Technical Manual
MT 188-E
4
1.0 INTRODUCTION
This manual aims at supplying essential information on the
installation, commissioning, disassembly, reassembly, and
maintenance of the valve
SBC 187
.
Moreover, it is deemed suitable to provide the reader with a brief
description of the main features of the valve and its accessories.
1.1
MAIN FEATURES
This is a device immediately blocking the gas flow, either if pressure
inside a piping reaches the preset value for its tripping due to any fault
or if it is enabled manually.
The main features of this valve are:
•
Design pressure
PS
: 220 bar;
•
Operating temperature: -20°C / + 60 °C;
•
Ambient temperature: -20°C / + 60 °C;
•
Tripping due to pressure increase and/or decrease
•
Tripping range due to pressure increase
Wdo
: 2 / 90 bar;
•
Tripping range due to pressure decrease
Wdu
: 0.2 / 90 bar;
•
Accuracy (
AG
): 1% of the calibration value in case of
pressure increase; 5% of the calibration value in case of
pressure decrease;
•
External manual bypass by means of a hand wheel to
obtain pressure balancing and ease the restoration of the
device;
•
Manual tripping control by means of push-button.
1.2
OPERATION OF THE VALVE SBC 187
(Fig. 1)
The slam-shut device consists of an obturator
A
, a control head
B
, a
lever mechanism system for the release
C
and a restoration system
D
controlled manually through the lever.
Fig. 1
The pressure of the circuit to be controlled acts on the control head
with a force opposing the forces of the setting springs for maximum
and minimum pressure calibrated to the pre-set values.
The translation movement causes the shifting of the lever mechanisms
controlling the release
E
of the entire mobile system freeing the
obturator, which closes due to the action of the spring
F
.
In order to restore the device, act on the lever
D
after having balanced
the pressure on the obturator by feeding pressure through the manual
bypass storage system with which the valve is equipped.
After the restoration close the bypass.
Fig. 3 BYPASS
The release can be controlled also manually using the suitable button.
Fig. 2
