Trailer brake valve

An inlet connection (24) works with a reserve pipe (20) and a connection (26) for a reservoir (28). A first outlet connection (OC) (37) operates brake control pressure for a service brake cylinder (46). A second OC (54) operates a release pipe that leads to spring brake cylinders. An emergency brake device (3) has a piston structure with a switching piston (4) affected by pressure in the reservoir.