We offer two lines of hammer union seals, one from elastomer, another one from elastomer reinforced with anti-extrusion ring which is normally used for high pressure. The material mainly includes NBR, HNBR and Viton without/with brass or stainless steel anti-extrusion ring. It can fully meet the specific performance requirements of your demanding operating environment. https://globalsealstech.com/product/hammer-union-seal-2/