Hydraulic valve works

Hydraulic valve works
1) Industrial (also known as fixed equipment, which is relative to the walking mechanical terms) is generally 4-pass valve, that four main ports: pressure oil imports P, load ports A and B, leading to the tank back to the oil port T. The rest of the control port, load pressure LS port, drain port and so can not be calculated in a few pass inside.
2) Those who need the pilot to control the oil on the main stage of the elements, such as reusable hydraulic hose fittings, the pilot oil sources are present and how to deal with the issue back to the oil. This is the performance of hydraulic quick couplers technology flexibility, giving users stay out of the room according to the actual needs of the system for selection. Here:
X-- control oil inlet from the outside of the main system (called external control, if from P mouth, said internal)
Y-- control oil taken directly to tank port (called outside back (leaks), if returned to T port, said inner back (inside vent))
L-- valve leak within the oil tank alone brought back the oil port
3) Incidentally, processing pilot oil can be reasonably combined as required:
External control, outside back; external control, internal back; internal and external back; internal control, internal back.
4) Incidentally, for L mouth leaking oil, outside the pilot oil return, must lead directly back to the tank (or through the filter), should never be brought together to the main return oil tank T ports be brought back. This situation is even more sensitive in the ratio, the servo system.