SHUTOFF HEAD POINT
SHUTOFF HEAD POINT
(OP)
I NEED TO TEST A PUMP AT THE SHUT OFF HEAD POINT, TO CHECK IF I WILL GET THE SAME VALUE SHOWN AT THE CURVE.
From your experience , Do I have to close the throttling valve totally before running the pump OR to close the valve gradually during running the pump till we reach the shutoff head ?
From your experience , Do I have to close the throttling valve totally before running the pump OR to close the valve gradually during running the pump till we reach the shutoff head ?





RE: SHUTOFF HEAD POINT
Don't forget to account for suction pressure when you do your calcs, and don't run it this way for too long.
RE: SHUTOFF HEAD POINT
If you do want to test I suggest setting the valve partially closed and starting the pump, and then closing the valve the rest of the way. Take data quickly, most pumps will not run this way long without significant damage.
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RE: SHUTOFF HEAD POINT
http://virtualpipeline.spaces.msn.com
RE: SHUTOFF HEAD POINT
RE: SHUTOFF HEAD POINT
RE: SHUTOFF HEAD POINT
http://virtualpipeline.spaces.msn.com
RE: SHUTOFF HEAD POINT
RE: SHUTOFF HEAD POINT
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RE: SHUTOFF HEAD POINT
As you, others and myself are well aware, the shut-off point on many pump curves is just an arbitary point and doesn't serve any real purpose. Your suggestion of a three point test is more than adequate to establish likely head at zero flow.
RE: SHUTOFF HEAD POINT
RE: SHUTOFF HEAD POINT
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RE: SHUTOFF HEAD POINT
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RE: SHUTOFF HEAD POINT
True, unless the pump head falls off at shutoff like many low flow/high head centrifugals.
RE: SHUTOFF HEAD POINT
I don't know about your pumps, but if I shut one off completely for no other reason then to check its head at zero flow, somebody downstreams gets "really upset". It probably doesn't really matter too much in any case, as they ain't supposed to run along down there for any length of time anyway, especially if they give poor system characteristics at low flow. Most of the time its good enough to know the maximum pressure you might get at shutoff, so its not a bad way to estimate shutoff head for most cases.
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RE: SHUTOFF HEAD POINT
It is a PD , DOES NOT DO THAT. Even thogh PD has valves relief or not.
It is a Centrifugal Pumps Medium Presure and Low Presure Pump, Do but it is a new pump, it is better to ask to Pump representative or verify in Intruction Manual of the pump.
Mechanicals seal could fail if your test take so long.
It is a old pump Centrifugal Pump, it is very often that pumps does not meet Shut off Values.
It is a Axial Pump or Mixed ( vertical turbine) Pumps, you should verify if you could do. In the first case it is very often that could not do that. For mixed pumps you should check Thrust load and Power rating behavior before do that.