24
September 2020
Installation, Operation and Maintenance Manual
MAN 571_EAC Rev. 1
Operation and Use
Section 3: Operation and Use
Figure 19
Torque Limiting Device
A pressure reducer or a “torque limiting device”(Biffi patent) can be supplied when the
gas supply pressure varies in a wide range and when the actuator output torque must
not exceed a fixed value in order not to damage the valve. The pressure reducer limits
the output torque of the actuator by reducing the gas supply pressure at a preset value.
The torque limiting device consist of 2 valves, one for each gas-over-oil tank, which stop
the gas flow coming from the pneumatic control valves of the actuator and exhaust the
gas enclosed in the gas-over-oil tanks when the output torque exceed the preset value.
When the gas supply to the actuator is not always available, a storage tank engineered
and manufactured according to the applicable code and working conditions is provided.
For any particular requirements it is advisable to contact Biffi sales offices, wich will provide
the most suitable and convenient solutions to the various needs. (Figure 19).
