Seal Washer Caps Viking Plastics’ line of seal washer caps provides unmatched protection, with ease of removal and recycling. This design offers the best seal with the most EPS credits. Viking co-developed the original seal washer cap in conjunction with a Tier 1 supplier. Download Brochure Request A Quote Contact Us Seal Washer Cap PART NUMBER DESCRIPTION CONNECTION SIZE BOX QTY 874-0409 Seal Washer Cap 3/8″ 2,000 874-0419 Seal Washer Cap 1/2″ 2,000 874-0429 Seal Washer Cap 3/4″ 2,000