Fluid flow restrictor device - has return pipe with valve between widest and narrowest points opening at predetermined pressure

摘要

The flow restrictor device has a main passage (8) gradually widening, with a return pipe (9) joining onto the passage at points near where it is widest and narrowest. When the pressure difference between these points reaches a predetermined value a stop valve (11) between them in the return pipe opens. The flow restrictor device has a main passage (8) gradually the return pipe when seen from the narrowest part (7), and the passage can be venturi-shaped. The stop valve can be of the spring-loaded non-return type, the spring-loading being adjustable from outside.