This part of ISO 6993 gives the requirements for non-end load-bearing fittings made of high-impact poly(vinyl chloride) (PVC-HI) intended to be used for the supply of gaseous fuels through buried pipelines having an operating temperature range of 0 °C up to and including °C and a maximum operating pressure of 200 mbar (20 kPa). It is applicable only to fittings manufactured from the high-impact PVC materials PVC-A, PVC-CPE and PVC-EPR and having joints with elastomeric sealing elements. The fittings are suitable for those gases not containing potentially damaging components in such concentrations as to impair the properties of the fitting material.