Why fire systems don't use a hydropneumatic tank?
Why fire systems don't use a hydropneumatic tank?
(OP)
According to the large amount of information on the web about hydropneumatic tanks and their large use in industrial hydraulic applications I got to wonder, why is it that fire systems (for sprinklers and/or hoses) do not use them? Is there a dissadvantage if one would use them?





RE: Why fire systems don't use a hydropneumatic tank?
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Why fire systems don't use a hydropneumatic tank?
I have read just enough NFPA documents to realize that some non-obvious reasoning is behind many of the requirements. ... and not enough to comment on why an accumulator is atypical.
Mike Halloran
Pembroke Pines, FL, USA
RE: Why fire systems don't use a hydropneumatic tank?
RE: Why fire systems don't use a hydropneumatic tank?
So if there are advantages in using such tanks, why aren't they common in fire systems?
RE: Why fire systems don't use a hydropneumatic tank?
lilliput1: in a fire system, what would cause the design pressure to exceed its design, maybe a bit of thermal expansion but then the system would or should be designed for this likelihood. For interest, a sprinkler / hose reel system is maintained at a higher standby pressure than the operating system anyway - jacking pumps are set to cut in / out above the sprinkler hose reel operating pressure.
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Why fire systems don't use a hydropneumatic tank?
RE: Why fire systems don't use a hydropneumatic tank?
In some systems you will find accumulators, but I'm still not sure what advantages you think they bring to the party.
Accumulators are common and well used on re-circulating systems where the contents don't leak out and are not intended to leak out and where expansion and contraction occur due to thermal expansion of the fluid.
Fire systems are different.
Sprinklers are often just connected to the mains water and float on the mains water pressure - no need for an accumulator. Ditto fire systems in buildings and other places connected to mains water.
The thermal expansion and contraction are very low.
Standalone systems such as plants and refineries etc with fire water ponds and pumps tend to have large systems which in essence act as the accumulator. Whilst water is almost incompressible it's not a solid and neither is the pipes (often buried PE) so some expansion is possible when the jockey pump kicks in.
Large systems often end up with small leaks or are used for washing things down or supplying test water etc. In either case an accumulator does not really add anything to the party.
The systems are setup so that if either the fire alarm is pressed the main pumps start or if you just turn on a hose or hydrant the pressure falls until the jockey pump can't cope and then the main pumps swing into life. The volume available in an accumaultor is not enough to make any difference in these circumstances.
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RE: Why fire systems don't use a hydropneumatic tank?
RE: Why fire systems don't use a hydropneumatic tank?