A valve assembly (6000) for use with a valve body (7000) having a valve seat (7112) is disclosed, the valve assembly (6000) comprising: a cartridge (6200) threadably engaged with and extending away from the valve body (7000); a poppet (6500) slidably engaged with the cartridge (6200); a plate (6600) engaged with the poppet (6500); a plunger (6400) slidably engaged with the cartridge (6200) and slidably extending through the plate (6600); and a retainer (6450) captured between the plate (6600) and a surface of the poppet (6500), wherein the retainer (6450) is threadably engaged with the plunger (6400). The valve assembly (6000) can regulate fluid flow.