Samson EB 8075 EN, Mounting And Operating Instructions

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EB 8075 EN 3-1
Design and principle of operation
3 Design and principle of oper-
ation
The Type 3591 Globe Valve is preferably
combined with a Type 3271 Pneumatic Actu-
ator or a piston actuator.
The Type 3591 Valve uses a piston (5),
which moves within a cage (124), as the
closure member. The piston is pressure-
balanced as standard. The piston stem (36)
connected to the actuator stem by a stem
connector. The piston stem is sealed by either
a PTFE or graphite packing (15), which is
either self adjusting or can be adjusted
manually.
The medium flows through the valve as indi-
cated by the arrow on the body. A change
in the signal acting on the actuator causes
the piston to move. The piston position and
cage shape determine the released
cross-section and the flow rate with it.
The Type 3591 Valve is available either with
a clamped or flanged seat (4). The seat is
inserted into the seat bridge in the version
with clamped seat. The seat and cage are
clamped into place by tightening the body
nuts (14). The seat of the version with
flanged seat is bolted into the seat bridge.
The cage (124) is suspended in the valve
body (1) (see Fig. 3-1 and Fig. 3-2).
The actuator is connected using a special
assembly (60), which varies depending on
the mounted actuator. These assemblies are
fitted with an external anti-rotation fixture for
the piston stem.
The valves in valve sizes NPS 16 (Class 300
to 900) and NPS 20 (Class 150 to 900) to
32 (Class 150) can be equipped with addi-
tional lifting eyelets (148) to facilitate lifting
and transporting.
Legend for Fig. 3-1
1 Valve body
2 Bonnet
4 Seat
5 Piston
17 Body gasket
44 Ring (pressure balancing)
45 Gasket (pressure balancing)
49 Screw (pressure balancing)
50 Washer (pressure balancing)
60 Yoke assembly with anti-rotation fixture
124 Cage
126 Gasket between cage and bonnet
160 Screw