Suction side and discharge side pump pressure

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TSN79
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Consider a closed system (central heating). Before the pump is started the static pressure is 2.0 bars. Say the system head loss is 0.6 bars. When the pump starts, will the suction side pressure and the discharge pressure each read half the total head loss (1.7 and 2.3 bars)? Or will the head loss be split unequally for some reason?
 

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TSN79 said:
Consider a closed system (central heating). Before the pump is started the static pressure is 2.0 bars. Say the system head loss is 0.6 bars. When the pump starts, will the suction side pressure and the discharge pressure each read half the total head loss (1.7 and 2.3 bars)? Or will the head loss be split unequally for some reason?
Depends if the resistance to flow is upstream or downstream of the atmospheric pressure refill - or what fraction is upstream versus downstream.
 
In a central heating system there should exist an expansion vessel. The point that the vessel is connected to the piping determines the pressures at the various point of the network.

More specifically, if the vessel is correctly inflated, it keeps it's pressure constant (before and after the pump operation) and the connection point to the network keeps this pressure (2bar).

So, if the vessel is connected near the pump suction, then suction pressure will remain constant and the discharge pressure will be 2,6bar.