ISO 1179-2:2013 specifies dimensions, performance requirements and test procedures for heavy-duty (S series) and light-duty (L series) stud ends with ISO 228-1 threads and the elastomeric sealing (type E) that is used with them.
Heavy-duty (S series) stud ends with type E sealing in accordance with ISO 1179-2:2013 can be used at working pressures up to 63 MPa (630 bar). Light-duty (L series) stud ends with type E sealing in accordance with ISO 1179-2:2013 can be used at working pressures up to 25 MPa (250 bar). The permissible working pressure depends upon size, materials, design, working conditions, application, etc.