Important Information This information is important when dealing with any Hydraulic Bladder type Accumulators Only use Nitrogen gas for pre-charging, (Compressed air will heat up when the accumulator is working causing catastrophic affects.) Always mount Bladders accumulators vertically unless there is special reason not to. Never mount Bladder accumulators upside down. Specify pre-charge at time of ordering . Hydraulic Accumulators are subject to rigorous legislation, some of which is covered in this website, and is meant only as a guide, and may not necessarily be completely up to date. The hydraulic accumulators on this website are all for use with standard hydraulic oil. For information about accumulators for use with other types of oil, please fill in the enquiry form, and we will get back to you as soon as possible.