Hydraulic Hose and Fittings Blog

The Stainless Steel Fittings Blog


August 23, 2013

Stainless Steel Tubing

Often there is need for a sturdy tubing that will not react to the substance it is carrying, while at the same time resisting corrosion. Food processing, auto engines, chemical plants, oil and gas transportation, and a host of other applications just begin to scratch the surface of applications that require a sturdy material to provide reliable tubing.


            Stainless steel tubing is often the material of choice, as it is known for it's resistance to corrosion, and has minimal reactivity to most chemicals. It is a little different from most other tubing, in that it is sized from the outer diameter rather than the inner, as is the case with most other materials.


            Stainless tubing also comes in two forms: Seamless, which is extruded under high heat to provide a stronger end product for high-pressure applications, and welded, which is made by rolling up a stainless steel sheet and welding to create the tube. Welded tubing is generally cheaper, but the weld line can be a fail point when pressurized.


            There are also two different grades of stainless steel that can be used in these tubes- 304 grade mixes the steel with 8% nickel and 18% chromium, and the 316 grade uses a blend of 16% chromium, 10% nickle and 2% molybdenum. The addition of molybdenum to the 316 grade raises the steel's resistance to chlorides and other chemical corrosives, which is a must when the tubing will be exposed to the harsh salts of coastal or marine applications. Because of it's more expensive composition, you can expect to pay slightly more for 316 grade, but it might save you a costly replacement or two. 


July 23, 2013

Stainless Fittings: Tube Fittings


Stainless fittings are used in multiple industries through the world.  Tube fittings are manufactured by multiple companies in North America, Europe and Asia.  The stainless tube fitting industry had its major start in the state of Ohio during the manufacturing boom of the early 20th century in America.  Stainless tube fittings were used to terminate tube ends using a system of ferrules and compression nuts.  The ferrule or ferrules slipped onto tubing after which a nut was brought down onto the ferrule and tube.


Once the nut was tightened, the ferrule compressed onto the tube and then threaded onto a fitting body to terminate the tube.  The stainless fittings that were used for terminating stainless tubing was in the shapes of straights, 45 degree connector, 90 degree elbows, tees and crosses.  Caps and plugs were also used with the plumbing drawings called out for them.  Stainless fittings that are used for tube applications are generally manufactured out of 316 stainless steel. 


Although Indian and Chinese companies have recently entered into the market in recent years, these fittings are predominately American and Korean (which have surpassed European manufacturers) made.  American companies such as Swagelok and Parker A-Lok as well as SSP and Tylok hold most of the market.  Korean manufacturers are growing strongly as their quality is easily equal to that of US and European manufacturers.


Korea based manufacturers of stainless fittings have a strong reputation for quality and workmanship.  This has been an outcome of the deep history of shipbuilding Korea has had for the past 40 years.  Stainless tube fittings are often used on ships, cranes, platforms and other equipment that is exposed to the harsh saltwater and corrosive chemical often found off shore.  As Korea has built an economy based on export, components such as tube fittings have to be of excellent quality to meet requirements of their customers globally.


Swagelok of Ohio is still the market mover in the industry and has a deep history of manufacturing as well as logistical expertise.  Their vendor managed inventory (VMI) programs are used throughout the world for manufacturers that want to keep inventory available and stock lean.  Swagelok is a privately held corporation that produces approximately $1,500,000,000 in revenues (US dollars) annually across three major manufacturing centers.  A distribution network of 200 corporate owned and dealer supply hoses keep Swagelok close to their customers.


The market for stainless fittings continues to grow annually.  Industries such as biotech, alternative energy, chemical processing, and the petroleum industry push the market ever upwards.  These industries cannot afford any leaks in their process and are willing to pay top dollar for stainless fittings that can assure them of clean efficient function for years to come.



June 3, 2013

Stainless Steel Manufacturing Processses

 

Stainless steel is machined in the very same way as most steel components.  The differences in process include heat treatment as well as the machine tools used to machine stainless versus carbon steel.  Stainless can be more abrasive due to the higher levels of alloys such as Moly and Chromium.  Nickel is also found in a high level in stainless fittings.  Take a look at the YouTube video below for stainless steel manufacturing processes.

http://www.youtube.com/watch?v=ClFrKJ4Z5x8


May 1, 2013

Stainless Steel hydraulic hose manufacturers see an increase in sales forecast

 

Stainless steel hydraulic hose is commonly used in corrosive environments throughout industries from offshore drilling to food/beverage preparation.  For the first time since 2007, manufacturers of stainless hydraulic hose have seen an larger than 25% quarter to quarter growth in the marketplace. 

 

 

April 1, 2013

Stainless steel compression tube fittings used in numerous industrial applications

 

Hydraulic applications: food/beverage, offshore, cryogenic, natural gas, and others use stainless steel tube fittings (also known as compression fittings) to join stainless steel tubing for many years.  Now these fittings are being incorporated into emerging energy markets such as bio diesel, biopetroleum, pharma, and nuclear energy.

Stainless steel fittings supplies single ferrule and double ferrule stainless steel compression tube fittings that work as equivalent to Swagelok fittings. These interchangeable fittings allow customers to install fittings that provide excellent service at great value versus Parker or Swagelok fittings.

 

March 1, 2013

Stainless Steel Fittings Adds Filtration options to our online store such as Air Sentry, CC Jensen and Magnum magnetic filtration.

 

You can now get a great selection on hydraulic oil filtration products online. Our represented companies are best in filtration products. They offer products that remove air contamination, "in oil" contamination and metal contamination to keep moving parts running cleaner and longer. Air Sentry provides a great selection of air breathers that remove solid and water contamination from system incoming air. These air desiccant filters carry a desiccant gel/pellets that absort water content from the air. Air Sentry air desiccant filter come in a variety of types depending on the application.

CC Jensen or CCJ filtration systems are offline hydraulic, gear and lubrication filter systems that remove existing solid contamination form oils. Theses filters have the ability to remove all unwanted solid contamination from a system within hours.

Magnum filters use a magnetic filter to remove all unwanted ferrous material from a system. The magnetic filters also remove large metal shavings that can be extremely harmful to a hydraulic pump.

 

 

February 1, 2013

British BSPP and BSPT Metric Fittings & Hydraulic Adapters

 

StainlessSteelfittings.com carries a full line of British BSPP (British Standard Pipe Parallel) and BSPT (British Standard Pipe Tapered) hydraulic fittings for our North American customers.

BSPP is British Standard Pipe that has a parallel (hence the last "P" in BSPP) thread line and seats directly into a cone. BSPT is British Standard Pipe Tapered (the "T" in BSPT) stands for tapered) and tapers a hydraulic connection in much the same was as does NPT or National Pipe Thread fittings.

Often BSPP and BSPT British fittings are found on equipment manufactured in England or in Europe. This is an older thread pattern that is over time being replaced by metric thread in Europe. However there are still a significant amount of manufacturers that still use British fittings thread. StainlessSteelFittings.com supplies a full line of British BSPP and BSPT fittings for their line of customers.

 

 

January 1, 2013

Custom Manufactured Hydraulic Hose Assemblies Made and Shipped Direct


StainlessSteelFittings.com manufactures custom hydraulic hose assemblies. Provide us with the hose type, size, and length, then tell us which hose ends you would prefer. We will build it and ship it direct to you and a significant discount over your local hose shop.

StainlessSteelFittings.com uses excellent Parker/Weatherhead equivalent hydraulic hose as well as US manufactured high quality hydraulic hose end fittings. Using our in-house hydraulic hose crimpers, we can produce hose up to 2" in diameter with bite to the wire hose end fittings. Contact us today with your specifications and we would be able to produce and ship your hose order within the same week. We can provide high abrasion hydraulic hose as well as standard hose for any application.

StainlessSteelFittings.com also supplies hydraulic fittings and adapters to work in parallel with your hydraulic hose assembly. We carry a large selection and have excellent stock to meet your needs.

 

 

December 11, 2012

Stainless Steel Fittings & Stainless Adapters for the Oil and Gas Industry

 

Stainless steel fittings have seen a major surge in usage due to high oil demand and production. Chemical processing and well as hydraulic equipment often will require stainless steel material for the fittings to last in harsh environments moving harsh chemicals.

In the global supply of stainless steel hydraulic fittings and adapters, there are not that many manufacturers that produce quality stainless steel products. Low cost countries have started to machine stainless fittings however often their quality is inferior as smaller details are overlooked. Thread and bore quality as well as inclusions in the metal may cause inconvenience to customers that require their stainless adapters to perform for years on end.

StainlessSteelFittings.com carries only the highest quality stainless fittings and adapters. StainlessSteelFittings.com also carries stainless steel hydraulic hose along with stainless steel hose end fittings. These components are qualified with many oil and gas customers across the globe and provide excellent value for the price.

 

 

November 1, 2012

Hydraulic Hose Manufacturers Consolidation


Recently Eaton Aeroquip acquired SEL Hydraulic Hose. SEL, based in Turkey, manufactured high quality hydraulic hose for the European and middle eastern markets and was well known for it's high quality hydraulic hose manufacturing. The quality was so high that Eaton Aeroquip had no issue in purchasing SEL and will soon start marketing the brand as it's own. With the premium brand mark up of course.

It seems this has become a habit in the hydraulic hose manufacturing industry. Smaller high quality companies grow over decades to offer excellent quality hydraulic hose and accessories. As soon as their products become a threat to the profit margins of larger companies, they are bought out and then consolidated into the fold.

There are still a few excellent independent hydraulic hose manufacturers left that still make excellent quality hose at a fraction of the cost compared to the larger manufacturers. StainlessSteelFittings.com specializes in carrying these high quality hydraulic hose brands that provide excellent value and matched quality to the larger brands.

 

 

October 3, 2012

Stainless Steel Hydraulic Fittings vs Carbon Steel Fittings


So, what's up with the huge price difference? Stainless fittings are basically used in areas where carbon steel corrodes too easily. Stainless Steel does not rust when exposed to water, which makes it ideal in the marine, food, chemical and food industries. Stainless steel fittings are typically also rated for higher pressures, which makes it great for high pressure hydraulic applications. Why the high price? Well that's due to the material cost but mainly due to the lower production volumes when stainless steel fittings are produced.

 

 

September 3, 2012

CC Jensen / CJC / CCJ Offline By-Pass Oil Filtration Systems

 

CC Jensen oil filtration systems and CC Jensen filters are designed to be by-pass offline oil filtration systems that do not affect the main components in an oil circuit. These filtration systems have their own pump and motor assembly that can run on 12V, 24V for DC and 110/240/480/600 V for AC. These filtration systems are build extremely robust and have been for over 50 years in Denmark. They are built to last the life of the equipment they are protecting and are found in many industries globally.

CC Jensen (also called CCJ and CJC) filtration systems are found on wind power, waste/recycling, oil/gas, mining/construction, marine, industrial equipment and storage tank applications. CC Jensen filters are the core technology behind the filtration theory of CCJ filtration systems.

These filters have the most carrying capacity of solid and liquid contamination by mass. The CCJ filters (also known as CJC filters) can carry multiple pounds of solid contamination and can remove gallons of water from oil circuits.

CC Jensen filters are often connected to oil reservoirs where they are most efficient in removing contamination down to the sub micron level. Contact Stainless Steel Fittings for a quote on CC Jensen by-pass filtration systems. We assist in system design and can offer on-site installation if required.

 

 

August 2, 2012

Hydraulic Quick Disconnects

 

Quick connects (also called quick disconnects and quick couplers) are an essential family of hydraulic components for hydraulic systems. Quick connects are used for hydraulic connections that require frequent hydraulic plumbing changes. These couplers are often found in the oil/gas industry where frequent rig moves require hydraulic lines to be disconnected before transport.

Quick disconnects have to be able to 1.) bear high pressure without premature release 2.) couple easily between male and female quick coupler adapter sets and 3.) endure hundreds if not thousands of connections without leaking. These requirements force hydraulic quick coupler manufactures to produce high quality quick connects to satisfy the customer's specifications.

Quick connects come in multiple styles and are often interchangeable between brands. ISO A, ISO B, Agricultural AG, Flushface, and General Purpose quick connects are available at StainlessSteelFittings.com. These can be purchased individually or in sets.

 

 

July 6, 2012

Hydraulic Crimpers for Hydraulic Hose Assemblies

 

Hydraulic crimpers for hydraulic hose come in two types. The first is an adjustable style with a dial in gauge that allows the user to dial in the final crimp diameter. In order to use these adjustable variable hydraulic crimpers, the user does need a die to bring the fitting close to the desired diameter. The second type is a fixed style of hydraulic crimper manufactured by companies such as Parker.

These type of fixed hydraulic crimpers only allow users to manufacture hose assemblies using the same brand of hydraulic components as the crimper itself. Manufacturers will often use this technique to supply their own brand of hydraulic hose and hose ends after a crimper is sold to a customer.

Adjustable hydraulic crimpers are gaining in popularity and are manufactured by a few large manufacturing companies. Included in this group is Customer Machining Services Inc. of Valparaiso, IN which manufactures the CustomCrimp brand of crimpers. CMS Inc manufactures both adjustable and fixed crimpers.

 

 

June 3, 2012

A Full Line of Stainless Steel Hydraulic Fittings

 

StainlessSteelFittings.com supplies a full line of stainless steel hydraulic fittings such as stainless steel pipe fittings, stainless steel JIC fittings, stainless steel NPSM pipe swivel fittings, stainless steel o ring boss ORB fittings, and stainless steel flare flareless compression fittings.

Stainless steel pipe fittings and adapters as well as the other stainless thread styles are often used in applications requiring sanitary or chemical protection for the fluid in the hydraulic system. Stainless steel pipe fittings can be found in food processing, beverage manufacturing, chemical manufacturing and fluid refining.

StainlessSteelFittings.com uses SS316 stainless steel which is a high strength material often used for manufacturing stainless industrial tools. Our stainless steel fittings are forged in one piece than machined to requirement specifications.

Stainless steel pipe fittings are growing in popularity and usage across the industry. Look to StainlessSteelFittings.com for your stainless steel fitting needs.

 

 

May 4, 2012

Hydraulic Hose Summary

 

Hydraulic hoses are used for high pressure fluid power applications on mobile and fixed machinery. StainlessSteelFittings.com carries an outstanding inventory of excellent quality hydraulic hose and fittings that are manufactured to the same specifications as brands such as Parker Hose, Gates Hose, Weatherhead, Eaton Aeroquip Hose, Goodyear, and other respected major manufacturers.

Our customers include the largest onshore and offshore oil & gas drilling contractors, mining/construction operators, waste/recycling fleets, power generation companies, as well as thousands of repair and maintenance professionals. Our hydraulic hoses are matched perfectly with our hydraulic hose fittings to provide superior performance and value.

 

 

February 3, 2012

Quick Connect / Disconnect Couplers

 

Quick Connects/Disconnect couplers are used to rapidly connect and disconnect hydraulic fluid lines with the minimal of spillage. Quick connects couplers are manufactured by multiple manufacturers and can be often interchanged. StainlessSteelFittings.com supplies the highest quality hydraulic quick connects/disconnect couplers such as flushface, ISO A, ISO B, wingnut, Ag, and Skid Steer quick couplers.

For more details and information on the Quick Connect/Disconnect Couplers below, be sure to click on "more info". If you need more information than what you see online, be sure to contact us.

 

 

January 13, 2012

More About Us, StainlessSteelFittings.com

http://www.StainlessSteelFittings.com/
Hydraulic Hose
Hydraulic Fitting
Hydraulic Tubing

StainlessSteelFittings.com supplies OEM equivalent, industrial grade hydraulic hose, hydraulic fittings, hydraulic tubing, steel adapters, quick connects and other hydraulic components directly from our manufacturing partners. We focus on maintaining the highest quality standard while providing excellent customer service to back our products.

Since our start in 2000 StainlessSteelFittings.com has grown steadily into one of the largest distributors of hydraulic hose, fitting and tubing components in North America. Our clients range from small shops to some of the largest Fortune 500 companies in the petroleum, mining, energy production, waste/recycling and agriculture industries.

We are passionate about our business and hope to have the privilege of serving you soon. When you have questions or need more information on hydraulic hose, hydraulic fittings, hydraulic tubing or any of our hydraulic supplies, please feel free to contact us at any time with your feedback and we will see you soon on StainlessSteelFittings.com!

 

 

December 13, 2011

Hydraulic Hose Sector Market Trends

 

The hydraulic hose and fitting sector continues it's upward growth after taking a hit in the down markets of 2007 and 2008. Industrial manufacturing followed by the boom in oil and gas production has lead this industry back on the path to profitability.

"Hydraulic hose and hydraulic fittings always lag behind a recovery," said Larry Jones, executive of a major hose manufacturer. "The Parker Hose, Eaton / Weatherhead, Aeroquip, Gates and Goodyear brands took hits but are now all starting to recover at a healthy pace" he added.

"It's important to note that the hydraulic hose market really is a robust industry," said Jeff Funk, VP of a Fluid Conveyance business. "It's an enabler." "As such, without hydraulic power, some industries couldn't even operate." He added "The hose industry will come out and continue to be a contributor to all other industries."

"The only ones that are that are doing very well are off-shore and very deep water drilling. Everybody else has to be affected some way," said the VP of sales for Hy-Flo Hydraulics Inc.

However, as the market for hydraulic fittings, hydraulic hose, and adapters starts to resume business as normal, many executives understand that to weather the downward trend, a company needs to stay healthy during the upwards trends. This involves all facets of a business and it's product portfolio.

StainlessSteelFittings.com stays healthy by always monitoring it's lead time to insure it has the stock it needs to serve its customers but not to over stock in case there is a turn. With fulfillment rates in the 98% range, it is clear this is a strategy that works.

 

 

November 10, 2011

Hydraulic Hose Suction Lines

 

Hydraulic Hose suction lines supply pumps with oil from their reservoirs. Hydraulic suction hoses are unique because they can go below the atmospheric pressure and if not constructed properly, the hose will collapse which will starve a pump for oil and will ultimately cause a pump failure. This is why it's not a good idea to replace suction lines with a higher pressure hose as the inner liner of a high pressure hose can collapse from exposure to a vacuum. Suction hydraulic hoses typically have coiled wires incorporated inside the tube in order to stiffen it and prevent collapse.

If a suction strainer is used and undersized for the flowrate, and a machine is older where the strainer may be partially plugged, the pump may generate high vacuum pressures. Another thing to determine is what suction line is large enough for the hose flow rate and length of hose run. The hydraulic fittings used in suction lines are also critical. As are other components such as hydraulic adapters, cam and groove hydraulic fittings, and hose guards. Some rules of thumb state that 90-degree fittings are equivalent to 6 feet of hydraulic hose when calculating a pressure drop across an assembly. The best way to verify that a suction hydraulic hose line is good is for an engineer to be responsible for building a machine that checks pressure drops in the suction line during hydraulic operations including cold weather. If t here are multiple pump failures on a machine, it could be the hydraulic suction line itself.

Contact a local hose supplier, as they should be able to provide pressure gages in order to check the lines. Another thing to inspect are the hydraulic fittings themselves. I've experienced 90-degree fittings not drilled properly, resulting in a much smaller hole than was intended, and creating, in effect, an unwanted orifice. The best way to create a 90-degree turn may be through a 90-degree hydraulic hose end fitting because the tube bend is usually gentler than a sharp corner hydraulic fitting.

However, sometimes the space is limited on a machine and you have to make due to the best you can. In this case, make a suction hydraulic hose and hydraulic fitting assembly as large as possible right into the pump and the reduced the size at the pump. The high-pressure line will typically run from the pump to the hydraulic valves and then to the motors and cylinders.

 

 

October 3, 2011

Hydraulic Hose System Design

 

Hydraulic hose must match the highest pressure capable in a hydraulic system, which is typically the pressure the pump provides. However, there can certainly be pressure increasing components in machines that can go much higher than the hydraulic relief or a pump pressure capacity, especially when a pressure intensifying cylinder is flow generated. Special attention must apply when designing systems with geared flow dividers because of this effect.

Hoses usually have a burst rating of 4 times the pressure rating so although a lower rated hose can work for a short time, they will fatigue and then fail in a shorter time. It's a good idea to then look at the failed hose to make sure it will match the hydraulic flow circuit pressure ratings. Sometimes people can simply make a hydraulic hose assembly from the wrong type of hose and won't realize it only until failure. This can happen even from the factory.

High pressure hydraulic lines for mobile equipment usually come in a few number of pressure ranges. There are exceptions to this, especially with hose manufacturers trying to crack into market share by offering different benefits to their customer. 6000 psi pressure rated hydraulic hose can be typically found on closed loop hydro-static circuits such as trackground drives and higher horsepower drives used on drillers, trenching equipment, etc.

Next, there is the 4000-psi hose that is used on some of the open loop piston pumping systems involved in manufacturing. The most common hydraulic hose found in industry is the 3000 psi rated hose, which is common with gear pumping circuits used in correlation with high pressure cylinders and gear motor systems. There are many hoses 1500 and lower psi ratings for the return lines and other special case applications. Most of these hydraulic hose lines are used to supply the valves and then return back to oil coolers, hydraulic filters, and the oil reservoir. If you wonder, why not use the highest pressure hydraulic hose on everything in an oil circuit; it's because of the higher cost.

 

 

September 8, 2011

Manufacturing Hydraulic Hose

 

Often, steel lines have advantages over hydraulic rubber hoses because of greater heat rejection, better abrasion resistance, fire resistance, and better pressure fatigue resistance. If there is a long distance run to on a machine, it can be a smart idea to install solid steel lines bent into shape for routing the hydraulic oil circuit.

Hydraulic hoses expand with every pressure cycle. These hoses usually have a crimped steel end also called a hydraulic fitting. Fatigue failure of a hydraulic hose will typically happen near the hose end as the rubber hose and the steel fitting hose end will expand at their different rates. The hydraulic hose end can also be susceptible to an incorrect crimp process if the crimping technician is not trained. Steel hydraulic lines are not going to be as flexible as hydraulic hose, so be careful to not preload any component that they are connected to when mounting the steel line to the machine.

During manufacturing, hydraulic hose is the last thing done to a machine when being built. When technicians and engineers are hurried and under work pressure to meet deadlines, it is the hydraulics and hydraulic hose that usually suffer. Overtime, after complaints come back in from the customer or if you have a good technician, they can route the hydraulic hoses and fittings to give the best service of the components.

In addition, it is important to note that careful attention should be made as to how hydraulic hoses will lay while in service. For example, is your machine following the minimum bending radius? Are your hydraulic hoses clamped into place so to prevent the rubbing that occurs when under pressure? When you are routing hydraulic hoses through a structure that pivots can you prevent these hoses from undergoing strain? Will your hoses clear obstructions, other pinch points, and will not be subject to unnecessary rubbing? Have you made your hose as short as possible to reduce wear? Can you change a crimp hydraulic hose end to provide better routing? Have you eliminated as many twists as possible? It is necessary to pay close attention to these questions when you are designing your hydraulic hose system.

 

 

August 8, 2011

Hydraulic Fitting Tips and Techniques

 

Flat face hydraulic fittings and hydraulic hose are the best due to the excellent sealing arrangement and also the torque set up on the hose crimp end. The benefit of JIC tapered ends is that they do not ever fully bottom out so it can be very easy to over-tighten a JIC hydraulic hose fitting. Flat face fittings are sometimes preferred because you have to make contact with a flat surface before you torque to spec. It is quite fail proof. Yet on JIC fitting hose ends a major benefit is that even hand tightened JIC hose will hold until they vibrate off.

Always use the proper tools for applying torque onto hydraulic hose fittings. Most of the larger manufacturing hose fitting companies have their own torque wrenches for specific sizes and types of hose. Although this isn't completely necessary, it should be considered for highly sensitive installations. All that matters is to reach 75% of the proof load on a bolt so there is a considerable amount of range.

Engine hoses fittings require tighter tolerances because of the high temperatures and vibration loads. Also, if a hydraulic hose line blow off inside an engine housing and sprays oil onto a red hot components, the fire that could result will probably cause significant damage to your machine. Many off-road equipment have small gear pumps that are mounted on the front of engines with poor hydraulic hose routings. Special attention has to be paid to the fittings in these cases so they remain on and provide years of worry free function.

 

 

July 7, 2011

Testing Hydraulic Hose

 

Hydraulic hoses transport hydraulic fluid to other components in hydraulic systems such as valves, actuators, and work tools. Hydraulic hose as multiple layers to reinforce the assembly as often very high pressures can exist in the circuit. Proper testing is necessary before fitting a hose to a machine to determine the correct pressures required in operation. There are multiple ways to test hydraulic hose including the following:

Burst Pressure: This test takes the hose to the maximum pressure needed to tear through the skin of the hose. Once the hose is destroyed, the pressure recorded is then known as the burst pressure. The hose pieces used for this test are relatively short and are not usable after the test.

Proof Pressure: This test is to determine how much a hydraulic hose deforms over time when subjected to a high pressure (normally 50% of the burst pressure). Elongation, contraction, tearing, and changes in the circumference of the hose are watched for. Over time, if a hose cannot stand up to the proof pressure, it will fatigue and deform.

Hold Test: This test holds the maximum pressure a hose may see in a hydraulic system for the length of time that may be experienced while in that system. Again, as in the proof pressure test, elongation and contraction are observed and recorded.