Never decrease the size of the suction of any pump, especially a centrifugal pump.
One of the most common mistakes we find when inspecting a pump which has failed prematurely is that the customer has decreased the suction size of the pump.
A pump with a 1" suction size should never be reduced to anything smaller than 1".
We always increase the suction pipe size in installations we do. A 1" pump suction would be fitted with a 1 1/4"or even a 1 1/2" pipe size. This ensures that the pump receives adequate fluid and that it operates at full design efficiency. A smaller suction pipe than the designed pump inlet will create cavitation, this in turn will create a vibration on the seal and the bearings.
Premature failure will result every time.
The next common problem on suction piping is the length of the suction pipe.
Always try to place the pump as close to the tank from which it is drawing the fluid. Try not to have any bends and limit the valves to one isolation and one non return if necessary. Also be very sure never to install a valve with a reduced bore. Ball valves can be purchesed with reduced or full bore. Make sure the suction valve is always a full bore.
Stick to these rules and you will have a happy pump unit.
For more assistance call 0826519841 or check out http://www.pedrollopumps.com/
Thursday, 22 December 2011
Tuesday, 20 December 2011
Pedrollo HFm High volume low head pumps.
The HF series of the Pedrollo Pump range is ideal for those applications where a pump unit capable of producing very high flow rates with relatively low heads is required.
Water features are typical of this type of application.
The HF and HFm (single phase) series is designed to provide very high flows at relatively low head (pressure) with highly efficient motors requiring low power demand.
These installations always demand a certain level of expertise in that one must follow the basic rule of centrifugal pump system design.
First be sure that your suction pipe is at least the size of the pump suction port. In other words if you have a 2" suction port, make sure your suction pipe is at least 2". It is no use reducing the pump suction to 1.5" (40mm) when the pump is designed to accept 2" (50mm) pipe. The throat of the impeller will be starved for every mm you reduce this suction pipe diameter. Also ensure that the suction is very short. The shorter the suction, the better. This pump must also be installed into an application where the water will flood the casing when the suction valve is opened. This is not a self priming pump and should not be installed above water level. A 500 mm to 800 mm water level above the level of the pump suction is ideal.
Secondly the discharge pipe should be sized to provide the correct back pressure on the pump so as to bring it into it's pump curve. In other words if one is trying to circulate water in a pond and the highest level of the discharge pipe is only 1 meter above the pump, be sure to reduce the pipe diameter on the discharge so as to provide the back pressure equivalent to the head curve. Lets say 3 or 4 meters.
For help with pipe length and size look for friction loss calculators on the internet or email our sales team and we will be glad to assist you.
The best way to set up this or any other centrifugal pump, is always to install a discharge valve (gate or diaphragm) and have an ammeter on the electrical installation. Once the pump is primed and running, check the operating amps and close the valve until they are either just below the full load current (amps) indicated on the pump tag, or 10 % below if the unit is to operate 24 hours a day. The only weakness doing ti this way is that someone can come in after you have set it up and open the valve. If the pump runs in overload for any length of time, the motor will stress, overheat and can burn out if allowed to function in this state long enough.
For more advise call us directly on 082 651 9841 or check out our website www.pedrollopumps.com
Water features are typical of this type of application.
The HF and HFm (single phase) series is designed to provide very high flows at relatively low head (pressure) with highly efficient motors requiring low power demand.
These installations always demand a certain level of expertise in that one must follow the basic rule of centrifugal pump system design.
First be sure that your suction pipe is at least the size of the pump suction port. In other words if you have a 2" suction port, make sure your suction pipe is at least 2". It is no use reducing the pump suction to 1.5" (40mm) when the pump is designed to accept 2" (50mm) pipe. The throat of the impeller will be starved for every mm you reduce this suction pipe diameter. Also ensure that the suction is very short. The shorter the suction, the better. This pump must also be installed into an application where the water will flood the casing when the suction valve is opened. This is not a self priming pump and should not be installed above water level. A 500 mm to 800 mm water level above the level of the pump suction is ideal.
Secondly the discharge pipe should be sized to provide the correct back pressure on the pump so as to bring it into it's pump curve. In other words if one is trying to circulate water in a pond and the highest level of the discharge pipe is only 1 meter above the pump, be sure to reduce the pipe diameter on the discharge so as to provide the back pressure equivalent to the head curve. Lets say 3 or 4 meters.
For help with pipe length and size look for friction loss calculators on the internet or email our sales team and we will be glad to assist you.
The best way to set up this or any other centrifugal pump, is always to install a discharge valve (gate or diaphragm) and have an ammeter on the electrical installation. Once the pump is primed and running, check the operating amps and close the valve until they are either just below the full load current (amps) indicated on the pump tag, or 10 % below if the unit is to operate 24 hours a day. The only weakness doing ti this way is that someone can come in after you have set it up and open the valve. If the pump runs in overload for any length of time, the motor will stress, overheat and can burn out if allowed to function in this state long enough.
For more advise call us directly on 082 651 9841 or check out our website www.pedrollopumps.com
Pedrollo CP 158 pressure pump systems
When selecting the popular CP range, it is important to recognise the designation between the three phase models CP and the single phase models CPm. The CPm 158 for example is one of the most popular pumps to use on whole house water systems. The unit provides sufficient volume to operate up to 5 taps at one time which is ideal for a normal two bathroom home.
More information can be found by following this link http://www.pedrollopumps.com/ or call 0826519841 during office hours for direct assistance.
Pedrollo Pumps
The high quality range of Pedrollo pumps is sold direct to consumers and resellers throughout Southern Africa by http://www.pedrollopumps.com/ based in Pinetown, KZN, South Africa. This internet distribution is fast and efficient delivering units all over Southern Africa via door to door courier services. In Johannesburg alone, it is far more cost effective to order direct from this service, the time, effort and expense of trying to cross town to reach a showroom or a reseller is easily offset by placing your order direct and receiving your product delivered to your door. You also know that you will have immediate telephonic backup to assist you with selection or technical advise as and when you need it.
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