Use more mass to resist hoop stresses. Higher modulus materials will resist bending and deformation. Use a tandem seal design for pressure break down between two seals. Design for corrosion resistance Choose good materials, clearly identified by type and grade. Eliminate elastomers when possible.
Elastomers are the most corrosion sensitive part of the seal.
Design non stressed parts when ever possible Try not to weld any of the metal components. If it is necessary, monitor the temperature to prevent inter granular corrosion Control the temperature. Corrosion increases with temperature. Use non metallic materials for non metallic equipment. Watch out for galvanic corrosion when using dissimilar materials.