Hydraulic valves
Items are being added
KIT is adding items to this category. If you need a specific part, please send a quote request.
Frequently asked questions
What do valve sizes NG6, NG10, CETOP 3 and CETOP 5 mean?
These are mounting interface sizes to ISO 4401: NG6 corresponds to CETOP 3 (D03) and NG10 to CETOP 5 (D05). Valves of the same interface size from different makers share port and bolt hole positions. Larger sizes allow higher flow.
What does 4/3 mean on a directional valve?
4/3 means four ports (P, T, A, B) and three positions. The centre position comes in several forms, such as all ports closed, P to T for pump unloading, or A and B to T for a floating cylinder. A replacement must have the same centre type or the circuit will behave differently.
What do I need to know to replace a solenoid coil?
Voltage and current type (24 VDC, 220 VAC and so on), power, armature tube bore, coil length and connector type (for example DIN 43650). An AC coil energised with a stuck armature burns out quickly because current stays high. A coil of different voltage, even with the same size, will fail to shift the valve or burn out.
How should a relief valve be set safely?
The main relief valve is usually set about 10 to 15 % above working pressure so it does not bypass continuously in normal running. The setting must not exceed the lowest pressure rating of any component in the circuit. Set it with a gauge at the pump port, not by feel.
If a valve does not shift or sticks, is the valve faulty?
In most cases contamination is jamming the spool, rather than a failed valve. Check filtration and oil condition before replacing the valve, or the new one will stick too. Also check the actual voltage at the coil and the pilot pressure for pilot operated valves.
How should the mounting face for a subplate valve be prepared?
The mounting face must be flat, clean and free of scratches crossing the O-ring seats, with a port pattern to ISO 4401 for the valve size. Fit new O-rings every time the valve is removed and tighten the mounting bolts evenly to the specified torque. Uneven or excessive torque can distort the valve body and make the spool stick.
How clean must oil be for proportional and servo valves?
Proportional and especially servo valves have very small spool clearances, so they need far cleaner oil than on/off valves. Typical targets are around ISO 4406 code 16/14/11 or better, depending on the valve maker. A non-bypass high pressure filter should be fitted directly upstream of these valves.
How do I identify a replacement valve when the maker's code is gone?
Read the hydraulic symbol on the label or circuit drawing to find the number of ports, positions, the centre spool type and the actuation method. Measure the mounting pattern size and note the coil voltage and connector type. For line mounted or cartridge valves, the cavity size and thread type are also needed.
