Cryogenic valves with modular extended stems

A valve, comprising:

• a valve body;
• a bonnet coupled to the valve body and including an inner surface;
• a valve stem extending through the bonnet and formed by a plurality of stem assemblies that include a plurality of modular stem assemblies stacked together, wherein each of the plurality of modular stem assemblies includes:
• a stem including a first end and a second end;
• a first disk connector coupled to the first end of the stem, wherein the first disk connector defines a modular slot configured to receive a head of another of the plurality of stem assemblies, and wherein the first disk connector has a first outer radial surface defined by an outer diameter to slidably engage the inner surface;
• and
• a second disk connector coupled to the second end of the stem, wherein the second disk connector includes a modular head configured to be received by a slot of another of the plurality of stem assemblies, wherein the second disk connector has a second outer radial surface defined by the outer diameter to slidably engage the inner surface.