Overpressure shutoff and relief valve assembly

A valve assembly comprising:

• a housing having an inlet, a first outlet, and a passageway extending therebetween, the passageway having a first inner diameter at the inlet and a second inner diameter at the first outlet;
• a first poppet valve disposed in, and adapted to selectively seal, the inlet;
• a second poppet valve disposed in, and adapted to selectively seal, the first outlet;
• a rigid stem coupled to the first poppet valve and the second poppet valve, the stem extending through the passageway;
• and
• a biasing member coupled to the second poppet valve, the biasing member adapted to exert a force sealing the second poppet valve.

A valve assembly comprising:

• a housing having:
• an inlet with a substantially circular shape;
• a first outlet with a substantially circular shape;
• and
• a passageway extending therebetween, the passageway having:
• a first inner diameter at the inlet;
• and
• a second inner diameter at the first outlet, the first inner diameter larger than the second inner diameter;
• a first poppet valve disposed in, and adapted to selectively seal, the inlet;
• a second poppet valve disposed in, and adapted to selectively seal, the first outlet;
• a rigid valve stem coupled to the first poppet valve and the second poppet valve, the valve stem extending through the passageway;
• and
• a biasing member coupled to the second poppet valve, the biasing member adapted to exert a force sealing the second poppet valve in the first outlet and opening the first poppet valve in the inlet.