Samson 3331/BR 31a, 3331/3278 Mounting And Operating Instructions

Pneumatic Control Valve Type 3331/BR 31a
Special version Type 3331/3278

Type 3331 Butterfly Valve

Mounting and
Operating Instructions

EB 8227 EN

Edition July 2004

Fig. 1 · Type 3331/BR 31a (below) and Type 3331/3278 (top)

Contents Page

1 Design and principle of operation . . . . . . . . . . . . . . . . . . . 4

2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2.1 Assembling butterfly valve and rotary actuator . . . . . . . . . . . . . . 6

2.1.1 Type 3331-BR 31a, Type SRP . . . . . . . . . . . . . . . . . . . . . . 6

2.1.2 Type 3331/3278 . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2.2 Mounting position . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.3 Test connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.4 Loading pressure connection . . . . . . . . . . . . . . . . . . . . . . 8

3 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

3.1 Changing the fail-safe position . . . . . . . . . . . . . . . . . . . . . 8

4 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

4.1 Packing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

4.2 Removing the butterfly valve. . . . . . . . . . . . . . . . . . . . . . . 9

5 Customer inquiries . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2 EB 8227 EN

Contents

Note:

Non-electrical actuators and valves do not have their own potential ignition source accord

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ing to the risk assessment in the rare incident of an operating fault, corresponding to EN
13463-1: 2001 paragraph 5.2, and therefore do not fall within the scope of the European
Directive 94/9/EC.
Refer to paragraph 6.3 of EN 60079-14:1977 VDE 0165 Part 1 concerning connection to
equipotential bonding system.

EB 8227 EN 3

Safety instructions

General safety instructions

4

The control valve may only be mounted, started up or serviced by fully
trained and qualified personnel, 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 mounting and operat

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ing instructions, particularly those concerning assembly, start-up and main

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tenance, must be observed.

4

The control valves fulfill the requirements of the European Pressure Equip

­ment Directive 97/23/EC. Valves with a CE marking have a declaration of
conformity that includes information about the applied conformity assess

­ment procedure.
The corresponding declaration of conformity can be viewed and down

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loaded on the Internet at http://www.samson.de.

4

For appropriate operation, make sure that the control valve is only used in
areas where the operating pressure and temperatures do not exceed the op­erating values which are based on the valve sizing data submitted in the or­der. The manufacturer does not assume any responsibility for damage
caused by external forces or any other external influence! Any hazards
which could be caused in the control valve by the process medium, operat­ing pressure, signal pressure or by moving parts are to be prevented by
means of the appropriate measures.

4

Proper shipping and appropriate storage of the control valve are assumed.

Caution!

4

For installation and maintenance work on the valve, make sure the relevant
section of the pipeline is depressurized and, depending on the process me

­dium, drained as well. If necessary, allow the control valve to cool down or
warm up to reach ambient temperature prior to starting any work on the
valve.

4

Prior to performing any work on the valve, make sure the supply air and
control signal are disconnected or blocked to prevent any hazards that
could be caused by moving parts.

1 Design and principle of opera

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tion

The pneumatic control valve consists of a
Type 3310 Butterfly Valve and either a
Pfeiffer Type BR 31a Pneumatic Actuator or
a SAMSON Type 3278 Pneumatic Actuator.

The control valve is primarily intended for
throttling or on-off service in the process en

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gineering industry and industrial applica

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tions.
It is suitable for liquids, vapors, and gases

with temperatures from −10 to +400 °C and
with nominal pressures from PN 10 to 40.

The butterfly valve in nominal sizes DN 100
to 400 can be designed depending on the
application with a swing-through or an­gle-seated/low-noise butterfly disc. The ver­sion used can be identified by a symbol on
the butterfly valve’s nameplate.

The process medium flows through the but­terfly valve. The signal pressure acting on
the pneumatic actuator determines the posi­tion (opening angle) of the butterfly disc (8)
and the flow rate across the free area be

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tween disc and body (1).
The shaft is sealed by a packing (5). The ac

­tuator motion is transmitted over a square­ended shaft. In Type 3331/3278, a shaft
with feather key (4.1) is used to transmit the
motion from the actuator to the shaft.

Fail-safe positions:

The fail-safe position of the control valve
upon failure of the supply air is determined
by the version of Type 3331/BR 31a (sin

­gle-acting Type SRP) or depending on how
the rotary actuator is attached for
Type 3331/3278.

Valve CLOSED without supply air

The actuator springs close the valve when
the pressure is relieved from the rotary actu

­ator or when the supply air fails.
The valve is opened opposing the force of
the actuator springs as the signal pressure
increases.

Valve OPEN without supply air

The actuator springs open the valve when
the pressure is relieved from the rotary actu­ator or when the supply air fails.
The valve is closed opposing the force of the
actuator springs as the signal pressure in­creases.

4 EB 8227 EN

Design and principle of operation