Description of hydraulic fittings standards II
In Japan, there are two types of pipefittings commonly used
(1) AllKomatsu units use fittings with a 30°taper seat and metric fine thread. All flanges are type 61 or 62 (except -10*). (2) Most other Japanese equipment uses fittings with 30°taper seat and British standard straight thread, commonly known as JIS(Japanese industrial standard) fittings. These fittings are not interchangeable with inch fittings because their cones are in opposite directions. All flanges are type 61 or 62 (except -10*).
Japanese 30°taper Angle straight thread
Description: Japanese 30°taper Angle external thread joint can only be matched with Japanese 30°taper Angle internal thread. Both internal and external threads are straight threads with 30°taper seat. The seal is formed at the 30°cone seat. The threads on 30°taper Angle joints made in Japan conform to JIS B 0202 standard and are the same as BSPP threads. Both the British and Japanese fittings have a 30°cone seat, but they are not interchangeable because the British cone seat is opposite to the Japanese cone seat.
Japanese 30°taper pipe threads
Description: Japanese taper pipefittings and BSPT(taper thread)fittings are exactly the same, and completely interchangeable. The Japanesefittings does not have a 30°taper Angle, so it cannot be fitted with BSPP internal threads. This thread conforms to JIS B 0203 standard and is the same as BSPT thread. The seal of the Japanese taper pipe threadedfittings is formed at the thread.
Loose 30°taper straight thread
Description: Komatsu type 30°conical Angle straight thread joint and Japan 30°conical Angle straight threadfittings except for the difference in thread, other aspects are completely the same. Small loosefittings adopt metric fine thread, which conforms to JIS B 0207 standard. The loosefittings is sealed at its 30°cone Angle.
Note: Loose flangehose fittings is similar to SAE 61 flange joint and is completely interchangeable. The o-ring sizes of various flanges are different. When replacing loose flanges with SAE-shaped flanges, always use SAE-shaped O-rings.