Two tests with similar names and different purposes. A water flow test asks what the supply can actually deliver: open something, measure the pressure before and during, and compare with the last time. Hose testing asks whether the hose and the equipment attached to it are fit to be used: pressure it, look at it, and confirm every part is present. One is about the building's water, the other is about the kit somebody picks up in an emergency, and mixing them up is how a building ends up with a full folder and no idea what its supply does.
What a flow test proves, and what it does not
It proves the relationship between pressure and flow at the point tested on the day tested. Static pressure with nothing moving, residual pressure with a known flow, and from those two the supply's capacity can be estimated. What it does not prove is that the supply will be the same next month: municipal pressure varies with demand, tanks are refilled, pumps drift. That is exactly why the federal requirement for sprinkler systems is an annual main drain flow test rather than a single commissioning figure, and why the comparison between years is the real output.
Hose testing, and the annual inspection behind it
Standpipe hose is inspected at least annually and after each use, to assure that all of the equipment and hose are in place, available for use and in serviceable condition. That is an equipment check: is the hose there, is the nozzle there, is the rack usable, has anything been taken. Pressure testing hose on a service cycle is a separate exercise under the adopted standard, and where a system or any portion is found not to be serviceable the federal rule is that it is put back into serviceable condition promptly.
Acceptance testing is a different number again
When Class II and Class III standpipe piping is installed, the acceptance test is hydrostatic: at least two hours at not less than 200 psi, or at least 50 psi above normal pressure where normal exceeds 150 psi. That figure belongs to commissioning rather than to the annual round, and it is worth keeping on the building's record anyway, because an inspector arriving years later has no other way of knowing what the system was proven at.
What to write down, either way
For a flow test: the date, the point tested, static, residual, the flow used and the last comparable figures. For a hose inspection: the date, each cabinet or rack, what was present and what was missing, and whether the system has been used since the last check. In both cases a pass mark alone is worth almost nothing a year later; the numbers and the itemised findings are what turn this year's test into next year's evidence.
Questions people ask about water flow test
Is a main drain test the same as a water flow test?
It is one kind of it. The main drain test uses the drain's known orifice to produce a flow at the riser and reads static and residual against it. A full hydrant flow test uses a hydrant and pitot readings to characterise the supply more thoroughly and is normally done for design rather than for the annual round.
How often should hose be inspected?
The federal floor is at least annually and after each use. Adopted standards add pressure-service testing on a longer cycle, typically several years, and require replacement rather than repair for hose that fails it.
What pressure is standpipe piping tested at when it goes in?
At least two hours at not less than 200 psi, or at least 50 psi over normal pressure where normal is above 150 psi, for Class II and Class III systems installed after 1 January 1981. That is an acceptance test, not a recurring one.
Who can do a flow test?
Someone competent to do it without damaging the system or flooding the property, which in practice means the fire protection contractor and, for hydrant flows, often the water utility or the fire department. The risk in a badly run flow test is not a bad reading, it is water where it should not be.
What if this is the first test and there is nothing to compare with?
Write the numbers down and say so. A first test establishes the baseline that makes every later one useful, and recording it as a baseline rather than as a pass is the honest and more useful framing.