Primary pressure control valve Yoshitake GD-21

1. Most suitable as a drain valve for a pump in a closed circuit.
2. No leakage when closed thanks to the single-seat valve and plug.

Flow characteristics graph

(Example)
When selecting the nominal size of the differential pressure control valve at differential pressure (∆P), specific gravity and flow (V) 0.2 MPa, 1 (water) and 5.5 m3 / h, respectively, first draw down a vertical line from the value of the differential pressure (∆P) 0.2 MPa before the intersection (a) with the flow line (V) 5.5 m3 / h. Since this intersection point (a) lies between dimensions 25A and 32A, choose the larger of the two, 32A.
If the specific gravity is 0.7 under the same conditions, draw a vertical line down from the differential pressure (∆P) value of 0.2 MPa and find the intersection point (b) at specific gravity 1. Find the intersection point (c) at 0 specific gravity , 7 by drawing a horizontal line from point (b) to the intersection with the corresponding oblique line. Then find the point of intersection (d) with the flow line (V) of 5.5 m3 / h by drawing a vertical line downward from the point of intersection (c). Since this intersection point (d) lies between dimensions 20A and 25A, choose the larger of the two, 25A.
* Select GD-21 valve at specific gravity 1.

GD-21 Nominal sizing diagram (for air)