The Valmetal Head Pressure Calculator is used to select the correct pipe size and pump model for the transfer of liquid manure with centrifugal pumps.
- Select the manure condition, slump*, and type of pipe, then fill in the pipe length and desired flow rate.
- Fill in the elevation change from the bottom of the pump to the highest point in the system or storage pit.
- Insert the quantities of pipe fittings, enter the interior diameter of the proposed pipe.
- The ideal liquid speed is less than 7 ft/sec (2.1 m/sec), do not exceed 10 ft/sec (3 m/ sec).
Adjust pipe size accordingly.
- For sand-laden manure, adjust the pipe size or flow rate to ensure the liquid speed is 7 – 10 ft/sec (2.1 to 3 m/ sec).
Most general-purpose manure pumps operate up to 25 ft (7.2 m) TDH for smaller motors or up to 60 ft (18.3 m) TDH for larger motors. Adjust the pipe size or flow rate to reduce the required TDH in the system and to minimize motor size required. Special pumps are available to operate at higher TDH.
*Manure slump measurement:
- Set a 24” diameter smooth, flat disc on top of a pail so it is elevated above the floor.
- Pour the manure sample onto the disc until it overflows
- Wait 1 minute and measure the depth of the remaining manure at the center of the test disc.
It is important that samples are well agitated and are typical of the worst conditions expected.