Three speeds circulation pumps with flanges
NC, NCD
ENGINEERING INSTRUCTIONS
1. Introduction
The circulating pumps of the mentioned types are used for the flow of media within the systems of hot-water
heating, air-conditioning and ventilation. They are designed as single or double three-speed pumping
aggregates.
2. Pump installation
The pump has to be installed into the piping system with the pump axis 1-1 in horizontal position (Fig. 3). It
has to be installed into the straight piping section having the length of at least 5-10 D (D = nominal diameter of
the pump tube) from the knee. This will ensure its operation with minimum vibration and noise. The direction
of water flow through the pump must match the direction indicated by an arrow on the pump casing (Fig. 1 –
Pos. 1).
The pump must not be installed into the safety pumping systems. The nominal tube diameter should not be
smaller than the nominal diameter of the pump.
The connecting flanges are NP 6/10 (Fig. 1 – Pos. 8).
The NC and NCM pumps have a single hydraulic casing (Fig. 1 – Pos. 9).
The NCD, NCDM pumps have a double hydraulic casing (Fig. 2 – Pos. 11) where a tiltable flap is built-in (Fig.
2 – Pos. 10) tilting automatically, depending on the flow direction of one or another pump.
With an additional order a
cover can be supplied to be
used on the NCD and NCDM
pump types after dismantling a
defective motor. Upon closing
the opening on the hydraulic
casing, the neighbouring motor
can continue to operate in an
undisturbed manner.
The correct position of the
pump:
5
