Talk:Hydraulic accumulator

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At the end of the article is this sentence: "The gas precharge in an accumulator is set so that the separating bladder, diaphragm or piston does not reach or strike either end of the operating cylinder. The design precharge normally ensures that the moving parts do not foul the ends or block fluid passages." For a bladder style accumulator this is misleading. While it may be true for desired operational longevity, the bladder can and will contact the fluid port assembly if the fluid pressure is low enough. Check the various manufacturer's websites. When rebuilding the accumulator a small amount of pressure is put into the bladder to insure that the anti-extrusion ring and fluid port are seated correctly. It does this by expanding to fill the entire bladder and pushing down on the fluid port assembly. MMdelaIntec 20:08, 11 September 2007 (UTC)



correction: hooke's law is linear. the restorative force is directly proportional to excursion.

Contents

[edit] Pumped Reservoir Storage?

Doesn't pumped reservoir storage count as a hydraulic accumulator? (It would be basically a dead weight/raised weight accumulator, except that all of the dead weight is that of the fluid itself.) Lchiarav 05:25, 3 April 2006 (UTC)

No that is not. An accumulator should be able to store a considerable amount of energy. An oil tank does hardly store energy. Jeff 11:46, 25 March 2007 (UTC)

I think he is talking about Pumped-storage hydroelectricity. It stores energy, but in this article it is twice excluded by the definition: "a pressure storage reservoir in which a non-compressible hydraulic fluid is held under pressure by an external source", and again by one of the purposes (presenting a more even load to the hydraulic pumps). Pumped storage uses a vast open mostly-natural reservoir, with no artifice pushing down on it. The pressures could be quite high (200ft drop), but the water is never used for a hydraulic power system, only to continuously run turbines for electrical generators.

Note, the "hydraulic engine house" example in the article also violates one part of the definition by not using any pressure on top of the water, but: the tank is man-made, and the hydraulic pressure is used for intermittent direct work, not a generating plant. Whiner01 04:37, 23 October 2007 (UTC)

[edit] bladder-type hydraulic accumulator

See also Jean Mercier. Scottcmu 16:21, 31 October 2006

[edit] spring type???

I see that a spring type hydraulic accumulator is mentioned. I wonder whether this type of accumulator was ever used. Anyway, I do not know one application. Reason is that the amount of energy that can be stored in a spring driven hydraulic accumulator is negligible. So it is better to delete this item. Jeff 11:46, 25 March 2007 (UTC)

[edit] Removed section

I removed the following section as it does not really belong in an encyclopedia. It looks to have come from a user manual or product blurb. It obviously does not apply to all types of accumulator, yet it doen't readily fit with any that are described.

I've left it here for someone more knowledgeable to process appropriately.

EdJogg (talk) 11:58, 2 April 2008 (UTC)

<<<START>>>

Guide to Accumulator bladder storage and shelf life
  • Bladders are guaranteed for 24 months from date of despatch.
  • Stored under ideal conditions they have an expected shelf life of 8 to 10 years.

Ideal Conditions:-

  1. Stored in a stress free condition either due to natural shape or by partially inflating to natural size with nitrogen gas.
  2. At temperatures 0 degrees C plus or minus 5 degrees C
  3. In a dark sealed box and away from direct sunlight, heat or rotational electrical equipment.

For other conditions see A and B.

A.

Where ideal conditions of storage cannot be met, they have an expected shelf life of 5 to 6 years if they are stored under the following conditions:-

  1. Stored in a stress free condition either due to natural shape or by partially inflating to natural size with compressed air or nitrogen gas.
  2. At temperatures up to 25 degrees C
  3. stored in darkness either in a dark room or covered with clean opaque or black polythene away from direct sunlight, heat or rotational electrical equipment.
B.

Where ideal conditions of storage cannot be met they have an expected shelf life of 2 to 3 years if they are stored under ideal conditions.

  1. Stored in stress free condition by inflating with compressed air or nitrogen gas, so that they lay flat with flat without bending or folding which would promote sharp breaks or cracks in the rubber surface.
    Note- Do not stack the bladders
  2. At temperatures up to 25 degrees C.
  3. stored in dark room on a shelf covered with clean opaque or black polythene away from direct sunlight, heat or rotational electrical equipment.
Inspection before use
  1. Inflate to not more than 1.5 times natural diameter.
  2. Visual examination of seams.
  3. Visual examination of surface for crazing.
  4. Immersion test in water.
Note 1.

Rubber products, not stored properly, will be subjected to attack from ozone, heat and UV light. Cracking will develop within one year.

<<<END>>>