Valves DBDS type are pressure direct command relief valves. Their fun- ction is to limit the pressure of a hydraulic system. The calibration of the system pressure is carried out continuously through the calibration de- vice, which, by the spring, pushes the wedge against the seat.
The P channel is connected to the pressure line of the system, entering the valve, and acts on the active area of the wedge (or of the ball for the DBDS 10 at 630 bar).
When the pressure in channel P exceeds the value set on the spring, the wedge or the ball raises in contrast to the spring. The fluid now flows from the channel P to the channel T. The stroke of the wedge is limited by a pin in the damping chamber.
To obtain a good resolution of the pressure setting from 0 to 400 (630) bar, this has been divided into 7 pressure ranges. Each range has a spe- cific spring for adjusting a maximum working pressure.
MAX OPERATING PRESSURE (PS): sizes 6, 20: 400 bar size 10: 630 bar size 30: 315 bar
PRESSURE SETTING (P): (upon request)
sizes 6, 20: 6 ÷ 400 bar
NOMINAL SIZE: 6, 10, 20, 30
LIFT: 2 mm
WORKING TEMPERATURE: -20 ÷ +150 °C
REPETIBILITY: ± 3% of P
CALIBRATION ERROR: 3%
OVERPRESSURE BY FULL FLOW: 10% of P
BLOW DOWN: 10% of P
FLUID VISCOSITY RANGE: 10 ÷ 400 cSt
RECOMMENDED VISCOSITY: 36 cSt
FLUID CONTAMINATION DEGREE:
class 20/18/15 according to ISO 4406/99
BODY MATERIAL: – phosphated carbon steel or galvanized carbon steel in compliance with Directive 2002/95/EC (RoHS) to
resist to corrosion.
– stainless steel (only DBDS 10 K)
SEALING MATERIAL: – P = Nitrile rubber (NBR) – V = Fluorocarbon (FKM)
CONNECTIONS: see Table 9.1d FLOW RATE: see Table 9.1d WEIGHT: see Table 9.1d