What You Need to Know About High Pressure Hose Fittings

Recommendations for Selecting Hydraulic Hose Fittings

Depending on the flow rate and pressure of a given hydraulic system, the selection of the appropriate hydraulic fitting size and the line size is one of the keys to ensuring the efficiency and reliability of the hydraulic system.

The proper selection of hydraulic fitting specifications and line sizes for different parts of the hydraulic system determines whether the system has the best combination of cost and efficiency.

Too small a hydraulic fitting and line flow diameter can lead to high flow rates, which can have many damaging effects on the system. In pressure lines, it causes high frictional losses and turbulent flow resulting in large pressure drops and heat generation. High heat will accelerate the wear of the connecting parts and the aging of the seals and hoses, which will eventually be reflected in the reduced working life of the system components. High heat also leads to energy loss, which reduces the efficiency of the system. Excessive hydraulic coupling and line flow diameters increase system costs. Therefore, the ideal selection of hydraulic fitting specifications and piping size is very critical.

In the piping design of the hydraulic system, the following flow rates are generally recommended.

Working line: <8m/s

Oil return line: <4m/s

Oil suction line: <1.2m/s

If you are still not sure how to choose the right hydraulic fittings and pipe size, we suggest you contact us directly. XCD is a wholesale supplier of hydraulic fittings, supplying hydraulic fittings and adapters all year round, and has professional technical engineers who can choose the most suitable hydraulic fittings and pipe size for you according to your project requirements.

Maintenance of High Pressure Hose Fittings

In the hydraulic system, both metal pipe joints and flexible pipe joints have the problem of easy leakage. In the case of tube fittings, most of the leaks are caused by large external forces or impacts on the pipe, which may loosen the ferrule or deform the tube end surface. At the same time, the external force of the pipe should be eliminated. For flared pipe joints, most of them are caused by excessive flare, poor quality, or repeated disassembly, resulting in flare deformation or cracks that cause leakage, at which time the front end can be cut off and re-flared.

If the male and female cone top pressure is used for sealing, the leakage is mostly due to the damage of the two cone surfaces, and the cone surface can be ground with abrasive sand. 

In some cases where the "о" ring is sealed by the end face or outside diameter, the leak is caused by the following reasons:

"о" shaped ring aging or deformation caused by leakage; 

"о" shaped ring assembly is not in place so that the two planes connected when the pressure is not flat or "о" shaped ring is cut to cause leakage;

"о" shaped ring is not compacted, the elastic deformation is not enough to cause leakage; 

"о" shaped ring stop groove is too deep and caused by leakage. 

In this regard, you need to choose the same outer diameter and thicker cross-section of the "о" ring, but also the sealing plane with the stop groove cutting or grinding process to reduce the depth of the stop groove so that the "о" ring has sufficient elastic deformation (compression should generally be in (between 0.35-0.65mm). 

For the use of oil-resistant rubber plate, wool felt, soft steel cardboard, combined sealing gasket or sealant leakage at the joint, no matter what material, first of all, the seal should be checked for damage, deformation, aging, and roughness too large, and then take appropriate measures.

Notes on High Pressure Hydraulic Hose Fittings

(1) The welding work of the pipe has been fully completed before acid cleaning.

(2) When disassembling, transporting, and pickling, be careful not to touch the pipeline, threads, and sealing surface, and use tape or plastic pipe to plug and seal.

(3) Clean the weld slag, spatter and varnish on the pipe before pickling.

(4) Each threaded part should be protected with acid-resistant materials such as plastic tape or rubber tape, or the threads should be coated with dry oil after degreasing and water washing before removing rust in acid to prevent acid erosion.

(5) When pickling, be careful not to make the matching marks of the pipe disappear or be blurred.