Pressure ratings for hammer union seals correspond to Figure designations established by industry standards ranging from Figure 100 (1,000 PSI working pressure) through Figure 3000 (30,000 PSI working pressure). Common drilling and completion applications use Figure 1502 (15,000 PSI) and Figure 2002 (20,000 PSI) connections. Seal designs must withstand rated working pressure plus safe... https://globalsealstech.com/product/hammer-union-seal-2/