Excess flow valves

摘要

The present invention relates to an excess flow valve (EFV) (1) adapted to be installed in a service line of a natural gas distribution system serving an existing structure, said EFV comprising:
a cylindrical housing (10) having a first length (6) and a second length (8) and a through hole (11) therethrough for passage of gas;
the EFV being engaged in said through hole of said first length; and
an expandable wall (14) forming part of said second length;
wherein said expandable wall can be expanded and fixed in said service line.