Regulators and tanks need to be specially cleaned and orings etc need to be oxygen compatible for very high O2 mixes. Really, all tanks should be O2 clean in case the shops are doing partial pressure blending (Pure O2 into the tank, then diluted with air... as opposed to premixing and banking nitrox).
But there are no equipment or cleaning differences between 50% and 100%. Anything over 40% is supposed to be O2 cleaned.