Samson 36-8 Mounting And Operating Instructions

Safety Excess Pressure Valve (SEV)
Type 36-8

Fig. 1 · Type 36-8 Excess Pressure Valve

Mounting and
Operating Instructions

EB 2546-2 EN

Edition April 2007

Design and principle of operation

1 Design and principle of

operation

The excess pressure valve consists of a
spring-loaded globe valve with a balanced
plug and an actuator with an operating dia
phragm and a safety diaphragm.

The excess pressure valve is used to maintain
the pressure upstream of the valve to an ad
justed set point value. The valve opens when
the upstream pressure rises.

The process medium flows through the valve
between the seat(2)andthe plug (3) in the di
rection indicated by the arrow. The position
of thevalveplug determines the flow rate.The
upstream pressure p
control line (12) to the operating diaphragm
(11.1) and is converted into a positioning
force which is used to move the valve plug,
opposing the force of the positioning springs
(7). The spring force is adjustable at the set
point adjuster (6).

4

4

4

is transmitted via the

1

The regulators must be mounted, started up and serviced by fully trained
and qualified personnel only, observing the accepted industry codes and
practices. Make sure employees or third persons are not exposed to any
danger.
All safety instructions and warnings in these instructions, particularly those
concerning installation, start-up, and maintenance, must be observed.
Any hazards which could be caused in the excess pressure valve by the
process medium or operating pressure are to be prevented by means of
appropriate measures.
For appropriate operation, make sure that the regulator is only used in
applications where the operating pressure and temperatures do not
exceed the operating values based on the valve sizing data submitted in
the order.
Proper shipping and appropriate storage are assumed.

The regulator has two diaphragms (11.1) op
erating independently from one another.
Continued operation is possible even should
one diaphragm fail. To recognize a ruptured
diaphragm, a diaphragm rupture indicator
or optionally a pressure switch to signalize a

­rupture is installed in the intermediate ring

(11.3 ).

Typetestng:

­The regulator has been typetested as a safety

excess pressure valve (SEV) by the German
Technical Inspectorate (TÜV) according to
AGFW specifications.

­The test mark is available on request.

-

2 EB 2546-2 EN

Design and principle of operation

1

p

1

12

Drawn turned
by 90° into the
plane of projection

1 Valve body
2 Seat
3 Plug
4 Plug stem
5 Balancing bellows
6 Set point adjuster
7 Positioning springs
8 Bellows
9 Fastening nut
10 Support
11 Actuator housing

11.1 Diaphragms

11.2 Diaphragm rupture
indicator

11.3 Intermediate ring

12 Control line

3

p

2

2

4

6

5

7

8

9

10
11

11.1

11.2

11.3

Fig. 2 · Sectional drawing

EB 2546-2 EN 3