Category Archives: Hose Master

Properly Measure Metal Hose Length: An Important Factor

There are several important factors to note when designing a metal hose assembly: alloy, fittings, media, pressure, and so on. One of the most crucial factors that is often taken for granted in industrial applications is hose length.  Utilizing the incorrect length in an assembly can be detrimental to its cycle life and potentially result in failure in an assembly.  If an assembly is too short, there is potential for the corrugation geometry to be deformed as the assembly is stretched between the connecting points.  Conversely, if an assembly is too long, it risks being over-bent as the hose tries to move out of its own way. To avoid these unnecessary failures, let’s review the steps to properly measure metal hose assemblies.

How to Measure Metal Hose Assemblies

picture of OAL and live lengthTo calculate the proper length of an assembly, it is first necessary to verify that the existing installation was properly designed.  Indication of improper design are factors such as torsion, over-bending, or compression of the assembly, which can lead to premature failure.

Next, you will need to measure the overall length of the assembly. The overall length is the total length of the assembly from end-to-end. When measuring for overall length, it is important to be aware that the points from which measurement should be taken vary between fitting types.  Measuring for overall length from an incorrect point on a fitting would result in an inaccurate measurement. How to measure various fitting types are as follows:

  • picture of measurements with various fittingsJIC/SAE Fittings: Measure from the seat of the fitting
  • Elbows: Measure to the center line of the fitting
  • Fixed Flanges: Measure to the face of the flange
  • Floating Flanges: Measure to the face of the stub end
  • Threaded Fittings: Measure to the end of the fitting

Finally, make sure that there is enough live length in the assembly to accommodate the required movements during service.  The live length is the portion of the assembly that is “active,” or has the ability to flex while in service. There are various formulas available to help calculate these length requirements. If it is determined that the existing live length is insufficient to accommodate the required movements, then Gallagher’s engineering team can provide expertise in appropriately adjusting the overall length of the design.

Utilizing these guidelines when measuring metal hose assemblies will help to ensure that an assembly is designed to sufficiently support the intended application.

Meeting the Tightest Tolerances

After proper measurement and design, it is important for a metal hose assembly to meet certain tolerance requirements as well. NAHAD sets guidelines for metal hose manufacturers in regards to the length tolerances to which a finished hose assembly must conform. Hose Master’s metal hoses are able to hold to those tolerances, as well as tighter specifications when the application requires. Adhering to strict tolerances in a completed assembly not only allows for solutions to the most stringent of applications, but also aids in providing maximum reliability, longevity, and safety.

For More Difficult Measurements

Taking measurements in the field can be difficult, especially if the installed assembly contains bends. For more difficult measurements, Gallagher can help.


The original article was written by Abby Svitana, Market Analyst at Hose Master.

For more information about measuring metal hose or for general inquiries about metal hose products, contact Gallagher Fluid Seals today.

Low-Temperature Applications: Can I Use a Metal Hose?

Use Metal HoseIt comes as no surprise that metal hose is the preferred choice for high-temperature applications. But what about low-temperature applications? This is a question frequently seen from customers. The simple answer is yes- metal hose is a great option for low-temperature applications. However, there are important factors that should be considered before making a recommendation.

Service Conditions

Before recommending a particular metal hose for a low-temperature application, the conditions that the hose will experience while in service should be identified. For example, what are the minimum and maximum temperatures of the application? If the assembly is going to be exposed to wide temperature variances, it is important to determine how frequently and rapidly the temperature will change. Metals expand and contract as they heat and cool, and they do so at different rates depending on the alloy.

Severe fluctuations in operating temperature can apply stress on welded joints as the base materials expand and contract, which may cause cracks to form.

One way to verify that an assembly will be able to accommodate these stresses safely is by conducting a “cold shock” test. Cold shock (aka “thermal shock”) testing is performed by plunging an assembly into a cryogenic bath, then allowing it to return to room temperature (or to the highest temperature to which it will be exposed), followed by various testing and inspection. This ensures that the welds will not crack when exposed to similar temperature extremes while in service.

Another service condition to identify is whether the temperature extremes will be present inside the metal hose (the media temperature) or outside the hose (the external environment). Will the hose be buried in ice? Will it have cryogenic liquids flowing through it? Is there a chance the media could freeze and change into a solid? Is it possible for frost to build-up on the hose exterior? These are all potentially damaging conditions that can be mitigated by selecting the correct assembly for the job.

picture of trace assembly
A traced assembly can be used to regulate media temperature.

For example, an application in which the metal hose may surrounded by a cold exterior environment may be best served by utilizing a traced assembly. It’s often recommended to use the STAMPED acronym to assist in identifying the service conditions for any hose application.

Standards and Certifications

Along with service conditions, it is important to also identify any standards that must be met in an application. This can be a challenge because there are different standards that may apply depending on the alloy, the forming process (cast, forged, drawn, etc.) and the finished product (hose, pipe, flanges, etc.).

Hose Master uses the low temperature ratings in the ASME Process Piping Code B31.3, as well as other internationally recognized standards. Identifying the applicable standard is important because different standards may have different low temperature ratings for the same alloy.

When identifying standards, it is also important to note that a particular alloy may have multiple certifications, meaning it complies with two (or more) standards, each of which may offer different ratings for a given alloy. For example, many of our alloys comply with both ASTM and EN (European) specifications. In these instances, the standard specified by the customer dictates the minimum allowable temperature rating.

Finally, the method of fabrication may affect the allowable low temperature limits. Many standards include or make reference to various welding requirements, many of which require the welders to achieve and maintain compliance to those standards through thorough education, testing, and audits. These standards may dictate the allowable low-temperature limits for a welder’s certification, superseding the low-temperature limits of the materials being joined.

Selecting a Metal Hose for a Low-Temperature Application

In summary, there is no one answer to “how low you can go” in regards to operating temperatures for metal hose. Finding out as much as possible about the intended application, including any applicable standards, ensures not only that the materials of the assembly will be able to handle the application, but also that the assembly will conform to any required specifications.


The original article was written by Abby Svitana, Market Analyst at Hose Master.

Gallagher Fluid Seals is an authorized distributor of Hose Master. For more information about Hose Master products or if you have a custom engineering need, please contact Gallagher Fluid Seals.

Interlocked Hose: Combating Common Failures

picture of metal hoseAs Albert Einstein once said, “The only source of knowledge is experience.” When it comes to interlocked hose, Hose Master has had a fair share of experience.  While other product lines have been added and developed over the years, Hose Master has been manufacturing and continuously refining interlocked hose since the company opened its doors in 1982.  During that time, they’ve seen hoses both excel in the field, as well as fail from a variety of factors. However, in their decades of experience, the majority of interlocked hose failures can be attributed to one of three failure modes: torque, abrasion, and over-bending.

Torque Failures

If an interlocked hose is torqued, it can cause the profile to come unlocked from itself.

Torque is arguably the greatest enemy of interlocked hoses. In any piping installation, torque can wreak havoc on the components in the system, but this is especially true for interlocked hose given its construction. Interlocked hose is made using a single strip of stainless steel. The shaping process performed on this strip makes it able to interlock onto itself and is what gives an interlocked hose its ability to flex. When an interlocked hose is torqued it begins to ‘unwind,’ which loosens the interlocked profile, increases leakage and creates a possible unraveling of the hose. Torquing the hose is a common problem because it is often a direct result of mishandling the hose in its application, but can be prevented with proper handling. However, if a hose has been known to fail from torque consistently or will see excessive handling, manufacturers often offer varying options on interlocked hoses to help combat torque and make the hose more resilient.

Abrasion Failures

Abrasion is another common killer of interlocked metal hose. Interlocked hoses are often used in pneumatic transfer applications and the conveyed media is usually some sort of particulate. For example, powders, pellets, granules, and aggregate materials are all commonly transferred media in interlocked metal hoses. One issue with these media types is that they are known to be abrasive. While the degree of abrasiveness depends both on the media type and the speed at which the media is traveling through the hose, this abrasiveness can cause a problem. Metal hoses have a relatively smooth, hard interior which allows the material to move through it at a higher speed than other hose materials. In the case of finer media, this can result in a “sandblasting” effect, which can rapidly wear through the walls of the hose. The best way to avoid excessive abrasion is to make sure that there are no extreme bends in the hose and the hose construction is compatible with the media type. Adding a liner or using a heavier gauge of material are both good options for making the hose more robust.

Over-bending Failures

The interlocked guard on this assembly has been over-bent, causing it to pull away from the fitting.

Over-bending is the third most common failure mode seen with interlocked hoses. While interlocked hose can be quite rugged, once it becomes over bent it is much less forgiving than other hose types. Because the hose’s ability to flex comes from its interlocked profile, the flexing ability is mechanical (i.e. the metal strips sliding against each other) as opposed to the material stretching like with rubber or plastic hoses. If a hose is forced to bend beyond its capabilities, the metal profile becomes distorted and will not return to its original shape. This will negatively affect the hose’s ability to flex and transfer media, and can potentially lead to a loss of interlock. Luckily, because of the hose’s mechanical construction, you don’t have to guess where it’s bending limits are.  If the hose is being flexed to a point where it stops and the ridges are touching each other, do not continue to push as the hose has reached its bending limit.

Getting the Most from Interlocked Hose

Knowing these sources of interlocked hose failure can help prevent them in an application and, if identified early on, can be addressed in the hose’s construction before it ever sees service.


The original article was written by Abby Svitana, Market Analyst,  can be found on Hose Master’s website here.

For more information about metal hose applications, or how Gallagher Fluid Seals can help with your MRO and OEM applications, contact our engineering department.

Considerations for Using Metal Hose in Chemical Plants

Chemical plants are one of the biggest industrial users of corrugated metal hose assemblies. Processes performed in the plants involve some of the most demanding environments:

  • Temperatures ranging from extreme heat to cryogenics
  • Mixing and transfer of hazardous compounds
  • Equipment configurations that result in less-than-ideal piping situations

Metal hose can handle all of these factors and has some other inherent benefits over other hose types when it comes to the kind of applications seen in chemical plants. Let’s dig into some of the main areas of consideration and concern when dealing with chemical hoses.

Metal Hose Handling Considerations

Mishandling of hoses is one of the main contributors to premature failure. Because chemical plants have so many different inputs and outputs, hoses are often used to facilitate the transfer of chemicals from trucks, trains, or barges to the plant and even within the plant from one unit to another. Chemical blending manifolds are a great example of this, where a single hose assembly may be used for various connections at different times depending on what operations the plant is performing.

Cam Coupling PictureThe need to easily connect and disconnect these hoses quickly and often makes cam and groove couplings a popular choice for chemical plants. When moving hoses from one outlet to another, it’s tempting for users to abuse the “arms” on the fitting and over-bend the hose or torque it into position. Always try and keep the hose as straight as possible, and avoid twisting it. Additionally, hoses are made to flex, but extremely tight bends (especially near the end fitting) can damage the hose and cause it to fail prematurely. Operators should keep this in mind to prevent deformation of the hose when making connections.

Metal Hose Attributes

There are several intrinsic features of metal hose assemblies that make them well-suited for chemical plant service. Chiefly among them is that they are not susceptible to permeation. This is a huge benefit for both operator safety, and plant safety. The metal core is puncture-resistant, and in the event of a leak, the hose will typically develop a small crack or pin-hole and does not burst apart.

Metal hoses also have a more compact end fitting configuration. Because end fittings are welded onto the end of the hose instead of a barbed or crimped mechanical attachment, they don’t take up as much of the hose’s flexible length. This results in more working live length compared to non-metallic assemblies, which further facilitates handling and easier installation by the operators. It also means that metal hose is easily customized without the need for adapters. Stainless steel fabrication techniques provide the ability to use a wide array of fitting configurations, and can be tailored to prevent media entrapment, resist end-pull, or to accommodate high system pressures.

Finally, one of the handling benefits of metal hose is its light weight. Calling metal hose lightweight might sound contradictory, but pound for pound, metal hoses generally offer higher working pressures than rubber or composite chemical transfer hoses. This gives metal hose a wide range of potential applications, and also translates into easier handling and installation by operators. Continue reading Considerations for Using Metal Hose in Chemical Plants

Maximizing Service Life: Recommendations for Storing Metal Hoses

When it comes to industrial products and applications, much of the discussion is focused on how to pair the right product and the right application. There are many different manufacturers of components that offer different features and benefits to suit the huge variety of factors that can affect plant components regardless of the industry. Vibration, corrosion, media consideration, service life, flow velocities, fluid dynamics…there are too many to list here! But what often gets ignored is how to handle and store those products before they ever get put into service.

picture of industryAfter personnel safety, avoiding unplanned downtime is the main priority for all industrial operations. Plants typically keep an inventory of maintenance items like hoses on hand to swap out as needed to minimize lost production time. Unfortunately, this inventory is not always stored or cared for properly. Some power plants keep replacement hoses, pumps, gaskets, and flanges on the ground outside. The end result of this kind of storage often defeats the purpose of having inventory parts because they can fail or lose significant service life before they’re ever even used. While these storage concepts apply to all maintenance components, let’s discuss metal hoses specifically.

External Considerations

The storing of hoses outside may come as a bit of a surprise (or may not) but it’s actually relatively common. Rain or dust seem like insignificant elements to stainless steel but they can actually facilitate a great deal of damage, especially over time. With rain, the phrase “evaporation equals concentration” helps to illustrate this point. Everything that is picked up by the rainwater on its way down (including nearby plant gasses) is delivered in a diluted state, but as the water slowly dries up, it leaves behind a concentrated residue that can cause corrosion (especially if the hose is in a position to collect water that can then pool on the interior).

Dust and particulate matter can do this too, especially inside the plant. Maintenance storage cribs and spare parts inventories can often be found near the equipment they’re meant to service. Heavy dust and particulate matter from process equipment can pick up other chemicals and off gases that are present in the plant, and carry them down onto the outside of uncovered hoses. This new mixture can cause unintentional chemical reactions that can corrode the exterior of the hose. Here is a specific example: In a coal-fired power plant – a baghouse collecting ash was improperly releasing a large amount of particulate…which then combined with lime dust and landed on nearby hose assemblies causing the exterior to become embrittled and fail. Even in cases where corrosion isn’t an issue, these fines can buildup on the outside of the hose in-between the corrugations and underneath the braid. This can be difficult or impossible to clean out, and can affect the hose corrugation’s ability to flex, or can become entrapped in the braid causing increased wear.

Hose Options for Storage

Fortunately, there are simple remedies for most of these issues. It’s always up to the end-user how they want to properly address their plant processes: be it either with a modification of the hose itself, or by rearranging how they store the hoses in the plant. Let’s break down each one separately: Continue reading Maximizing Service Life: Recommendations for Storing Metal Hoses

How to Handle Corrosion in Your Mill

Avoiding as Much Unplanned Downtime as Possible

Steel mill operators don’t like to have downtime problems, in fact they can’t afford to.  They want to run as much as possible, and as efficiently as possible.  Production equals dollars.  As problems pop up that cause unplanned downtime or upset production (and subsequently get addressed) over the years, they’ve driven the industry to continue to change and evolve as a whole.  So the mills of today don’t have the same issues that mills did in the past.  You can’t as easily say “Hey, we saw this exact same problem up the street on their furnace!” the way you may have been able to 50 years ago.

That doesn’t mean that mills still don’t run into issues, they just tend to be a bit more personalized. And when you have a unique issue, you tend to get a unique solution.  A mill will do its best to solve its own problems, yet each mill has their own idiosyncrasies.  When these “little” problems pop up, the mill has to find a way to deal with it.  When it comes to problem-solving in mills, there are two main schools of thought: get to the real core of the problem and fix it as completely as possible for a lasting solution, or stabilize the issue and control it through regular coordinated maintenance.  Both strategies have the same end goal: avoid as much unplanned downtime as possible by solving the problem.  But which strategy is correct?

A Lasting Solution vs Regular Coordinated Maintenance

This is seen all the time with hoses and expansion joints.  To illustrate this issue, let’s use two real-life examples: Mill A and Mill B were both using Hose Master’s Annuflex hose assemblies to transfer cooling water on the caster and experiencing similar hose failures due to corrosion from an unknown source. Both Mills had seen unplanned downtime due to the failure of these hoses, but each had a different philosophy on how to solve to the problem.

picture of steel mill“Mill A” takes the long-term calculated approach.  They analyze it, looking at everything regarding the application to isolate the underlying issue.  Surrounding piping, surrounding equipment, the hose construction, the media inside the hose…and discover that the mold powder being used during the casting is mixing with cooling water spray, and floating down onto the outside of the hoses, causing them to corrode.  In the short term, they made piping adjustments and redesigned their Annuflex hose assemblies to be made out of ChemKing which uses a nobler alloy (Hastelloy C276) to resist the corrosion, and add an external guard to help prevent particulate from coming into contact with the hose in the first place.  They then plan to install a metal shield around the casting segment where the mold powder is originating to prevent it from escaping and damaging the surrounding equipment in the future.  This solution is more time consuming and more expensive, but the issue is solved for good and removes the need for regular maintenance!

“Mill B” sees the same problem for what it is at face value: just a hose failure.  Because the hoses have been allowed to stay in service for an extended period of time, they seek to remedy the maintenance issue of hoses failing unexpectedly. Because the mill has a planned maintenance outage every 6 months, scheduling the hoses to be replaced regularly at this time will remove the issue of unplanned failures.  In order to increase the service life and guarantee performance in-between the planned maintenance outages, they make the lateral switch from Annuflex to Masterflex.  The added flexibility ensures that all the assemblies they use on the caster will be flexible enough regardless of the slight differences in piping configuration,  and that the hoses will not fail due to fatigue. The standard alloy construction can withstand the corrosion long enough to survive between outages, so by replacing them all at once they now have taken control of the service life issue.  Because of the more economical construction, they can easily afford to replace the hoses at their planned intervals and avoid any further lost production!

So, Which Solution is Right?

Well – both are right. Each mill found a way to keep their production up-and-running that makes sense to them. The hose issue plays a very small part in the overall production flow of the mill, and how they strategize and organize their overall approach to maximizing production and uptime takes into account a huge number of variables.  When helping to solve these problems, manufacturers like Hose Master have to take these differences into account.  There’s more than one way to skin a cat; and what may work for one mill, may be an unacceptable solution in another.


The original article was written by Erik Kane and can be found on Hosemaster’s website.

Gallagher Fluid Seals is a preferred distributor of HoseMaster. To learn more about how we can help with your MRO solutions, contact Gallagher today.

Measuring Metal Hose Assembly Lengths

“Which way do I measure this metal hose?”

A common question among some customers who use metal hoses is: “Which way do I measure this metal hose?” Well, there’s a few different options.

  1. The first method is to measure the overall length of the assembly.
  2. Or, the live flexible length of the hose assembly can be measured.

Live Length vs Overall Length

Traditionally, the live length – or the amount picture showing live length versus overall lengthof flexible hose between the fitting – is used to determine whether there is sufficient hose length to accommodate a certain offset or movement, whereas the overall length of the assembly would be used to determine if the hose is going to fit in an application.

When measuring the overall length of the hose assembly, make sure to measure the overall length via end-of-fitting to end-of-fitting and if it has floating flanges on it, remember to measure to the face of the stub end on that floating flange.

JIC Swivel Fitting

If it’s a female JIC swivel fitting, however, it’s not necessary to measure the overall length to the end of the nut. Measure to the seat of the JIC inside the female swivel fitting. This is the standard for the metal hose industry.

Some customers may measure the overall diagram showing measurements with centerlinelength to the end of the JIC nut because some standards are measured differently by hydraulic manufacturers. If there are elbow fittings on the ends of the hose, metal hose industry standards dictate that measurements should be taken to the centerline of those elbow fittings rather than measuring the outside of the radius of the bend on those elbow fittings.

Laid flat with no kinks or bends

When measuring the length of a hose assembly, make sure it’s laid flat without any kinks or bends in the assembly. If it’s a strip wound hose assembly, ensure that strip wound hose is in its relaxed length, midway point between fully compressed and fully extended. Then, take the measurements on the length of that assembly.

For a great visual representation of measuring metal hose assembly lengths, watch this informative video below from Hose Master:


This video was produced by Hose Master and can be found on their Youtube channel or on their website.

For more information, contact Gallagher Fluid Seals or call 1-800-822-4063.

Metal Hose Application Do’s and Don’ts – Part 2

Metal hose applications can get tricky. Sometimes you can have problems or failures due to the surrounding piping system or because of the way the hose is installed.

Today we are going to discuss Part 2 of the do’s and don’ts when it comes to installing metal hose assemblies in a metal piping system.

Hoses can take a great deal of damage when they are torqued. Twisting it stretches the corrugations and the fitting wells and can cause it to fail. To prevent torque, don’t install the hose off-center.

When it tries to flex, the assembly will be torqued. Do install the hose in-line with itself; called in-plain. This prevents it from torquing when it flexes, and you should stick to one plain of movement. A quick test for in-plain could be done with either a sheet of paper or a flat surface like a table.

When handling long lengths or coils of hose, it’s important to make diagram of a hose wrapsure the hose doesn’t get twisted. Don’t grab one end of the coiled hose and walk away or pull on one end with the other end fixed. This will torque the hose. Do coil and uncoil it properly. Roll it like a tire or pretend like it would be on a reel and try not to twist it.

When installing a hose, significant physical damage can be done to the fitting, the welds, and the braid with the various tools that may be used to install it. Don’t use a wrench or other tools on the hose anywhere but on a hexpad. Gripping the hose by the braid, the braid collar, or the threads will damage the assembly. Do use a second wrench or a swivel-capable fitting when applicable to prevent twisting during the assembly installation.

Torquing the hose during installation is common and can be an issue. If the existing piping does not have any kind of swivel or rotation, don’t use an assembly with fixed-ends fittings at both ends. Otherwise, installation could torque the assembly and strain into service.

Do use a swivel, floating flange, or union, or other fitting that allows the hose assembly to twist during installation.

Follow these tips can help maximize your hose safety and the safety of your plant personnel. If you missed it, make sure to check out Part 1 of the video series.


This video was produced by Hose Master and can be found on their Youtube channel or on their website.

PTFE Liner for Corrugated Metal Hose

Gallagher Fluid Seals is a distributor of Hose Master corrugated metal hose and expansion joints.  With the largest in-house fabrication footprint in the U.S. of any metal hose manufacturer (350,000 square feet of manufacturing space) and 80+ ASME IX Certified welders on staff,  Hose Master delivers the highest quality products for the most demanding applications.

The following article can be found on Hose Master’s Insights Blog.


Should I Install a PTFE Liner Inside a Corrugated Metal Hose?

by Frank Caprio, Dean of Hose Master University
Corrugated Metal Hose
See the hose peeking out between the collars? Me neither.

We get various requests from our customers for non-traditional hose assembly constructions that they believe will help them solve tough application problems. Over the years, we’ve seen a lot of these, and some are pretty inventive, even if they’re not the best solution. Some other proposed solutions…not so good!

One especially challenging application that can drive people to consider specialized solutions is when the hose is exposed to corrosive media or environments. Typically, corrosion can be avoided simply by selecting an alloy that is resistant to chemical attack. However, certain refinery applications (such as those found in Cokers or FCCUs) entail operating conditions where some manufacturers recommend a special corrugated metal hose assembly which has been fitted with a liner made from smooth PTFE tubing. While this special construction sounds good in theory, it can create more problems than it solves. Let’s take a closer look at PTFE-lined corrugated hoses.

Continue reading PTFE Liner for Corrugated Metal Hose