Design And Principle Of Operation - Samson 46-5 Mounting And Operating Instructions

Design and principle of operation

3 Design and principle of oper-
ation
The combined regulators basically consist of
a valve body (1) with restriction (1.2) and
balanced plug (3) as well as a closing actua-
tor (6) with an operating diaphragm (6.1).
In Type 46-5, the set point springs (8) inte-
grated into the valve determine the set point.
Whereas, in Type 46-6, the set point can be
adjusted by the set point springs (8) on the
actuator.
The regulators are used to limit the differen-
tial pressure and flow rate to the adjusted set
points. The valve closes when the differential
pressure (flow rate) increases.
The medium flows through the valve in the
direction indicated by the arrow. The areas
released by the restriction (1.2) and the
valve plug (3) determine the flow rate and
the differential pressure ∆p. The upstream
pressure is transmitted to the operating dia-
phragm (6.1) in the actuator over an exter-
nally routed control line (11). The pressure
downstream of the restriction (1.2) is trans-
mitted through a hole in the plug to the
low-pressure side of the operating dia-
phragm. The resulting differential pressure
creates a positioning force at the diaphragm
which moves the plug depending on the
force of the valve spring (5) or set point
springs (8). The maximum flow rate (flow
limitation) is adjusted at the restriction (1.2)
using the set point screw (17). The cross-sec-
tion of the valve is changed in such a way
that the differential pressure and the differen-
tial pressure created at the restriction are
12
identical when the required maximum flow
rate exists. An overload protection (excess
pressure limiter) (6.4) in the actuator protects
the seat and plug from overload during ex-
ceptional operating conditions that could
lead to valve or plant damage.
Legend for Fig. 2
1 Valve body
1.1 Connection nut with seal and
welding end
1.2 Restriction
2 Seat
3 Plug
4 Plug stem
5 Valve spring
6 Actuator
6.1 Operating diaphragm
6.2 Actuator stem
6.3 Nut
6.4 Internal excess pressure limiter
(overload protection)
8 Set point springs
9 Spring plate
10 Set point adjuster for differential
pressure
11 Control line (high pressure)
14 Bottom section with manual adjuster
15 Screws
16 Lock nut
17 Set point screw for flow rate
(hexagon socket screw SW 4)
18 Cap
19 Manual adjuster
20 Spindle
21 Support
25 Stopper for plug
x = Turned into the plane of projection
EB 3130 EN