Heldon’s standard copper fittings are substantially thicker on average than other fittings presently on the market, as they are manufactured to exceed ASME Standard B 16.22-1989. Consequently they also have a higher pressure rating. Burst tests further indicate that Heldon copper fittings are more than 10% stronger than other fittings on the local market. A large range of refrigeration fittings are available up to 4-1/8â€