answer:** Chemical incompatibility, extrusion, compression set and installation damage cover most failures. Installation damage from sharp edges and threads, and material not suited to a fluid or temperature, are especially common and are easy to catch in a design review. #### What surface finish is needed for an O-ring groove? **Answer:** A common guideline is about 32 microinch Ra (0.8 um) or finer for dynamic sealing surfaces and somewhat rougher, about 63 microinch Ra (1.6 um), for static groove faces. Gas and vacuum service usually need finer finishes. Check your supplier guidance. #### How often should the review be repeated? **Answer:** At each design release and any time the fluid, operating temperature, pressure, compound or supplier changes. Repeating it after field failures is also worthwhile. Keep the completed checklist with the part record so changes are visible. #### Do I need backup rings? **Answer:** Backup rings are used when pressure and clearance together exceed the extrusion limit for the O-ring durometer, which the supplier extrusion chart shows. High pressure, wide gaps, soft compounds and high temperature all push toward needing them. ## Search terms o-ring gland design checklist, o-ring groove design review, seal design review checklist, o-ring failure prevention checklist, o-ring installation checklist, o-ring groove surface finish, o-ring design guidelines, static seal design review --- Talk to an engineer: https://netray.co/contact?intent=erp_ai | Machine catalog: https://netray.co/agent/catalog.json