Calipers, Combs, And Guides Help Make Sense of Threads

Posted by Alecia Robinson on Thu, Nov 09, 2017 @ 12:11 PM

Scratching your head about threads? We have three tools that solve the mystery

  The Pipe and Tube Sizes board (pictured above) is at our back counter. Bring in your fittings and we can help determine the sizing.
  The thread pitch gauge is another tool we use to help with thread size - it's even available for purchase! To get more info on sizing, download the Thread and End Connection ID Guide PDF.

Can you tell the thread size and thread pitch on a component just by looking at it? Neither can we. That's why we have tools that eliminate the guesswork.

When you look at a thread, you'll see peaks (called crests) and valleys (called roots). The part in between the crest and the root is called the flank. The first thing you want to find out is whether the crests are all the same diameter. That would mean you have straight threads. So we get out our calipers and measure the first, fourth and last crests. If the measurements are the same, you have straight threads. If you get three different measurements, you have tapered threads.

There's another way to tell, provided that you are working with Swagelok parts. Other than standard NPT, Swagelok fittings are uniquely marked to indicate ISO tapered or ISO parallel threads.

Some people are surprised to learn that straight threads are not designed to seal on their own. They require a gasket, O-ring or some kind of metal-to-metal contact to finish the job.

Tapered threads are designed to seal as the mating threads are drawn together. In addition, some kind of sealant is necessary to prevent leaks. That's usually PTFE tape or a product such as SWAK.

Here comes the "pitch"

Next you need to know how close together the crests are. That's the pitch, usually expressed as the number of threads per inch.

Straight threads come in three standard kinds of measurements. The most common are SAE (Society of Automotive Engineers), ISO 228/1 (also known as British Standard Pipe Parallel), and metric. Tapered threads also have several standard forms of measurement: NPT (National Pipe Thread), ISO 7/1 (also known as British Standard Pipe), and metric.

The flanks can come in different angles, known as Whitworth, unified, or metric.

To discover the pitch, we use a thread comb, also known as a pitch gauge. It looks a bit like a pocketknife, but the blades have saw-tooth edges that fit into the thread roots. We simply try different blades until we find an exact match. Some fractional and metric thread forms are very similar, so we take the time to make sure it's a true fit.

You also can turn to the Swagelok Thread and End Connection Identification Guide, which you can download for free. It has all the terminology, thread ID reference tables, and step-by-step instructions for identifying threads.

Lastly, Edmonton Valve & Fitting has a board with various sizes of threads. If you come in with a part, we can see which sample it fits.

Obviously, the threads on two parts have to have the same size and type of threads if you want to connect them. But you don't have to guess. Check in with Edmonton Valve & Fitting and we'll work with you to get the right answer. Give us a call at 780.437.0640 or get in touch below.



Topics: Valves, Fittings, Measurement Devices

Small Hole Creates A Big Advantage For Flush Systems

Posted by Alecia Robinson on Thu, Nov 02, 2017 @ 13:11 PM

Special Swagelok flange adapter with pre-drilled orifice simplifies design


Threaded connections can be problematic when dealing with rotating equipment. Swagelok offers orifice flanges to reduce the number of threaded connections within your flush systems. Get in touch with us today to learn more.


Sometimes a small modification can make a big difference in a fluid system component. Take, for instance, Swagelok's flange adapters. We've written about them before, explaining how they provide a threadless, weldless transition from flanged pipe to tubing.

We have a special flange adapter made with flush systems in mind. For our customers with rotating equipment, we offer the Swagelok orifice union and orifice flange adapters. Because the orifice is pre-drilled into the flange, between the tube fitting and the flange itself, you get a unique solution that helps reduce the number of threaded connections in your flush systems. You no longer need to worry about threaded adapters leaking due to vibration or freeze-thaw cycles. You'll also save money by not having to weld the flange.

As with all our flange adapters, they reduce both the number of connections and the overall weight.

Typically the orifice is drilled out to 1/8 inch, but we can supply custom sizes too.

If you are already using flanges to simplify your system design, reduce weight and end up with fewer leak points, you already understand the value of these flange adapters for flush systems in rotary equipment. If you haven't yet made the switch to flange adapters, we can help you get started. All it takes is a call to 780-437-0640, or you can contact us through our website.

Additional resources


Topics: Tubing, Fittings

What Are Swagelok's PFA Fittings All About?

Posted by Adam Telenko on Wed, Oct 25, 2017 @ 09:10 AM

PFA 1.jpgpfa 2.jpg

We have a full line of PFA fittings, valves, and tubing, to get your copy of these catalogues download them below.

PFA Catalogues

Swagelok carries a variety of materials for our fittings and tubing so selecting the correct one for the job can be daunting. We discussed some of the options in our blog on special alloys earlier this year but today we will further explore our PFA line of tubing and fittings.

PFA, or Perfluoroalkoxy, is a type of fluoropolymer. It has very similar properties as the more common polytetrafluoroethylene (PTFE) – also called Teflon.

PFA is generally used for plastic lab equipment because of its optical transparency, overall flexibility, and extreme resistance to chemical attack. PFA is also often used as tubing for handling critical or highly corrosive processes.

What to consider

You can use Teflon or metal fittings with Swagelok PFA tubing. Just remember using PFA fittings with PFA tubing you need to use a Swagelok groove cutting tool to 'groove' the tubing and achieve higher working pressures.

Some other important things to consider when selecting PFA tubing and fittings are the following:
  • An audible ‘click’ sound ensures tubing is properly inserted
  • 316 SS fittings can be used with PFA tubing
  • PFA Plug and Needle valves are available 

How to order

PFA part numbers are slightly different than Swagelok’s common tube fittings, for example:

  • PFA-420-1-4 for a 1/4" male connector
  • PFA-820-6 for a 1/2” tube union

But don't worry about memorizing part numbers, give your local Swagelok experts a call and we will be glad to help out.

Additional resources

In a hurry or have a question? Please click here to get in touch - we respond fast! Or call 780.437.0640.


Topics: Tubing, Valves, Hoses, Fittings

Strength and Simplicity: Medium Pressure Fittings

Posted by Alecia Robinson on Tue, Aug 15, 2017 @ 14:08 PM

They handle extra pressure without requiring any extra tools or extra effort

Medium pressure fittings.jpg

When you need a robust fitting that can handle up to 20 000 psig with an easy installation, Swagelok medium pressure fittings are a great solution. Download the Medium- and High- Pressure Fittings Catalogue to find out more.

Earlier this year we wrote about Swagelok's IPT fittings for high-pressure applications. But maybe you are looking or something that takes less time to install and can be verified for proper installation. For pressures that don't go beyond 20,000 psig (1378 bar), consider Swagelok's line of medium-pressure fittings.

With our medium-pressure fittings, you don't need any special tools or special skills. You don't have to cut threads or cone the ends of the tubing, as you would for the high-pressure fittings.

The simple two-piece design of Swagelok's medium-pressure tube fittings and adapters consists of a female fitting body and preassembled cartridge containing the male nut and color-coded front and back ferrules on a disposable plastic arbor. The preassembled cartridge ensures that installers will have the correct ferrule orientation, plus visual confirmation when the ferrule is present and properly installed in the female body.

The components are released only after the nut is threaded finger-tight on the fitting body.

Key differences

While Swagelok's medium-pressure fittings don't require special tools or skills, their installation differs from standard Swagelok fittings in a few key areas. 

First, it takes only one full turn to pull up the fitting, not the turn-and-a-quarter of our standard fitting. Second, proper tightening can be measured by torque as well as with our gap-measuring gauge. That means this is one of the very few components in the Swagelok catalog that can be mixed into your fluid system without having to upgrade all the fittings at once.

In our medium-pressure line we have straight fittings, 90-degree elbows, tees and union crosses, plus caps and plugs.

The strain-hardened stainless steel bodies offer lightweight space-saving designs. You'll also get Swagelok's patented low-temperature case hardening processing of the ferrules and nut.

Your fluid system needs to run on the right pressure for the job, and you need the right fittings for the pressure. Edmonton Valve & Fitting can make sure you get the right match. Call us at 780-437-0640 or contact us through our website.

Additional resources


Topics: Catalogues, Fittings

The Advantages of Swagelok VCR and VCO Fittings

Posted by Alecia Robinson on Thu, Aug 03, 2017 @ 16:08 PM

Most people know Swagelok for our two-ferrule Tube Fitting. However, we also carry two valuable lines of face seal fittings.


VCR and VCO zero clearance allows for inline service. Download the VCR & VCO catalogue today for more information.

The VCR and VCO product lines are two more items that could save you a lot of time and money down the road. The primary distinguishing feature of the VCR and VCO fittings is that they have a zero clearance capability. This means that unlike pipe, tube, and weld end connections, the VCR and VCO fittings can be disassembled in line – with no clearance requirements. VCRs and VCOs serve as a make and break point – a spot to access the system for repair and upgrades without having to remove multiple parts.

They also feature silver plating on all female threads, which prevents galling and eliminates the need for thread tape, which improves ease of installation. There are also leak test ports on the side of each nut, where the metal faces come into contact and the seal takes place. Lastly, there is a split-nut available, which further increases the ease of assembly and reassembly.

Easy access

Thanks to the flat face seal of both the VCOs and VCRs, you have unlimited make and remake capabilities. All you have to do is replace the gasket on the VCR  each time you remake the connection. The gasket is the least expensive piece of the assembly, so replacing this is much more cost effective than replacing the whole assembly. When installing the VCRs and VCOs, tighten the nut finger tight and then use a wrench to turn the nut 1/8 of a turn.

There are certain capabilities that differ between the two products. For example, in high temperature applications, the VCR  is a better option because the metal gaskets allow for a much higher temperature capability; as high as 1000 F for a stainless steel gasket.

Assembly options

VCO Assemblies:

Gland + Body + Nut


VCR Assemblies:

Female Nut + 2 Glands + Gasket + Body (Male Nut)


Female Nut + Gland + Gasket + Body



Multiple applications

VCRs and VCOs are popular in hydraulic systems as well as welded and threaded systems. They also provide a great transition from such systems to a tubing system, by using a tube adapter end connection. Thanks to the variety in end connections that are available in VCRs and VCOs from Swagelok, there are endless combinations available to our customers. For more information on how VCR and VCO fittings could work for you, download the catalogues, or ask us.


Topics: Fittings

Dielectric Fittings Prevent Shocking Results

Posted by Alecia Robinson on Thu, May 18, 2017 @ 12:05 PM

A buildup of static electricity can make a mess of analytical equipment

dielectric fitting.png

Swagelok's dielectric fittings and adapters isolate monitoring instruments from the effects of electrical current; to find out more about dielectric fittings download the catalogue today.

As analytical instrumentation becomes more sophisticated and sensitive, it's more important than ever to protect the equipment by using dielectric fittings and adapters. They isolate the instruments from the effects of electrical currents and maintaining full fluid flow.

Running fluid through a line can cause a natural buildup of static electricity. If that ever reaches the metering device, it could make all your readings unreliable, or knock them out entirely. In a system running volatile fluids, a static discharge could cause an explosion.

The dielectric fitting itself is simple. It starts with the classic Swagelok design, then adds a thermoplastic insulator to prevent electricity conduction from a main area to a metering device. The design is unique in the way it separates the two primary functions of electrical insulation and fluid containment. Since the insulators are not primary seals, the material and design provide high dielectric strength over a wide range of operating and climactic conditions.

A Viton O-ring and TFE backup ring serve as the primary fluid seal. The seal is completely self-contained and requires no maintenance.

Too relaxed

No one sets out to create a problem in their fluid system design. What often happens is that people get used to a certain approach, and don't always take into account the changing technology. Some older analytical equipment was built in a way that required a large sample of chemical or mixture to meet the requirements for a good reading. Today's more sensitive equipment can get the job done with smaller samples, but also are more susceptible to an unwanted electrical change.

Someone who habitually falls back on "the way we have always done it" may even think they're saving a few dollars by using standard fittings. But it's foolish to cut corners by installing regular fittings. Dielectric fittings should be standard practice, especially in any areas that have been deemed intrinsically safe.

Take a look at the dielectric fittings in our catalogue, then call us at 780-437-0640 or contact us through our website to talk about integrating dielectric fittings into your system.

Additional resources


Topics: Fittings, Measurement Devices

Sometimes Stainless Isn't Enough

Posted by Tristian McCallion on Wed, Mar 15, 2017 @ 10:03 AM

Special Alloys are used in unique applications where stainless steel cannot hold up to the corrosive material.

Special Alloys.png

Swagelok carries an array of special alloys to meet our customers requirements, to find out more about special alloy uses download our Special Alloy catalogue.

How many materials can you get Swagelok tube fittings in? Two? Five?  Would you believe that our standard material list includes 16 different materials from nylon to titanium?

316 stainless is our most common material and is good for 95% of applications in northern Alberta but there are some limitations.

Special alloys

In the SAGD world on the water treatment side, there is often an elevated chlorine level in the boiler water.  Chlorine and stainless steels don’t mix well and it is common to find stress corrosion cracking in applications that have high chloride levels and stainless steel fittings and tubing.  There are a number of other materials that we offer that can provide the necessary corrosion resistance in this type of application, like Monel, or our high temperature carbon steel.

This is just one application where we are able to help out with special alloys.  Some of the other materials that we can provide include:

Teflon and PFA:  PFA is the injection moldable version of Teflon.  These materials provide for excellent chemical resistance to a wide range of different fluids.  Water treatment facilities are large users of PFA and Teflon fittings.

Alloy 400, or Monel:  This is a high nickel alloy that has excellent resistance to corrosion in reducing environments with fluids like hydrochloric, sulfuric and hydrofluoric acids.  It is also a commonly referenced material when looking at NACE specs.

Inconel 625: A very corrosion resistant in oxidizing and reducing media.  It offers high strength and good ductility.  It also has very good performance in sour gas (NACE MR0175)

Hastelloys:  C-276, C-22, B-2 are some of the grades that you can find, with C-276 being one of the more common alloys we deal with locally in this range.  It offers excellent resistance to pitting and crevice corrosion and immunity to stress corrosion cracking.

Duplex stainless steels:  A number of different materials are available here: 2205, 2507 super duplex and even the excitingly named 2707 hyper duplex stainless.  Often seen in offshore applications these materials have higher strength than 316 stainless and may have better resistance to pitting, crevice and general corrosion.

Swagelok makes fittings, valves and other components out of a wide range of different materials and would be happy to work on your applications with you.

Our Special Alloy catalogue provides additional information on some of the special alloys offered by Swagelok.

Additional resources

In a hurry or have a question? Please click here to get in touch - we respond fast! Or call 780.437.0640


Topics: local expert, Valves, Fittings

Grace Under Pressure: Swagelok's IPT Fittings

Posted by Alecia Robinson on Tue, Jan 10, 2017 @ 09:01 AM

Cone-and-thread fittings make a tight, reliable seal

 IPT Fitting Diagram.png

 The image above highlights the key components of the IPT fitting.The cone and thread fittings are desgined to withstand medium and high pressure environments.

IPT Download

When you have a fluid system running at above-normal pressures, you need something sturdier than the standard Swagelok tube fitting. For great performance under pressure, we have the IPT series. We offer two types of IPT fittings: The medium pressure fittings are designed for up to 20,000 psig or 1378 bar and the high-pressure fittings for up to 60,000 psig or 4134 bar.

These cone-and-thread fittings are designed specifically for the oil and gas, chemical, petrochemical, water jet cutting and blasting, and aerospace industries.

A good angle

The threaded tubing ends with a cone at a 59-degree angle. It fits into the primary seal surface, which has a 60-degree angle. All manufacturers use the same interference angle between the male cone and female body, which allows for interchangeability. This is one of the rare times Swagelok gives a green light to mixing its components with those from other manufacturers.

A collar surrounds this area. A threaded part, called a gland, creates a load on the collar to ensure a seal on the tubing. This is another area where standard procedure departs from the standard Swagelok tube fitting. Instead of prescribing a fixed number of turns for proper tightening, IPT fittings require a specific amount of torque.

Another key element in IPT fittings is a weep hole at the collar. It's a quick way to detect leaks and verify proper installation. Even steam leaks are easy to spot by applying a bit of Snoop leak detector at the weep hole. When removing the collar and gland for maintenance, the weep hole also releases trapped pressure to avoid a "live loaded" thread. But never use the weep hole to bleed the system or vent system pressure. This could cause a pressure-injection injury to your employees.

The medium-pressure and high-pressure components have the same basic design, but the parts are not interchangeable. The high-pressure version has a larger collar and gland, and the collar sits inside the gland when assembled. The high-pressure design also uses thicker wall tubing to compensate for threads.

Both the medium-pressure and high-pressure versions have anti-vibration assemblies available. That's useful when the fittings are placed near a compressor, for example. Again, the assemblies are not interchangeable. An easy way to spot the high-pressure version is its additional slotted collet, which must be pointed in the right direction for assembly. (The medium-pressure slotted collet can be oriented in either direction.)

Tough tubing

The special cold-drawn tubing used with IPT fittings is also different from the standard used in other applications. It's harder and has thicker walls in order to allow cutting away material for threads with a tap-and-die set. In a sense it's really a very small pipe. We'll gladly rent you the tools to do the coning and threading, or we can do it for you if you tell us the dimensions you need.

Another difference from ordinary tubing is the outer diameter, which is slightly smaller than the nominal tube OD.

The harder steel and thicker walls also come into play when bending the tubing. The bend radius must be larger, at least 1.25 inches for quarter-inch tubing. (Keep that in mind when planning out your installation, as you'll need some extra space.) Don't try using a hand tube bender; use the bench-top version as you will also experience greater spring back.

Even extra-tough tubing is softened by heat. That means high temperatures (greater than 93.33º C) will have an impact on the pressure rating of the connection. At 204º C, the pressure rating drops to 93 percent of normal for strain-hardened 316 stainless. At 537º C it drops to 84 percent of normal.

Multiple assemblies

If you've properly installed your IPT fittings, you can take them apart and reassemble them up to five times. But it's important to make sure the cone stays perfectly smooth. If the cone doesn't fit tight against the body, you won't get a proper seal. Tubing can be re-coned if you aren't sure, though be aware that doing so can shorten the length of the tubing.

So don't let the pressure get to you the IPT download has even more information on all the types of IPT fittings and ordering information.

IPT Download


Additional resources

In a hurry or have a question? Please click here to get in touch - we respond fast! 
Or call 780-437-0640

Topics: Tubing, Fittings

Specifically Made for Alberta's Needs: The ZSML Fitting

Posted by Katie Reid on Tue, Dec 13, 2016 @ 14:12 PM

Swagelok 1035 Grade Carbon Steel, MoS2 coating helps the tube fittings withstand the heat of steam-assisted gravity drainage

ZSML fittings.png

Swagelok's ZSML fitting, as pictured above, is specially coated with a 1035 Grade Carbon Steel, MoS2 covering that was developed for the SAGD industry in Northern Alberta. If you would like more information on this product line, get in touch with us today.


Eighty percent of Alberta's oil sands are too far below the surface for open pit mining. To get the oil out, companies have to use methods such as steam-assisted gravity drainage. And for SAGD to work properly, it needs parts such as Swagelok's ZSML fitting. To understand why ZSML fittings are so important, take a quick look at how SAGD works.

Get moving

SAGD uses a pair of horizontal wells, one about 4 to 6 metres above the other. Steam is injected into the upper well, heating up the surrounding oil. That makes the oil less viscous. Gravity then draws the oil down to the second well, where it can be extracted.

The fittings on the steam generators must withstand high temperatures, and even Swagelok's ordinary carbon steel fitting won't do. That's why Swagelok came up with the ZSML fitting. This unique coating (1035 Grade Carbon Steel, MoS2) allows the fitting to withstand temperatures of up to 427 degrees C! But you won't find it in any Swagelok catalogue as it was designed specifically for Alberta and our extreme conditions. Swagelok even sent its engineers to SAGD sites to see the field conditions before creating the ZSML fitting. 

Inside knowledge

You might wonder how our customers know how to order the ZSML fittings if they aren't in the catalogue. Most of those who are involved in setting up SAGD systems are already familiar with this special fitting. We also can provide a value added service of going into the field to teach maintenance and repair crews about this specific part if needed.

Maybe you have a special need and can't find the kinds of parts you are looking for. Don't assume that the catalogue tells you everything you'd want to know. Give Edmonton Valve & Fitting a call. We might know of a component that will do the job for you. And it's even possible that Swagelok would be willing to design something if it doesn't already exist.  Ask us about the ZSML fitting here.



Additional resources

In a hurry or have a question? Please click here to get in touch - we respond fast! Or call 780.437.0640


Topics: Value Added Services, Steam, Fittings

Your Checklist for Tubing Quality

Posted by Tristian McCallion on Fri, Dec 09, 2016 @ 11:12 AM

Quality is one of Swagelok's six core values; here we offer up a checklist to make sure you get the best quality out of your tubing and what to look for

Tubing EVF.png

It's important to know what to look for in tubing quality and we have you covered with our checklist below. Still looking for more information on tubing, download our Tubing Data PDF. 

Tubing Data PDF

There are 5 main parts to a tube fitting connection.  Nut, back ferrule, front ferrule, and fitting body are all parts that are manufactured to exacting tolerances and standards at Swagelok.  The fifth component, that Swagelok as a manufacturer has no control over, is the tubing. 

Setting the tubing standards

There are a number of standards that apply to tubing depending on material, but we will focus on the stainless steel specs as this makes up the bulk of what we see being used in northern Alberta.

ASTM sets a number of standards for tubing, so when you get your tubing, it is always a good practice to check the lay line on the tubing for the ASTM standard to which it is manufactured.  It should be printed on the tube, along with the heat number for the tubing.

For stainless steel tubing, ASTM A269 or A213 are common grades.  A269 refers back to ASTM A1016 General Requirements, which gives us the following information:

  • 13.1 – Finished tube shall be reasonably straight and have smooth ends free of burrs.
  • ASTM A269 also gives guidelines for the tolerances of the tubing OD. It is +- 0.005in.  Ovality is allowed to be two times the OD tolerance.

Even with the ASTM specs, there is a lack of standards and there can be variations in the quality of the tubing that you get.  Tubing quality really does depend on the integrity and quality consciousness of the tubing supplier. 

Tubing quality checklist

Before installing any piece of tubing into a Swagelok fitting, the installer should take a moment to take a look at the following items:

  • Is the tubing seamless or welded?  If it is welded are there any signs of corrosion or pitting along the weld bead? Can you see the weld bead on the OD?   If there are, it may create issues.
  • What is the hardness of the tubing?  For best performance with a Swagelok fitting, it is recommended that the tubing not exceed a Rockwell hardness of 90 HRB.
  • Make sure the surface finish is free of scratches.  As the tube fitting seals on the OD of the tubing, scratches can result in potential leak paths.
  • Check for ovality of the tubing.  Oval tubing should not be forced into the tube fitting as it may damage some of the components.
  • Check the OD and ID to make sure they are free of burrs.  A burr on the OD can scratch and damage sealing components.  A burr on the ID can get flushed downstream and damage O-rings or other seals in valves, regulators, or other components.
  • Check the wall thickness to make sure it is sufficient for the pressures that the system will see.
  • Check the tubing for concentricity, that is, check that the wall thickness is consistent all the way around the tubing.  You don’t want a thick wall on the top of the tube and thinner wall on the bottom.

If you have any questions about the quality of the tubing you are using, please contact your local Swagelok supplier.  Edmonton Valve has a number of tools that we can use to help improve the overall quality of your tube fitting connections.

For even more information, the Swagelok Tubing Data Sheet has lots of great information and pressure ratings for most common types of tubing.


Additional resources

In a hurry or have a question? Please click here to get in touch - we respond fast! 
Or call 780-437-0640


Topics: Tubing, Fittings