How do I check the pre-charge pressure, and why does it matter?
Measure at the gas valve with a charging and testing unit, with the fluid side isolated and depressurised. The pre-charge sets how much volume a bladder accumulator actually takes up: too low and the usable stored volume drops; too high and the bladder hits the valve and wears out early. Check it after commissioning and at recurring intervals afterwards. PTS carries out testing and charging with its own technicians.
Can the bladder be replaced as a spare part?
On repairable designs, yes: the bladder is changed together with the seal kit and the shell stays in service. Replacement bladders and seal kits depend on size and manufacturer, so take the complete type designation from the accumulator nameplate. Sealed, non-repairable designs are exchanged as a unit.
What data do I need to select one?
Nominal volume, permissible working pressure, port and elastomer material. The volume follows the task: storing energy needs volume, while damping pulsations calls for a small accumulator close to the pump. Typical nominal volumes range from about 4 to 50 litres with pressure ratings up to 350 bar. Volume, port and permissible pressure are listed in each article technical data.
Diaphragm or bladder accumulator: which one when?
Diaphragm accumulators are compact and cover small volumes, but are usually not repairable. Bladder accumulators handle larger volumes and higher discharge rates and can be restored by replacing the bladder. For small damping duties the diaphragm type is enough; for energy storage and larger volumes, choose the bladder accumulator.