5
Type BM5A
When the controlled pressure is within set values of
the slam-shut controller, the controller remains set and
prevents the rotation of the eccentric shaft, keeping
the valve open. When the controlled pressure varies
beyond setting limits, the controller releases the
eccentric shaft causing the valve close, following the
spring thrust.
The slam-shut controller has a manual release
push-button to quickly close the slam-shut valve
in case of emergency or during maintenance and
checking operations.
If the Type BM5A slam-shut valve is used with
pilot-operated pressure regulators, the supply
pressure to the pilot is taken from the downstream line
of the slam-shut valve. For this purpose, Type BM5A
slam-shut valve features a threaded hole which may
be used for the supply pressure to the pilot. This hole
is normally kept closed by a dowel.
Slam-Shut Controller
The Type BM5A slam-shut valves are equipped with
the OS/80X or OS/80X-PN Series slam-shut controller.
The controllers are supplied in different models
according to set ranges required. The Type BM5A
with DN 150 / NPS 6 body size is equipped with a
reinforced version Type OS/80X-R.
OS/80X or OS/80X-PN Series slam-shut controller is
used to keep the slam-shut valve shutter open. These
Series are designed to operate on Overpressure
Shutoff (OPSO) only, Underpressure Shutoff (UPSO)
only, or Overpressure and Underpressure Shutoff
(OPSO/UPSO) protection.
Transport and Handling
Follow established transport and handling procedures
to avoid any damage on the pressure-containing parts
by shocks or excessive external pressure or stress.
Use appropriate eyebolts to aid in the handling of
heavy equipment.
Protect built-up sensing lines and pressure
accessories (e.g. slam-shut controller) from shocks or
excessive external pressure or stress.
Figure 4.
Type BM5A Slam-Shut Valve and Type FL or FLA1 Regulator Operational Schematics
≥
4D
D
TYPE PS/79 OR PSA/79 PILOT
TYPE FL OR FLA1
BM5A SERIES
REGULATOR
SLAM-SHUT VALVE
INLET PRESSURE, P
u
REGULATOR MOTORIZATION
PRESSURE, P
m
STABILIZED PRESSURE, P
up
OUTLET PRESSURE, P
d
