Hydraulic Fittings

Hydraulic fittings form part of a hydraulic system which connects hoses, pipes and tubes. There are various fittings which are used to connect the system together and help the hydraulic fluid to flow through. Hydraulic fittings, or hose fittings, are used to connect hydraulic hoses and pipes to other components such as valves and pumps.

Hydraulic fittings will usually have a male and/or female connection which join to other components. The connections are usually threaded and there are several thread standards available, such as JIC, BSP and BSPP. BSP male threads will seal with BSP female threads, for example. Popular materials include plastic, brass and stainless steel fittings.

Types of hydraulic fittings:

Plugs
Adapters
Couplings
Unions
Reducers
Elbows

How are hydraulic fittings attached?

There are several methods used to attach a hydraulic fitting. Examples include:

Compression fittings provide water tight connections by using pressure to seal the connection. They usually use a compression nut which, when tightened, removes space between the ferrule and the pipe.
Threaded fittings have screw threads on both sides of the connection. They accept connections with compatible threads and screw together for a secure connection. Not all threads provide a tight seal and may benefit from additional coatings or seals.
Crimped fittings require crimping of the hose to the fitting. You may require a crimping tool to achieve this.

Thread Types

Hydraulics machines are used all across the world and there are many components used in each system. Thread types are used to help make parts easily identifiable and easy to maintain and replace. Some examples of thread standards include:

NPT stands for National Pipe Thread where the threads are at a 60° angle. There is also NPT (National Pipe Taper) and NPS (National Pipe Straight).
BSP fittings stands for British Standard Pipe where the angle of the threads is 55°. This standard includes BSPT (British Standard Pipe Taper) and BSPP (British Standard Parallel Pipe).
Metric threads are specified by their diameter and pitch in millimetres (mm).