Adjusting The Flow Limitation; Based On A Known Plant Pressure Drop - Samson 42-34 Mounting And Operating Instructions

Operation
7.1.2 Adjusting the flow
limitation
NOTICE
!
Set point adjustment is always based on a
closed restriction (1.4).
How to proceed:
1. Unscrew the cap (1.3) and undo lock nut
(1.2).
2. Turn the set point screw (1.1) clockwise
to block the flow.
3. To achieve the maximum flow rate, all
control and shut-off valves as well as all
consumers including the motorized valve
must be open (to ensure minimum drag
in the plant).
4. Close the bypass valve, if installed.
5. Adjust the set point (see Table 6) by turn-
ing the set point screw (1.1) one turn at
a time. Check the flow rate at the heat
meter (reading of flow measuring unit).
Adjust the flow rate in smaller steps until
the required flow rate is constant ( ±2 %
deviations are generally acceptable).
Increase the differential pressure set point if
the maximum flow rate is not reached.
6. After reaching the required flow rate, se-
cure the set point screw (1.1) using the
lock nut (1.2). Screw cap (1.3) back on.
7. Lead-seal the valve and actuator.
To adjust the flow rate limit when the pres-
sure drop of the plant is known, use the ad-
34
justment diagrams for water (Fig. 16 to
Fig. 11).
Note
Using the set point screw (1.1)
− Turn clockwise :
The restriction closes. The flow rate drops.
− Turn counterclockwise :
The restriction opens. The flow rate rises.
Note
We recommend adjusting the flow rate with
the aid of a heat meter.
7.1.3 Based on a known plant
pressure drop
To adjust the flow rate limit when the pres-
sure drop of the plant is known, use the ad-
justment diagrams for water (Fig. 16 to
Fig. 11).
How to proceed:
1. Unscrew the cap (1.3).
2. Undo lock nut (1.2) and turn the set point
screw (1.1) clockwise as far as it will go
to close the restriction.
3. Adjust the flow rate according to the val-
ue determined (number of turns in coun-
terclockwise direction ).
EB 3013 EN