A hydraulic accumulator can allow a system to increase its cost-effectiveness, offer continuous, dependable operation and can store emergency power should there be an electrical failure…
Hydraulic systems often include a hydraulic accumulator. They have two functions: one, to store energy and two, to smooth out pulsations. If your hydraulic system includes an accumulator it will also be able to operate with a smaller pump. This is because the accumulator is able to store energy from the pump when the demand is lower. The built-up energy is ready for use the moment it is needed and can be released at a rate much higher than that that would be released with the pump on its own.
A hydraulic accumulator can also double-up as surge or pulsation absorbers, just like an air dome used on pulsating piston or rotary pumps. Accumulators cushion the hydraulic hammer, which helps to reduce shocks caused by the quick movement or sudden starting and stopping of power cylinders in a hydraulic circuit.
There are four main types of hydraulic accumulator: the weight-loaded piston-type accumulator, the diaphragm accumulator (also known as a ‘bladder’), spring-type accumulator and the hydro-pneumatic piston type accumulator. The weight-loaded piston-type accumulator was the first to be used, however it is much larger and heavier than a modern piston or bladder accumulator. This version of the piston accumulator and the spring-type are seldom used nowadays, but the hydro-pneumatic accumulators are the kind that are most commonly found in modern hydraulic systems.
What is a hydraulic accumulator used for?
Storing energy – Hydropneumatic accumulators use a gas as well as hydraulic fluid, which can be compressed into smaller volumes at higher pressures. Potential energy is stored in the compressed gas and will be released once it is required. This kind of energy is similar to that of a raised pile driver transferring its huge energy upon the pile. With a piston accumulator, the energy in the compressed gas exerts pressure against the piston separating the gas and hydraulic fluid. This forces the fluid from the cylinder into the system and consequently to the location where it is required.
Pulsation absorption – In a hydraulic system, pumps create the power that needs to be used or stored. The majority of pumps distribute this power in a pulsating flow. As the piston pump is usually used thanks to its ability to operate under high pressure, the pulsations can be damaging to a system working under high pressure. An accumulator cushions the system against the pressure variations.
Shock cushioning – There are a number of hydraulic applications where the driven member of the system makes a sudden stop, which produces a pressure wave that moves back through the system. During operation, this means that the peak pressures that appear are much greater than the usual working pressures. This creates unpleasant noise or in severe circumstances, system failure. The accumulators gas cushion can help to reduce the shock.
Maintaining pressure – When the liquid in a hydraulic system is exposed to rising and falling temperatures, it causes pressure changes. There could also be drops in pressure due to a hydraulic fluid leak. By giving or taking a little bit of the hydraulic fluid, a hydraulic accumulator compensates for pressure changes.
Fluid dispensing – Accumulators are able to distribute small volumes of hydraulic fluid, including as soon as they are required.
A couple of examples of some of the projects we’ve undertaken included some Parker bladder accumulators that were for a UK-based electro-mechanical equipment exporter, and then on the right, these accumulators that were despatched to a company who specialise in the services and repair of plant and hydraulics. They were 10 litre nitrile bladder accumulators with elastomeric seals. They have a maximum pressure of 345 bar. We have also dispatched a .75 litre accumulator with a maximum pressure of 350 bar, pressure on port line: 10-70 bar, maximum back pressure on tank line: 3 bar, minimum pressure: 10 bar and oil capacity of 12 litres/minute.
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Thanks to our seemingly unrivalled access to a vast range of hydraulic manufacturers from around the world, and our innovative approach to hydraulic problem solving, Hydraulics Online are THE hydraulic supplier that a rapidly increasing number of customers turn to for all their equipment and systems design needs.
Large and small alike, our customers frequently rationalise their existing hydraulic supplier base, knowing that the team here can be relied upon to deliver trusted advice and solutions… backed up by reliable deliveries of equipment from both well-known and niche manufacturers. Hydraulic equipment that, in the nicest possible sense, they can then just “fit and forget”.
Not only that, but our team are fast gaining a reputation for loving a challenge. Straight forward and easy can be boring, right? We like to be kept on our toes. We are regularly tasked with sourcing seemingly obsolete or discontinued components and haven’t been beaten yet. Often working to the tightest of budgets and delivering “yesterday”, if an original product isn’t available, or lead times are unworkable, we can offer a direct equivalent or re-manufactured unit.
We like to say that…
If it’s hydraulic we can design it, supply it, solve it or repair it!
That includes: hydraulic pumps, motors, power packs and units, cylinders and rams, valves, filters and filtration systems, accumulators, and coolers and accessories for any kind of application in any kind of market – even ATEX rated equipment .
As an ISO 9001 accredited business, we don’t just “sell” hydraulics however… unless that’s all you want us to do. We aim to make it our business to understand your business, so that we can be certain we can give you the best advice possible and recommend products that really are “fit for purpose”.
Technical advice and assistance was first class and we would not hesitate in contacting you in the future to satisfy our requirements.
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It goes without saying that we love all things hydraulic. And, keen as we are to spread the joy and understanding of hydraulic engineering, and believing that prevention is always better than cure we have produced what we hope you will agree is a useful reference section.
We add to this on a regular basis but, if you click on the links here you can find:
- an introduction to hydraulics and some of the hydraulic components that make up a hydraulic system
- information on Pascal’s Law;
- a brief biography on Joseph Bramah, best known for having invented the hydraulic press and who along with William George Armstrong, can be considered one of the two fathers of hydraulic engineering.
- a ”Jargon Buster” and Hydraulic Symbols Chart to help you get your bearings;
- an overview of the ATEX Directive and Regulations .
And finally, based firmly on the belief that prevention is better than cure we have some hints, tips and trouble-shooting guidance for you.
We have never tried, or even thought about trying, to measure the scale of our product offering – the number is, however, unquestionably huge! Our online catalogue showcases a very small selection of the products that we supply – we couldn’t possibly squeeze everything that we do in here!
A hydraulic accumulator acts as an energy storage device within a hydraulic system – a pressure storage reservoir in which a non-compressible hydraulic fluid is held under pressure by an external source.
Bladder accumulators provide a means of regulating the performance of a hydraulic system. They are suitable for storing energy under pressure, absorbing hydraulic shocks, and dampening pump pulsation and flow fluctuations. Bladder accumulators provide excellent gas and fluid separation ensuring dependable performance, maximum efficiency, and long service life.
Parker’s range of bladder accumulators offer:
- operating pressures to 6600 PSI;
- ten different capacities from 10 cu in to 15 gallons;
- ASME certification standard, 1 gallon and above;
- operating pressures to 6600 PSI
- water/chemical service available, with stainless steel ports
- five bladder compounds to suit a variety of fluids & temperatures.
The nine Parker bladder accumulators pictured here were for a UK-based electro-mechanical equipment exporter. So if you’re looking for a hydraulic accumulator, whether it’s a: bladder accumulator, diaphragm accumulator or piston accumulator, then you’ve come to the right place!