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

2 comments:

  1. In June 2008 we decided to purchase a water pump submersible to be installed in our well of drinkable water. We did a market survey and found out that although the price, this brand pumps offered some assurance of quality. In some cases the price difference came to be 1/3 of the price that the pump Pedrollo Sumo cost. The Water Pump Pedrollo cost 1,084€, while other brands had pumps with the same details for 350€. We decided to invest in quality in order to have a pump that lasts several years.
    In April 2013, the pump motor burned, because of a water leak into the pump frame!! So the Pump Pedrollo Sumo didn’t even lasted five years. Lasted precisely four years and 10 months.
    So a Pump who cost the triple of the price of another cheaper brand at least should last double if not triple of the time. Considering that a cheap pump would last twice as long as the warranty, so….four years and considering that Pedrollo pump should last at least triple the time of cheap pump, then the Pedrollo pump should at least 12 YEARS ....

    Come into contact with Pedrollo directly to Italy and we were told that was already passed the warranty period and lamentably all the situation but couldn’t do nothing. We were also told that at some point Pedrollo identified several problems with these pumps, but nothing was said to the customer, like an honest brand would do!!!!! Right?????
    What is at stake is not warranty and obligatoriness to provide assistance, but is the "good" name of the brand and the quality of their products. So it becomes obvious that the Water Pumps Pedrollo not have the quality that should have according the price they cost, which in itself is quite high.
    So in short what I’m trying to show with our experience is if you buy a pump Pedrollo you take the risk that only last 5 years and no more. But off course if you buy a chipper pump, lets say 1/3 of the price for shore it going to last at least four years and perhaps more……

    ReplyDelete
  2. Good day Joao,
    Thank you for your post.
    It is common for users to blame pump failures on the pump unit itself without providing the full information.
    This writer does not represent Pedrollo Pumps in your territory, however he has over 38 years of experience in this field and is able to assist you in
    determining the reason for failure. Please note that a pump does not normally leak water into a motor after successfully operating for 5 years.
    Normally there are other factors which lead to the failure.

    Should you really wish to understand your problem, please describe the pump installation.
    Please answer the following questions:-
    1) How deep is the pump submerged?
    2) What is the measurement from the top of the water level in the pump sump (Lowest/highest)to the highest point the pump is required to pump?
    3) What is the length of the discharge pipe?
    4) Is there a non return valve installed on the discharge pipe?
    5) Is there an isolation valve installed on the discharge pipe?
    6) What is the internal diameter of the discharge pipe?
    7) Do you have an ammeter on the pump control panel? If so what was the operating amp reading when operating?
    8) Is there electrical overload protection built into the control panel?
    9) Please advise the model number of the installed pump and the voltage of the motor.

    Thank you for your post, we look forward to your responses. We are only responding to assist you in determining the real reason for the pump failure.

    Regards
    Evan Lewis
    (Evan Lewis & Associates CC administrators of www.pedrollopumps.com)
    Evan Lewis & Associates CC is an Independent Pedrollo Pump Supplier for SOUTHERN AFRICAN MARKETS only and not a Pedrollo S.P.A. owned business)

    ReplyDelete