An apparatus for freeing a seized valve having an elongate valve actuating stem (10) projecting out of the valve comprises means for repeatedly applying an impact force to the valve actuating stem along its longitudinal axis.

In order to free a seized valve, an inspection port (52) is formed in a wall of the valve body and the areas where the valve is seized are determined.

An apparatus for freeing a seized valve having an elongate valve actuating stem (10) projecting out of the valve comprises means for repeatedly applying an impact force to the valve actuating stem along its longitudinal axis.

In order to free a seized valve, an inspection port (52) is formed in a wall of the valve body and the areas where the valve is seized are determined.

Valve seized or inoperative (ABS functioning).

Valve seized or inoperative (ABS functioning).

The valve module may have a first intake valve, a second intake valve, a third intake valve, a first exhaust valve and a second exhaust valve.

The valve can be a passive bi-directional valve, such as a dome valve, or a passive unidirectional valve.

Pressure relief valve (discharge valve

The flushing valve comprising an inlet valve, an outlet valve and a timer valve.

A valve stem (32), a valve stem-valve seat assembly (30), and a valve using the stem-valve seat assembly (30) are provided.

Pressure relief valve (discharge valve

Pressure relief valve (discharge valve

The valve has a valve seat and a valve member.

The first pre-valve ullage is connected to the post- valve ullage by the first valve and the second pre-valve ullage is connected to the post- valve ullage by the second valve.