In a $6 billion dollar industry, it can be tough to know which of the many hose and fittings options are right for your system. This task of choosing gets even more daunting knowing that choosing wrong is one of the most common reasons for hose and fittings failure.
What you need is a guide to help you narrow down your options. This not only ensures that your system runs efficiently with the right parts but also reduces the occurrence of hose or fitting failure.
Failures in your hoses or fittings result in a huge mess of hydraulic fluid that you now need to clean up. It can also present a safety hazard to those in the vicinity working.
Use this guide to help get you started in selecting the right components for your hydraulic system.
What Are a Hydraulic Hose and Fittings
These hoses are not your typical hose. They transport hydraulic fluid around your industrial machinery components.
You will typically find that they are a flexible material made of several layers to provide strength. These hoses are then connected with fittings.
The fittings are made out of steel so they can withstand high-pressure points. They also have fittings around the connection point that you can crimp. This will ensure a leak-free fit.
How to Pick a Hydraulic Hose
Picking the right hydraulic hose comes down to a balance of cost, effectiveness, and need. Do you spend more up front to make sure you get exactly what you need?
Or do you save up front installing whatever you have laying around but may not be the right hose? Sure it may seem like an obvious choice to spend less up front and get going again. However, this may not actually be the wisest of choices.
Look for hoses that have gone through testing by the manufacturer. Reputable companies will have strict testing procedures to ensure their products perform as expected.
Here are some of the tests that you should look for:
- standard operating pressure
- burst test
- impulse life
These tests push the hose beyond the standard operating conditions. This ensures that it meets safety standards and can withstand anything you put it through.
Once the hose goes through testing, you can depend on the manufacturer to give it an accurate pressure rating. You want to choose a hose that has a maximum working pressure that is above what your system’s working pressure is.
That way your hose will have no problem handling any temporary surge in pressure through the system.
You need to consider the inside diameter of the hose. Choose a hose that is too small and it restricts the flow. Now your linear velocity is too high which means you have too much friction.
The more friction you have, the more heat you have. These are all bad things you won’t want for your system.
You should be able to look at a manufacturer’s nomograph for determining the proper diameter for your length of hose.
Don’t try to skimp on the hose length. You need to have enough slack in the hose to accommodate for bending and flexing while the machine operates.
You need to also account for shrinkage under pressure. Just don’t add too much slack or we are back to the friction issue we talked about under diameter.
When picking the material for your hose you need to think about the operating temperature, possible abrasion, and weight. For example, if your hose it going on a mobile machine, the weight will be an important factor. In this case, you’ll want to consider a thermoplastic hose.
If your hose it going somewhere that is especially hot, rubber might not be the wisest of choices. If size is an issue then rubber might be a great choice. Thanks to advancements in technology these hoses have a thinner outer wall while still maintaining high-pressure strengths.
If you do decide to use a rubber hose, make sure you check the manufacturer date. These hoses have a shelf life of 10 years tops.
How to Pick Hydraulic Fittings
When it comes to picking the right fittings, it is vital that you pair it correctly with your hose. You need the two parts to work together or both will be compromised.
There are 7 most common types of connections when it comes to fittings.
- JIC 37⁰ Flares
- NPT Pipe Threads
- Four-Bolt Flange
- O-Ring Boss
- DIN Metric 24⁰ Bite Type
- Inch Compression
- O-Ring Face Seals
There are two common ways of attaching the fitting to the hose. They are a crimp fitting and a field attachable fitting.
The crimp fitting does exactly as the name implies. A machine crimps the fitting to the hose. A field attachable fitting is also called a reusable fitting. This will be a socket and nipple type setup.
If you need a fitting with the most amount of versatility then consider a JIC fitting. These fittings let you connect to the most amount of other types and sizes of fittings.
The standard fittings for decades have been the JIC and NPT. So these are going to be the ones you most readily find. They are also going to have the most variety when it comes to volume.
The pressure rating of your fittings needs to match the hose and the rest of your system. If it is lower, you just effectively reduced your maximum pressure for the whole system.
If you ignore this, you risk the fitting popping off under the pressure.
Use the STAMP acronym when determining if your chosen fitting is meant for your intended application:
While a fitting may work perfectly for one application, it could be totally unsuitable for another.
You need fittings that are going to last and withstand use. NPT pipe threads have always been a popular choice because you can fix leaks and really tighten them down.
The problem is this makes them less reliable because they become prone to cracking. For greater reliability look to mated sealing surfaces.
These can be found in O-ring face seal fittings. They reduce the risk of shock from over torquing.
Outfit Your system
When it comes to buying hoses and fittings for your existing or new system, you want to make sure you buy the right components to withstand the pressure and heat created. It vital for safety standards that you consider the pressure tolerance of the hose and fittings.
Start shopping today for your system’s hose and fittings.