A valve (1, 11) for conveying fluid, the valve (1, 11) comprising: a body (13, 131) that is integrally formed and defines a plurality of ports (13a, 13b, 13c, 131a, 131b, 131c), and defining a plurality of voids (13d, 13e, 13f, 13g, 13h, 13i, 13j, 13k, 13m, 13n, 13p, 13q, 131d, 131e, 131f, 131g, 131h, 131i, 131j, 131k, 131m, 131n, 131p, 131q), wherein the plurality of voids (13d, 13e, 13f, 13g, 13h, 13i, 13j, 13k, 13m, 13n, 13p, 13q, 131d, 131e, 131f, 131g, 131h, 131i, 131j, 131k, 131m, 131n, 131p, 131q) include cylindrical voids (13e, 13g, 13h, 13j, 13k, 13m, 131e, 131g, 131h, 131j, 131k, 131m) that have a central axis parallel to and collinear with a longitudinal axis of the body (13, 131); a bonnet secured to the body (13, 131) and defining a bonnet void; a diaphragm compressed between the bonnet and the body (13, 131); a first spring disposed in the bonnet void and configured to bias the diaphragm in a downward direction; and a spindle unit confined in the plurality of voids (13d, 13e, 13f, 13g, 13h, 13i, 13j, 13k, 13m, 13n, 13p, 13q, 131d, 131e, 131f, 131g, 131h, 131i, 131j, 131k, 131m, 131n, 131p, 131q) of the body (13, 131), wherein the spindle unit comprises: a second spring configured to bias the spindle unit upwardly; a pin and a first seat disc, wherein the first seat disc is configured to contact the pin, and wherein the plurality of ports (13a, 13b, 13c, 131a, 131b, 131c) comprise a first port (13a, 131a), a second port (13b, 131b), and a third port (13c, 131c); a second seat disc and a seat, wherein the pin is inserted into the second seat disc, wherein the second spring is received by the second seat disc to capture the second spring between the second seat disc and the body (13, 131); a guide threaded into the body (13, 131) and bearing on the first seat disc to longitudinally align the first seat disc along the longitudinal axis of the body (13, 131); and a seat screw threaded into the body (13, 131) and inwardly bearing on the pin, wherein the seat screw and the pin define a fluid passage in fluid communication with the second port (13b, 131b). a body (13, 131) that is integrally formed and defines a plurality of ports (13a, 13b, 13c, 131a, 131b, 131c), and defining a plurality of voids (13d, 13e, 13f, 13g, 13h, 13i, 13j, 13k, 13m, 13n, 13p, 13q, 131d, 131e, 131f, 131g, 131h, 131i, 131j, 131k, 131m, 131n, 131p, 131q), wherein the plurality of voids (13d, 13e, 13f, 13g, 13h, 13i, 13j, 13k, 13m, 13n, 13p, 13q, 131d, 131e, 131f, 131g, 131h, 131i, 131j, 131k, 131m, 131n, 131p, 131q) include cylindrical voids (13e, 13g, 13h, 13j, 13k, 13m, 131e, 131g, 131h, 131j, 131k, 131m) that have a central axis parallel to and collinear with a longitudinal axis of the body (13, 131); a bonnet secured to the body (13, 131) and defining a bonnet void; a diaphragm compressed between the bonnet and the body (13, 131); a first spring disposed in the bonnet void and configured to bias the diaphragm in a downward direction; and a spindle unit confined in the plurality of voids (13d, 13e, 13f, 13g, 13h, 13i, 13j, 13k, 13m, 13n, 13p, 13q, 131d, 131e, 131f, 131g, 131h, 131i, 131j, 131k, 131m, 131n, 131p, 131q) of the body (13, 131), wherein the spindle unit comprises: a second spring configured to bias the spindle unit upwardly; a pin and a first seat disc, wherein the first seat disc is configured to contact the pin, and wherein the plurality of ports (13a, 13b, 13c, 131a, 131b, 131c) comprise a first port (13a, 131a), a second port (13b, 131b), and a third port (13c, 131c); a second seat disc and a seat, wherein the pin is inserted into the second seat disc, wherein the second spring is received by the second seat disc to capture the second spring between the second seat disc and the body (13, 131); a guide threaded into the body (13, 131) and bearing on the first seat disc to longitudinally align the first seat disc along the longitudinal axis of the body (13, 131); and a seat screw threaded into the body (13, 131) and inwardly bearing on the pin, wherein the seat screw and the pin define a fluid passage in fluid communication with the second port (13b, 131b). a second spring configured to bias the spindle unit upwardly; a pin and a first seat disc, wherein the first seat disc is configured to contact the pin, and wherein the plurality of ports (13a, 13b, 13c, 131a, 131b, 131c) comprise a first port (13a, 131a), a second port (13b, 131b), and a third port (13c, 131c); a second seat disc and a seat, wherein the pin is inserted into the second seat disc, wherein the second spring is received by the second seat disc to capture the second spring between the second seat disc and the body (13, 131); a guide threaded into the body (13, 131) and bearing on the first seat disc to longitudinally align the first seat disc along the longitudinal axis of the body (13, 131); and a seat screw threaded into the body (13, 131) and inwardly bearing on the pin, wherein the seat screw and the pin define a fluid passage in fluid communication with the second port (13b, 131b).