Turbine and diesel start systems
Gas turbines are used on larger marine vessels in addition to diesel engines to achieve higher speeds. The turbines are started by large volumes of compressed air at low pressure. Even though diesel engines need lower flows to start they have the same high requirements relative to pressure and flow.
Turbine start system
The SAB turbine start reducing station was designed for the LM 2500 gas turbine but can be adapted to enable the start for alternative turbine suppliers.
The two stage design of SAB’s turbine start reducing station provides a very accurate outlet pressure even on highly unsteady inlet pressures and flow rates. The Nickel Aluminium Bronze reducing station is equipped with SAB standard cartridge valves in a monoblock housing. They are designed for mass flows up to 2 kg/s at an outlet pressure of 3,5 bar.
Innovative design provides high flow to outlet allowing multi start possibilities, without the requirement for higher than required initial outlet pressure. This is achieved by the addition of a regulation mechanism that increases outlet area of the second stage at high flows. The system is totally integral to the manifold block without need of any additional mechanism.
Diesel start system
SAB’s Diesel Start Systems are usually two stage reducing stations, which reduce the pressure from up to 400 bar down to 10 bar or less. The mass flows of air are usually below 1 kg/s. It is of essence that the outlet pressure remains stable even at high flows and dropping inlet pressures.
For smaller navy ships and on submarines we supply single stage reducing stations.
On some Diesel and Turbine Start Reducing Stations SAB used Automatic Stop Valves in order to close the outlet when the pressure reducer is leaking. This prevents the safety valves from blowing off and avoids the loss of compressed air.
More inserts: see SUMMARY
SAB has a full in-house test facility which includes the equipment required for the complete test of the Diesel and Turbine Start Reducing Stations. The test takes into account full strength, tightness, functional and flow tests. It operates at pressures up to 400 bar and flows higher than 50 kg/s.
The flow test facility consists of a 400 bar compressor unit, a cylinder bank allowing for 2400 litres.