INTENSIFIER TYPES

 

The intensifier is the heart of the HP – pump. Its design and lay out is based on many years of experience in high pressure technology. Usually the hydraulic piston directly is connected with the two plungers. This is the standard design, which results in a very compact unit. For special application a stand off separates the hydraulic part from the high pressure part. This is important in order to absolutely avoid any mixing of the hydraulic oil with the liquid to be pumped at the high pressure end, or in case the temperature of the liquid to be pumped is higher then the maximum oil temperature allowed.
The main wear – off items are made from tungsten carbides or ceramics. Lifetime for these items  almost becomes unlimited.
All wetted parts of the high pressure system are fabricated from high strength, high alloy, and corrosion resistant special steel. In case of pumping untreated water or in case of extremely high loads, the high pressure parts are autofrettaged. This increases the life time and reduces the danger of stress corrosions. Pressures used for autofrettage can be as high as 1200 MPa.
All remaining parts made from carbon steels or tool steels are high grade surface protected or painted.
Although maintenance requirements are very low, the intensifiers are designed in order to ease disassembling and assembling.
A special design of the check valves allows replacing a check valve within a minute.
By preferring self energizing seal rings, it became possible to easy open and close the high pressure barrel in case a change of a seal system should be necessary.
Mainly three kinds of intensifier are available, depending on the working pressure. They differ in the design of the barrel and the check valves.
Up to a working pressure of 300 MPa the check valves are arranged in a T – piece. This is a commercially available one for smaller intensifiers and it is a tailor made T – piece for the larger ones. The check valves are arranged in an inlet and an outlet screw, which is screwed into the T – piece. A special short tube connects the T – piece with the open end of the barrel. HP – barrels of this pressure class have an inside thread on one side, to which the T – piece is connected.
For higher working pressures up to 500 MPa, the barrels are symmetrically. The barrel can be used either with the one or the other end fixed to the hydraulic cylinder. The check valves are screwed as a complete set into a special valve body. The valves are inclined. By this it is possible to arrange inlet and outlet bores in the valve body towards the barrel end with out crossing. The special design of the check valve avoids springs. A threaded joint connects the valve body with the barrel end.
For pressures above 500 MPa the threaded connections are replaced by stud bolts. The design of the check valves and the valve body is unchanged, but the valve body connects the barrel to the hydraulic cylinder with stud bolts. The barrel can be disassembled from the hydraulic cylinder with out removing the stud bolts. The valve sets are bolted to the one end of the valve body.