PTFE (Teflon) seals provide ultimate chemical inertness for extreme conditions, handling acids, alkalis, and temperatures to 500°F in Fig. 2202 unions. Their low friction reduces makeup torque, aiding quick field connections. Reinforced with stainless steel for high-pressure integrity, PTFE suits nuclear and specialty chemical tie-ins to oil lines. Drawbacks include higher cost ($20+ ... https://globalsealstech.com/product/hammer-union-seal-2/