One-way valves

A pump comprising;

• an inlet valve and an outlet valve;
• and
• a pumping chamber serviced by the inlet valve and the outlet valve;
• wherein at least one of the inlet valve and the outlet valve is a one-way valve comprising:
• an upstream portion comprising
• an upstream inlet, and
• a first engaging portion about the upstream inlet;
• a movable element comprising
• a second engaging portion engageable with the first engaging portion to impede reverse flow,
• openings, and
• first bias-contacting portions;
• a downstream portion comprising
• a downstream outlet, and
• second bias-contacting portions;
• a bias
• acting between the first bias-contacting portions and the second bias-contacting portions to urge the movable element against the first engaging portion, and
• surrounding an interior open to the downstream outlet;
• and
• flow paths
• via the openings, and
• from outside of the first engaging portion, and
• to the interior, and
• passing inboard of an upstream end of the bias.

A waterjet cutting apparatus comprising:

• a cutting head;
• and
• a pump to supply the cutting head;
• wherein the pump comprises an inlet valve, an outlet valve and a pumping chamber serviced by the inlet valve and the outlet valve;
• and
• at least one of the inlet valve and the outlet valve is a one-way valve comprising:
• an upstream portion comprising
• an upstream inlet, and
• a first engaging portion about the upstream inlet;
• a movable element comprising
• a second engaging portion engageable with the first engaging portion to impede reverse flow,
• openings, and
• first bias-contacting portions;
• a downstream portion comprising
• a downstream outlet, and
• second bias-contacting portions;
• a bias
• acting between the first bias-contacting portions and the second bias-contacting portions to urge the movable element against the first engaging portion, and
• surrounding an interior open to the downstream outlet;
• and
• flow paths
• via the openings, and
• from outside of the first engaging portion, and
• to the interior, and
• passing inboard of an upstream end of the bias.