Types of Hydraulic Hoses

Types of Hydraulic Hoses

Hydraulic Hoses

Different Types of Hydraulic Hoses

Hydraulic Hoses or Systems are everywhere, you just need to know where to look. If you see orange construction barrels, then you’re also looking at equipment littered with hydraulic systems. Zero-turn lawn mower? Yep. Garbage truck? Yes, again. Brakes on your car, the tilt on your outboard motor, in a manufacturing plant… they are everywhere. 

Hydraulic hoses or systems use pressurized hydraulic fluid to output work in a mechanical system. Let’s go over some quick basics. Hydraulic fluid is an oil or water based incompressible fluid. Since it is incompressible, it can efficiently transfer energy from a pump and send it to a motor or cylinder. To describe what a hydraulic system is, let’s talk about the most simple one: a log splitter. A pump pulls fluid from the reservoir through a return line and pressurizes it. The pressurized fluid is sent through a 2-wire hose and acts on a cylinder with a wedge, pushing on a log until it splits. As the piston retracts, the cylinder pushes the fluid back through a return hose into the reservoir to cool and get ready for the next cycle. This system—reservoir, pump, cylinder and hose—is the hydraulic system.

Hydraulic Hoses

Hydraulic System

Knowing a few details (refer to our Stamped article) about your system will help you decide what hose is right. Choosing a hydraulic hose is not that complicated once you’ve begun to understand the various options and why they exist.

On the one hand, there are a ton of hydraulic hose specs made by any one manufacturer. Heck, there are 19 SAE 100R specs and a handful of European EN specs. On the other, it’s really pretty simple. You’ve essentially got three options: rubber with metal wires, thermoplastic with textile reinforcement, or Teflon with stainless braid. There are a few other application specific specs out there, and we’ll talk about them in a bit, but, really, those are your three options. After you know which you need, the rest kind of sorts itself out.

Before we get started, there are some general things you need to know. First, hydraulic hose part numbers indicate inside diameter using a system of 1/16ths. For instance, -04 is ¼” inside diameter, or I.D. (4/16=1/4), and -12 is ¾” (12/16=¾) and so on. So, a part number like H28006 is hose spec H280 and size 06, or ⅜” I.D.

Next, hydraulic hose is usually rated based on a 4:1 safety factor. This means 3,000-psi hose bursts at 12,000 psi or more. Exceptions include jack hose which often has a 2:1 safety factor, because it is a static and low stress application. Ask our Hose Pros if you’re concerned about safety factor.

The general construction of a hydraulic hose is tube, reinforcement, and cover. The tube is the inside of the hose that conveys the hydraulic fluid. Then, there is the reinforcement; this provides the strength and holds the pressure. Last is the cover. The cover’s job is to protect the reinforcement from abrasion and corrosion.

Hydraulic Hoses

Construction Types

There are three main construction types for the pressure side of a hydraulic system and one for the return side. Hoses for the pressure side of your system will usually be made of rubber, thermoplastic, or Teflon.

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Rubber

Rubber hydraulic hoses are usually made of nitrile rubber since it’s compatible with most hydraulic fluids. Rubber hoses can either have textile braid for lower pressure applications under 1,000 psi, or high tensile steel wire for pressures up to 7,000 psi and beyond. The wire reinforced variety is the most common. Constructions range from one layer up to six layers of reinforcement.

Hydraulic Hoses - hose assembly
  • 1 Wire Braid – Less common than 2-wire hose. Used in lower pressure hydraulic systems.
Hydraulic Hoses - hose assembly
  • 2 Wire Braid – Less common than 2-wire hose. Used in lower pressure hydraulic systems.
Hydraulic Hoses - hose assembly
  • 4 Wire SpiralTypically used in heavy equipment requiring very high pressure (4,000-6,000 psi). Good at handling impulse.
Hydraulic Hoses
  • 6 Wire Spiral – Usually reserved for large diameter and ultra-high pressure (up to 7,000 psi)

Covers are usually made of an engineered rubber good at withstanding the elements and abrasion. Some manufacturers produce hoses with especially tough covers for applications requiring extreme abrasion protection; these might have UHMW coatings to withstand aggressive abrasion and impact. If you want to see hydraulic hose with tough covers cutting down huge trees in seconds, and you have a few minutes to waste on clickbait, you will love this video, especially the machine at 7:30: 

Some specialty applications for rubber hydraulic hoses include designs for high temperature (300°F+) and low temperature (-70°F).

Thermoplastic

This construction is typically made of a nylon tube, synthetic fiber reinforcement, and a polyurethane cover. Thermoplastic hose is often used in general hydraulics, material handling, forklifts, and near electrical systems. It can handle pressures similar to 1- and 2-wire hoses but be installed in applications where a rubber hose with wire reinforcement would not work. The polyurethane cover performs very well when subjected to the abrasion of a sheave on a forklift. In situations where electricity is a concern, like in a bucket lift for repairing power lines, non-conductive, thermoplastic hose is perfect.

Hydraulic Hoses

Teflon or PTFE:

Made with a Teflon tube and stainless braid reinforcement, it does not require a cover because the stainless braid will not corrode under normal circumstances. Teflon hose is used in applications that require corrosion resistance, chemical compatibility, or where high temperature is a concern. It carries a 450°F rating.

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Some things to keep in mind when specifying Teflon hose concern size and bend radius. The size is usually 1/16” smaller than the part number indicates. For instance, -04 hose is 3/16” and -06 is 5/16”. So, just because your part number ends in 04 does not mean the hose is ¼”. This is true for all sizes. Regarding bend radius, remember that Teflon hose is a hard-plastic tube covered in braid. If you bend the hard-plastic tube until it kinks, you’ve now ruined your hose and created a weak spot. Be careful when routing in tight spaces.

Return – Hydraulic Hoses

Return line is a hydraulic hose that can handle suction and is returning the hydraulic fluid back to the beginning of the system. This style of hose is usually a rubber tube and cover with textile braid for positive pressure and a helical wire to allow for suction.

Truck Hose – Hydraulic Hoses

Truck hose is its own special category within the hydraulic hose family. SAE 100R5 defines it as a fabric cover, 1-wire hose used on many systems in on-highway vehicles. Like Teflon hose, truck hose sizing does not follow the standard 1/16th approach used by standard hydraulic hose. The actual hose ID is anywhere from a 1/16” to ⅛” smaller depending on size. Again, call the Hose Pros at TCH, and we’ll help you understand 100R5 hose.

This covers most of the basics of hydraulic hoses. If you ever need to dig deeper and get into the nitty gritty call one of our Hose Pros at TCH and we’ll be happy to help.

TCH Industries

We. Are. Hosers.

Our focus and obsession is the distribution and fabrication of hose for industry and hose related products. Founded nearly 40 years ago, we are proudly owned and operated by the same family. Our manufacturing partners are some of the biggest and best names: Eaton, Parker, Dixon Valve, Hose Master, Brennen, Hannay Reels, and many others.

In short, we are a customer-centric hose company filled with happy professionals who can help you meet all your hose related needs. If you have any questions, please reach out to us by filling out the form below!

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Understanding Foreign Threads in the Hydraulic Industry

Understanding Foreign Threads in the Hydraulic Industry

Understanding Foreign Threads In The Hydraulic Industry

In an ever-changing world, it is hard to ignore the increasing amount of foreign threaded connections in the hydraulic industry. Whether it is in a port connection, to a hydraulic hose, even lubrication and grease fittings, they seem to be in all areas of a hydraulic application. Understanding foreign threaded connections can be very cumbersome, and confusing! But being able to understand, and more importantly identify foreign threads can make the difference on whether a customer purchases from you again or goes to the competition.

With the increased amount of goods purchased from over-seas manufacturers, it only makes sense that those goods will have foreign threaded connections. Essentially, there are only three countries that still use the Imperial System; The United States of America, Liberia, and Myanmar (formerly known as Burma). So, it’s no wonder why foreign threads are more prevalent than ever in the hydraulic industry. Here is a list of the most common Foreign threads in the Hydraulic Industry.

British Threads

The two types of British Threads are, Parallel (BSPP) and Tapered (BSPT). British Parallel threads are commonly referred to as a “G” thread, whereas British Tapered threads are referred to as “R” thread. They are measured in Nominal Sizes, and the threads are measured in Threads per Inch.

There are three sealing methods to a BSPP thread. This thread can seal using the BS 5200 60° Cone-Seat, which is like how a NPSM thread will seal, with an external Gasket, or the ISO 1179 O-Ring. These gaskets can include Bonded Seals, O-Ring and Washer combination, and Elastomeric Seals. The O-Ring Only Style is exclusive and will only seal with the correct size O-Ring, like the SAE J514 Straight Thread O-Ring Boss.

The British Tapered threads are only intended to seal on the flanks of the threads, like how a NPT thread seals, and are generally seen on lower pressure, or schedule pipe, applications.

Metric (DIN) Threads

There are also two styles of Metric Threads, Parallel or Tapered. Metric threads are measured, in millimeters, on the outside diameter and pitch of the threads. Generally, there are 3 thread pitches in metric fittings, pertaining to the hydraulic industry; 1.0, 1.5, and 2.0.

Just like the British Parallel threads, Metric Parallel threads can seal in one of three ways. Either, it can seal on the 24° Tube Seat, like an Ermeto® fitting, it can seal with an external gasket, or with the ISO 6149 O-Ring. The external gaskets are alike to the British Parallel style Bonded Seals, O-Ring and Washer combination, and Elastomeric Seals, ignoring the true size of the seal. The ISO 6149 O-Ring Only style is exclusive and will only seal using the correct O-Ring, like the SAE O-Ring Boss style previously explained.

Metric Tapered threads are generally seen in low pressure, and lubrication applications. They are intended to seal on the flanks of the threads, like NPT threads.

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Japanese (JIS) Threads

Japanese threads, or JIS, are easy to understand. They are nominally sized, and the threads are measured in Threads per Inch. JIS threads are the exact same size, pitch, and thread count as British threads. The only difference is that JIS has a 30° outward flare, similar to the 37° flare that we see on JIC fittings. There are more Japanese threads that exist in hydraulic systems, but to keep things as “easy” as possible, we will not go over those at this point.

Komatsu Threads

If this isn’t confusing enough, Komatsu threads tie in Metric thread pitch along with the JIS 30° flare. Komatsu threads are only ever used on Komatsu made machinery. Which is why when identifying threads, it never hurts to ask what kind of machine that the thread originates from.

TCH Industries: Hose, Fitting, & Sealing Experts

The highly trained sales staff at TCH Industries has been dealing with foreign threads for over three and a half decades. By partnering with world-class suppliers of fittings and adapters of every type, TCH has developed a top reputation for quality, reliability, exceptional service, and professionalism.

If you wish to receive a quote from TCH Industries for foreign accessories, please complete the easy-to-use online form that requests information about your needs in a simple questionnaire.

Best yet, for easy-to-understand answers from the hose and fitting pros at TCH, the solution is to visit in person the TCH Hose Center at 2307 East Aurora Road, Twinsburg OH, only 25 miles from the heart of Cleveland.

Identifying the Right Hydraulic Hose for Your Application

Hydraulic hoses must be durable and long-lasting enough to handle the needs of the particular function. Hydraulic hoses, unlike many other industrial hoses, need substantial reinforcement to endure the significant pressures that are necessary to perform their job. Reinforcing support can come in many forms depending on the levels of pressure, materials, and other factors that the hose will be required to withstand.

Consider STAMPED When Selecting Hydraulic Hoses

When determining which hydraulic hoses and fittings will be right for your situation, TCH Industries of Twinsburg, Ohio, suggests considering the acronym “STAMPED.” Seven questions cued by each letter will help identify which hydraulic hose is right for your situation. These are:

  • S: Size and diameter of the hose. Not only does this refer to the internal diameter of the hose but also to the required length from port to port.
  • T: Temperature refers to the maximum and minimum temperatures that the hose will withstand during all parts of the process.
  • A: Applications refers to the actual use of the hose and equipment. Will this be for industrial use or injection molding, for example.
  • M: Media refers to the liquid, gas, or solid that will be conveyed. Different medias require different levels of strength to accommodate what will be moving within.
  • P: Pressure is a critical variable in hydraulics. Pressure is the force that moves and lifts, so factoring the degree of pressure that the hose will need to withstand is essential.
  • E: Ends of the hose will be determined by where the hose will connect. The origination and destination ports may be different so the assembly might require different connecting hardware.
  • D: Delivery dates may be requested. These may depend on testing, certification requirements and, perhaps, custom production times.

Dealing with High Pressure

Hydraulic hoses, more than any other, are expected to withstand higher-than-normal pressure while in full operation. As a result, added reinforcement becomes mandatory.

TCH Industries offers hydraulic hoses that can withstand up to 10,000 psi, working pressure, as well as other hoses, fittings, and accessories for low and medium pressure scenarios.

The type and degree of reinforcement are calculated by the working pressure of the hydraulic system. As the pressure increases, the PSI rating of the hose must increase as well.

Most hydraulic hose reinforcement material may be one of three types, although combinations of these are often used to bolster the pressure capacity. These materials are:

  • Braided synthetic textiles, wire, and other materials set in a crisscross, overlapping pattern that allows for flexibility and maximum strength.
  • Spiral Wrapping with wire, textiles, synthetic materials consisting of parallel, rather than overlapping reinforcement. This pattern strengthens the hose while allowing for lower flexibility.
  • Helical coil (a helix pattern) strengthens the hose to prevent it from collapsing inside when suction or a vacuum is applied. The coil is often used in conjunction with the braided textile reinforcement to manage both high and low-pressure situations.

Check with TCH Industries

For questions about any hydraulic or industrial hose applications, check out the TCH Industries website. For the past three decades, TCH Industries has helped many manufacturers, construction businesses, petrochemical companies, agricultural concerns, food processors, brewers, and others to solve their hydraulic and industrial hose requirements.

As members of the National Association of Hose and Accessories Distribution, the TCH employees adhere to ISO 9001-2015 Standards and possess the engineering expertise for any job.

If you should be in the Northern Ohio Region, stop by the TCH Hose Center at 2307 East Aurora Road, Twinsburg, Ohio, to discuss your needs.

Alternatively, phone the professionals at TCH Industries at +1-330-487-5155.

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