Material options for hammer union seals include nitrile (NBR), polyurethane, Viton (FKM), and specialized compounds. Nitrile provides economical sealing for petroleum-based fluids at moderate temperatures. Polyurethane offers excellent abrasion resistance for fracturing and cementing operations with proppant-laden fluids. Viton withstands high temperatures and aggressive chemicals. Ma... https://globalsealstech.com/product/hammer-union-seal-2/