Adjusting The Flow Limitation - Samson 42-34 Mounting And Operating Instructions

1.3
16
1.1
24
1.2
17
Set point screw for
1.1
flow rate
1.2 Lock nut
1.3 Cap
16 Set point springs
Fig. 7-2: Set point adjusters for flow rate and
differential pressure
7.1.2 Adjusting the flow lim-
itation
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 7-2 and
Table 7-3) by turning the set point screw
EB 3013 EN
Set point adjuster
17 for differential
pressure
24 Diaphragm stem
(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 gener-
ally 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 across the plant is known, use the
adjustment diagrams for water (Fig. 7-4 to
Fig. 7-9).
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.
Operation
7-3