However, more recent research suggests that, by using incremental increases in rotation and making a few limb movements, adaptation can occur with almost no feelings of nausea. The old research done on about 30 subjects simply went from zero to full rotation. Moreover, the adaptation can be simultaneous with non- rotational adaptation. So, moving in and out of the rotating habitat for maintenance or whatever is no problem.
Plan ahead for flow meters For new systems that do not have a flow meter, install flanges that are designed for an orifice plate in a straight part of the pipe see next Figure and do not install the orifice plate.
In the future, whoever trouble-shoots the pump will have a way to measure flow without the owner having to incur major downtime or expense.
Avoid pockets and high points Avoid pockets or high point where air can accumulate in the discharge piping. An ideal pipe run is one where the piping gradually slopes up from the pump to the outlet. This will ensure that any air in the discharge side of the pump can be evacuated to the outlet.
Water hammer Be aware of potential water hammer problems. This is particularly serious for large piping systems such as are installed in municipal water supply distribution systems.
These systems are characterized by long gradually upward sloping and then downward sloping pipes. This will avoid water hammer during the initial start and damage to the piping system. The right pipe size The right pipe size is a compromise between cost bigger pipes are more expensive and excessive friction loss small pipes cause high friction loss and will affect the pump performance.
Generally speaking, the discharge pipe size can be the same size as the pump discharge connection, you can see if this is reasonable by calculating the friction loss of the whole system. For the suction side, you can also use the same size pipe as the pump suction connection, often one size bigger is used ref.
If you know the cost of energy and the purchase and installation cost of the pipe you can select the pipe diameter based on a comparison of the pipe cost vs power consumption.
Pressure at high point of system Calculate the level of pressure of the high point in your system. The pressure may be low enough for the fluid to vaporize and create a vapor pocket which will be detrimental to the performance of the system.
The pressure at this point can be increased by installing a valve at some point past the high point and by closing this valve you can adjust the pressure at the high point.
Of course, you will need to take that into account in the total head calculations of the pump. See this video showing this phenomena in action. Pump pressure rating and series operation For series pump installations make sure that the pressure rating of the pumps is adequate.
This is particularly critical in the case where the system could become plugged due to an obstruction. All the pumps will reach their shut-of head and the pressure produced will be cumulative.
The same applies for the pressure rating of the pipes and flanges. Inadequate pump suction submersion There is a minimum height to be respected between the free surface of the pump suction tank and the pump suction.
If this height is not maintained a vortex will form at the surface and cause air to be entrained in the pump reducing the pump capacity. Pump selection Select your pump based on total head not discharge pressure and flow rate.
The flow rate will depend on your maximum requirement. Total head is the amount of energy that the pump needs to deliver to account for the elevation difference and friction loss in your system ref. Pump selection starts with acquiring detail knowledge of the system.
If you are just replacing an existing pump then of course there is no problem. If you are replacing an existing pump with problems or looking for a pump for a new application then you will need to know exactly how the systems is intended to work.
The next figure is a typical example: Typical example of flow schematic used for total head calculations. The control method is important on-off, control valve, re-circulating, variable speed as it may affect your selection. Besides the system sketch, here is a pump data sheet that you can use to record some of the data.
Depending on the industry or plant that you work in, you will be forced to either select a certain type of pump or manufacturer or both.
Manufacturers are normally a very good source of information for final pump selection and you should always consult with them, do your own selection first and confirm it with the manufacturer. They can help you select the right type, model, and speed if you have all the operating conditions and if not they will rarely be able to help you.
This form will help you gather all the information pertinent to operation and selection of your pump.IJCEE-IJENS © December IJENS I J E N S I J E N S. A collection of do it yourself marine projects.
Anchor Alarm, Battery Saver, Bilge Alarm, dinghy Saver, Fire Prevention, Head Flushing, Mildew, Propane switch, Pump. Variable Speed Pump Selection - Parts 1 - 3 This tutorial takes a different approach to pump selection for VFD operation.
Part 1 addresses constant pressure / variable flow while Part 2 addresses variable pressure / variable flow. Nov 09, · Pumps are generally grouped into two broad categories—positive displacement pumps and dynamic (centrifugal) pumps.
Positive displacement pumps use a mechanical means to vary the size of (or move) the fluid chamber to cause the fluid to flow.
Edwards & Young Racing Blog – Seattle, WA. - Interactive Blog For Our Fellow Racers – Small-Block Chevy Madness. Centrifugal pumps are widely used in industrial and domestic situations.
Due to the characteristics Fluid Mechanics Lab Experiment (9): Centrifugal pump 4 Instructors: Dr. Khalil M. ALASTAL The pump should begin to run more smoothly as the experiment progresses).
5. Select the (Go) icon to record the sensor readings and pump settings.