Heavier sealants can also be injected in the sealant injection fittings during an crisis each time a critical seal is needed. The spring supplies the initial load (a result of the reduced elasticity of Teflon), whilst the fluid strain delivers the load to force the lips about the sealing surfaces. https://stephenesfqb.wikiconversation.com/7214393/details_fiction_and_pipe_flanges_and_fittings