The gasket is the enclosure
On a commissioning walkthrough last month, a new ten-bank elapid wall passed every spec on the drawings and failed at the gaskets. The fabricator had substituted a nitrile of nominally identical Shore rating; after three weeks under hot-room thermal cycling, compression set had opened the inner seam to 2.1 mm at the midline on three of ten doors. The drawings said EPDM for a reason. We now specify gasket material and durometer on the door elevation itself, not in the materials schedule, where substitutions are easier to slip past review.