Based On A Known Plant Pressure Drop; Based On An Unknown Plant Pressure Drop - Samson 42-34 Mounting And Operating Instructions

Operation
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. 7-4 to
Fig. 7-9).
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 ).
4. Secure restriction setting using the lock
nut (1.2) at the set point screw (1.1).
Screw cap (1.3) back on.
5. Lead-seal the set point screw at the cap
(1.3).
NOTICE
!
To determine the flow limitation to be ad-
justed and for Type 42-34 additionally the
differential pressure set point, the differential
pressure across the restriction (Δp
must be added to the known pressure drop
across the plant (Δp
the differential pressure at the restriction is
assumed to be 0.2 bar.
The curves of the flow ranges in the follow-
ing diagrams (Fig. 7-9 to Fig. 7-4) apply to
0.1, 0.2 and 0.5 bar.
7-4
restriction
). From experience,
plant
7.1.4 Based on an unknown
To adjust the flow rate limit when the pres-
sure drop across the plant is not known.
Procedure
1. Unscrew the cap (1.3).
2. Undo lock nut (1.2) and turn the set point
screw (1.1) clockwise () to close the re-
striction.
3. Completely open the motorized valve.
4. Open the restriction initially 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).
If the maximum flow rate is not reached,
the differential pressure set point (in
Type 42-34) must be increased.
5. After reaching the required flow rate, se-
cure the restriction setting using the lock
nut (1.2). Screw cap (1.3) back on.
6. Lead-seal the set point screw at the cap
(1.3).
)
7. Lead-seal the actuator at the spindle.
plant pressure drop
EB 3013 EN