American Engineering Trusted Worldwide
Home/Valves & Fittings

Valve Materials: Do There Have to Be So Many?

When it comes to choosing the right valves for your project, there’s a lot to consider. Valves serve many purposes and industries. And within each industry, they have numerous different functions. So while all CPV valves are manufactured to meet or exceed the highest quality standards, they’re not all the same.

Several factors come into play when making a decision about which valve will meet the requirements of the job for which they’re needed. Besides knowing the function or the action it will perform, it’s necessary to know the type of fluid or medium that it will be used for, the temperature of the substance, the pressure and flow rate, and the size of pipes or other equipment it will be connected to.

Armed with this information, you’ll be able to narrow down the options and select the product that will best suit your needs and provide the most return on investment.

One of the most important decisions you’ll make during this process is selecting the materials for the valve body and trim. Valves can be composed of materials ranging from cast iron to bronze to PVC. In valves like the ones CPV manufactures, there are typically two or more different metals in a single valve.

You may wonder why we don’t always use the “best” material for everything. It doesn’t quite work that way.

What’s best for one application might be the worst possible choice for another. And the “best” might not be the most cost-effective.

Factors Affecting Body Material Selection

 Once you know what type of valve you need, the next step is to determine what metal or material will best suit the application.

Let’s look at some factors that will help guide this decision.

Resistance to Corrosion

Corrosion is the act of destroying, weakening, or wearing away a surface. It affects both the exterior and the interior of the valve.

In the external environment, air and moisture can lead to corrosion. In materials such as iron and steel, we see this in the form of rust. Many CPV customers have more than just the usual air and humidity to consider. Their businesses may operate in or near salt water. The harsh external environments to which their equipment is subjected accelerates the rate of corrosion. If you’ve ever owned a vehicle and lived near the sea or in a cold climate where the roads are frequently covered with salt to melt snow and ice, you know that when salt combines with water and air, rust appears even faster on an automobile’s steel parts.

But exterior corrosion in the form of rust isn’t the only concern. When a substance is flowing through a valve, corrosion can occur from the inside as well. The rate and degree of internal corrosion are dictated by the type of substance flowing through the valve. Sweet crude oil for example (crude oil containing low amounts of sulfur), is non­‐corrosive and actually helps to protect the metal surfaces it contacts. Strong acids like sulfuric acid, on the other hand, can eat through some metals in a matter of hours.

Strength of the Material

There are two general measures of strength that play a role in valve material selection. Tensile strength is its stretchability or resistance to breaking when it’s stretched. If it can be stretched a little without breaking, it’s ductile. Copper is an example of a metal with good ductility, which allows it to be stretched into a wire. If a material doesn’t stretch, it’s brittle, like a ceramic plate that shatters rather than bends when it collides with a hard surface.

A valve’s body has to be able to withstand the pressure from inside. That’s where its tensile strength comes into play. A metal such as cast iron may seem like a good choice, but it’s brittle and cracks under too much pressure. In operations where high pressure is a factor, the material used must have good ductility. Knowing the pressure during operation is essential in selecting the right valve material.

Operating temperature also affects a metal’s strength and is another important factor in determining its suitability for a valve. In general, as the temperature increases, the metal softens and weakens. If it’s too cold, the wrong metal becomes brittle. So the temperature limits of the valve material must be aligned with the temperature at which it will be operated.

For example, a low-­‐grade carbon steel can handle 285 psi at 100 degrees F, but that number drops to merely 50 psi at a temperature of 900 degrees F. Long exposure to high temperatures can also change some carbon steels to graphite. Depending on the particular metal, the tolerance range, as in the case of cast iron, may be as limited as ­‐20 to 410 degrees F. On the opposite end of the spectrum, certain stainless steel alloys have a broad range, from as low as ­‐425°F to as high as 1500°F.

Resistance to Erosion

With each component of a valve serving a unique function; and therefore being subjected to somewhat different conditions, special materials are usually required for a valve’s trim (the closure elements or parts such as the stem, seat, and disc). In addition to strength and corrosion resistance, the trim is more susceptible to erosion.

Similar to corrosion, erosion is wear caused by a mechanical action or the repeated application of localized stress. In other words, a substance breaking down a solid material due to pressure and repeated action, rather than a chemical reaction.

Sandblasting is a form of erosion. Dirt or other abrasive particles contained in a substance will contribute to metal erosion.

The effects of erosion are amplified on trim closure elements. As a valve closes, the velocity of the substance flowing through it increases, like putting your thumb over the end of a running water hose to make the water spray out with more pressure. This increased velocity causes wear in the form of erosion.

CPV Manufacturing is committed to making only the best quality valves and fittings. We design them with versatility in mind so that our products are perfect for many industries, purposes, and settings including the harshest of environments. Whatever your needs, you can trust CPV to provide the highest quality products to satisfy them.

Home/Valves & Fittings

So, What’s the Deal With Seals?

Does your familiarity with valves start and end with a dictionary definition? If you’re reading this article, probably not. But just in case, here’s Merriam-­‐Webster’s take on valves:

[Valves are] any of numerous mechanical devices by which the flow of liquid, gas, or loose material in bulk may be started, stopped, or regulated by a movable part that opens, shuts, or partially obstructs one or more ports or passageways.

Frankly, that’s not a bad start. Valves are, in fact, numerous, mechanical and devices. And they do start, stop and regulate flows of liquids, gases and loose materials (e.g., slurries). And yes, movable parts do open, shut or partially obstruct passageways (i.e., piping and tubing).

The truth is, many valves and fittings are highly engineered devices machined to extremely close tolerances—like those CPV manufactures. And integral to any valve’s ability to serve its intended application is its sealing performance. In fact, engineering and specifying the sealing for any valve or fitting’s application is just as important as its overall design itself.

Valves are technically fittings. Though they perform different functions within a system, they do complement each other. And while it’s worth considering them separate categories when purchasing for your application, when it comes to sealing properties, they’re not all that different.

Why Sealing Matters

Whether for a valve or fitting, seals serve one purpose: reduce leaks, whether fluid or gaseous. It’s estimated that roughly 300,000 tons of fugitive emissions (the unintended discharge of gases or vapors) are released annually in the US alone. Inadequate sealing is the root cause, and better sealing is the only solution.

Beyond curtailing fugitive emissions, better sealing technology—like the CPV-­‐developed line of O-­‐SEAL valves and fittings—has other practical benefits. Most notably, high-­‐quality seals extend the service life of the equipment used within an application. In other words, a good seal saves money, time, the environment and, potentially, prevents catastrophic failure.

While beyond the scope of this article, the predominant regulatory standards by which valves are tested and certified to ensure fugitive emission tightness are ISO 15848 in most of Europe, VDI 2440 in Germany and API 622 and 624 in the United States. CPV products meet or exceed the qualifications for all these standards.

Sealing Materials in Use Today

The materials used for mechanically sealing rotary elements of valves (e.g., valve stems) are numerous. Stainless steel, titanium, bronze, aluminum, chromium, various carbons, tungsten, silicon…the list goes on and on. But just as important, if not more so, are the flexible parts of these components.

Flexible parts are often made from synthetic elastomers, which are polymers with elastic properties. Some typical examples in use today are nitrile, chloroprene, ethylene propylene and butyl rubber. And then there’s graphite, which is a ubiquitous packing material, and polytetrafluoroethylene (PTFE, or Teflon, made famous by your nonstick cookware). Again, the list goes on and on, and even includes natural vegetable fibers like jute and cotton, along with human-­‐made fibers like acrylic and melamine.

Better Seals for Challenging Conditions

When it comes to properly sealing valves and fittings, some industrial applications pose more challenge than others. Industrial gas, petrochemical and shipbuilding, for instance. All rely on high-pressure systems, and all happen to be the primary industries for which CPV manufactures.

CPV is perhaps most well-­‐known for our O-­‐SEAL line of valves and fittings, designed to meet the stringent requirements of the US Naval force. In fact, CPV outfits every US Navy surface vessel and submarine in operation today. The O-­‐SEAL line has seen success outside of shipbuilding, though. Gas refineries, for example, rely on its leak-­‐proof performance, safety and reliability.

Specific to the smaller valves found in the processing sections of refineries, the O-­‐SEAL limits the release of fugitive emissions to incredibly low levels, as has been verified by independent laboratory testing. The design has a flexible O-­‐ring made from ethylene propylene, polyurethane, Chemours Viton™ or, in certain cases, a custom solution. The O-­‐ring is recessed within a close-­‐tolerance groove on either side of the valve’s flat-­‐faced union ends, offering slip-­‐in, slip-­‐out convenience. The bubble-­‐ tight seal this creates withstands heavy vibration and pressure surge far better than gasket or metal-­‐to-­‐metal types seals.

Depending on the seal material selected, these valves will function from −65°F (−54°C) to 400°F (204°C). They also handle the most elusive gases such as helium and hydrogen.

The entire O-­‐SEAL line of shut off, needle, check and relief valves are rated for vacuum to 6,000 psi (413 BAR) in liquid or gas service. But they’ve been tested to much higher pressures without failure. CPV’s Mark VIII O-­‐SEAL fittings, for example, when heat sealed into a system by welding, orbital welding or brazing, can sustain in excess of 16,000 psi. Just take a look at the picture to the left and the chart below. In this test, Mark VIII O-­‐SEAL fittings were brazed—the most basic heat-­‐sealing technique, requiring only a handheld propane torch—to brass, copper, steel and stainless steel tubing. In every test, the tubing failed while the Mark VIII fittings remained intact. And in every test, the burst pressures far exceeded the fitting 6,000 psi pressure rating. You’ll notice the test using 1/16” stainless steel tubing with a steel Mark VIII threadpiece had to be terminated at a whopping 28,000 psi!

Now, while we absolutely discourage our clients from taking CPV’s valves and fittings beyond their official maximum pressure ratings, this is an undeniably impressive performance.

Sealing Up

Without adequate sealing, even the best-­‐engineered, machined-­‐to-­‐the-­‐finest-­‐tolerances valves are useless to the industries that rely on them. For more than 100 years, CPV has been at the forefront of all of the above. And we have the numbers to back that up.

Home/Valves & Fittings

And the Medal Goes to: The Advantages and Disadvantages of Plastic Valves

And the Medal Goes to: The Advantages and Disadvantages of Plastic ValvesPlastic valves have become increasingly popular for certain media and applications. And while CPV doesn’t manufacture plastic valves—they lack particular qualities necessary to the industries we serve—we can still discuss their advantages and disadvantages when compared to metal valves. You might think the title of this article is a spoiler if you’re fond of rhymes. Is it? You’ll need to read on to find out.

The plastic valve industry has been around for little more than a half-­‐ century. So it’s relatively new, at least when compared to the metal valve industry, which likely originated in ancient Rome. There, valves made from bronze were instrumental in the development of canal systems that were, by every account, far ahead of their time. Still, despite the short history of plastic valves, they’ve come a long way.

Grading Plastic

Not all plastic resins are created equal; they come in various grades that are more or less suited to different applications. Mention plastic valves to most people, though, and flimsy ball valves probably come to mind. You’ll find these controlling water flow to swimming pools or irrigation systems, for example. They’re generally made of PVC (polyvinyl chloride), which is the most common plastic valve material in use today.

The best PVC valves are typically rated for pressures up to 150 psi at 75° F. Their maximum safe operating temperature is 140° F, but pressure ratings will have fallen substantially with the increase in heat. A derivation of this material, chlorinated PVC, can handle temperatures up to 180° F.

PVC alternatives developed to meet higher temperature and pressure ratings include PVDF (polyvinylidene difluoride), PTFE (polytetrafluoroethylene) and PEEK (polyether ether ketone). PVDF valves can be designed to achieve pressure ratings up to 230 psi. PTFE can safely manage temperatures up to 300° F. PEEK is the winner here, rated up to 500° F. For all these materials, as temperature and pressure ratings rise, so do prices. So while PEEK is a high-­‐performance polymer, it is also cost prohibitive for many applications. Metal valves, on the other hand, can perform as well as or better than PEEK at a lower cost.

Considering plastic valves’ limitations, why manufacture them at all? There are a few primary reasons end users or system engineers may choose plastic. For less critical applications, it can be inexpensive. It’s also lightweight, which means reduced shipping costs. And even for more critical applications, like the manufacturing of corrosive chemicals or semiconductors, the highest quality plastic valves approach the reliability of their metal counterparts. Plastic valves do have their niche markets.

Where Metal Shines

For nearly every application plastic valves perform well, there exist metal counterparts that perform as well or better. Metal valves have stood the test of time—for a very long time. And just as certain plastic materials have been developed to serve different applications, the same is true of metal.

CPV manufactures high-­‐quality valves made from bronze (though, without the high lead content that some surmise hastened the fall of the Roman empire), brass, stainless steel and Monel (a highly corrosion-­‐resistant nickel alloy). All go through extensive machining processes to ensure perfect fit and function, and lasting durability. In fact, some CPV-­‐manufactured valves have remained in service for as long as plastic valves have existed. That’s pretty incredible.

With a media as innocuous as water, some might be attracted to plastic valves for their lower cost compared to, say, bronze or stainless steel. But even water can damage plastic valves. A pressure surge caused by the abrupt stop of flow—as when a valve shuts quickly—can cause what’s called fluid hammer. Water, being incompressible, is especially prone to this. The shockwave caused by the pressure surge could not only destroy the plastic valve, but could potentially damage the entire application.

The valves and fittings CPV manufactures are used primarily in the petrochemical, industrial gas and shipbuilding industries. In fact, every US Navy surface vessel and submarine has been outfitted with CPV components. These industries rely on our highly engineered, expertly machined products to just work. In critical applications, failure is not an option. Some plastic valves may seem like inexpensive alternatives to their metal counterparts. But take into account the long-­‐term reliability of quality metal valves and fittings, and the total cost of ownership is in metal’s favor nearly every time.

Long Story Short

Metal valves are adaptable, strong, dependable and suitable for more applications than plastic valves. So, let’s finish where we started off.

And the medal goes to…metal.

Home/Valves & Fittings

The Advantages of Replacing a Soft Goods Kit

The Advantages of Replacing a Soft Goods KitA failing valve is not just troublesome, it is a potential weak link in an otherwise robust chain. Some of the smallest parts within an already compact valve are those most crucial to a system’s overall performance—they have the power to ensure smooth operation or result in catastrophic failure. It is essential, then, to maintain the performance of your valves by replacing soft goods both when necessary and proactively. And you should always follow the practice of installing soft goods kits that are designed and manufactured according to the specifications set forth for the exact valve you are servicing. Read on to learn more about the advantages of using soft goods kits.

Why Replace Soft Goods?

Soft goods need to be replaced for two primary reasons. The first and most urgent is when a valve’s sealant is leaking. Visible leakage is a clear indicator that the valve cannot function properly, and threatens the entire application’s reliability and the safety of the equipment operator.

The second reason soft goods are replaced is simply because it is smart to change them at set intervals, even if there is no noticeable damage. Employing such preventive measures ensures continued, healthy and reliable valve operation.

Soft Goods Kits and Their Benefits

Soft goods kits are the most cost-effective solution for repairing faulty valves. Rather than having to purchase a new valve assembly, it is significantly more economical to buy a kit designed to repair your otherwise serviceable valve. In many situations, the stem seal, O-Rings and packing are typically the only portion of the valve that needs to be replaced. In this case, by isolating and repairing the root problem, you now have a well-functioning system that did not necessitate the replacement of the entire structure. This stretches the lifespan of an already long-lasting valve and is more practical than starting from scratch with a new product.

Ensuring your valves operate at peak performance saves time and expense by eliminating or reducing the likelihood of unplanned repairs. Key team members are now freed to focus on other aspects of process outcomes, resulting in increased efficiency and further cost reductions. Soft goods kits are valuable because of their assurance of reliability, their ease of use in fixing an isolated problem and their time-saving convenience.

Where to Select a Soft Goods Kit

Soft goods kits include all necessary components to replace a leaking—or functioning, but older—valve part. Kits typically contain many possible replacement parts, as well as the tools needed to remove the original part. Exactly which replacement parts and which tools will depend on the original valve design’s specifications.

Individual manufacturers sell their own soft goods replacement kits. The specifications of soft goods are set by the original designers of the valve depending on the application for which they will be used. Factors like temperature and exposure to other environmental conditions, in addition to the chemicals and compounds they will be in contact with, influence every decision behind the engineering of soft goods.

For this reason, it is essential to choose a kit supplied by the valve’s original manufacturer. This ensures the same reference number, and reduces the risk of replacing parts with different filling percentages, which are, essentially, the recipes that determine the makeup that fulfills the application requirements of the soft good. It also guarantees that the new parts will not be counterfeit, and are exactly suited to your valve’s application.

Consequences of Using the Wrong Soft Goods Kit

While a faulty valve may seem to perform well with a nonspecific replacement part, it will not function to its fullest potential because it is not precision-matched to the original engineering specifications. In larger and more critical applications, it is especially important to certify that each individual part works correctly, and this can only be accomplished by using materials sourced from the original manufacturer.

It can’t be overstated: replacing soft goods with cheap or illegitimate alternatives is a danger not just to the result of the application, but to the workers controlling and being exposed to these products. The consequences of a valve error extend well beyond the valve itself. Every product and every person working with and relying on that valve will be at risk. This is especially true in high-pressure environments. To prevent failure, it is essential to replace soft goods as soon as trouble presents itself or, better yet, according to a preventive maintenance schedule.

Selecting the Right Soft Goods Kit with CPV

CPV offers soft goods kits for our durable O-SEAL and G-Series product lines. Valves from each line provide long-lasting performance, and should be checked for maintenance at regular intervals, especially if they are used frequently or in extreme conditions. The following sections will review soft goods kit selection and installation for our O-SEAL products.

An O-SEAL valve’s O-ring is recessed within a close-tolerance groove on each of the flat-faced union ends for slip-in, slip-out convenience. This creates a bubble-tight seal that can withstand heavy vibration or pressure surges far better than a gasket.

The soft goods in the cartridge are removable and are specified in different materials for different applications. The software makeup is determined by its compatibility with the liquid or gas it will come in contact with and the temperature range of the application. Because the cartridge is easily removed from the valve for maintenance or replacement, the cost of purchasing a new valve can be avoided. In most cases, the cartridge can be served off-line with a new soft goods kit for re-use another time.

While most stem seals are made of rubber, O-SEAL stem seals are fabricated from polyurethane, Viton and ethylene propylene. Please see the chart below to determine the proper material grouping shown across the top of the chart. Read down the column and select the Kit Number from the row matching the valve size or Dash Number.

For example:

A ½” 380-3 Globe valve requires a soft goods kit. The valve is used in compressor air service, and the compressor is lubricated with a petroleum-based oil. The materials listed in the first column under Material Grouping are satisfactory for this service. Continue down this column to the line for Dash No. -3 (½” pipe size) to determine that the Kit Number is 003803.

The Advantages of Replacing a Soft Goods Kit

How to Use Our Soft Goods Kit

If a seal needs to be replaced, meet our leakproof standards by using the “U” cup installation tool developed exclusively for CPV applications. An inexpensive choice, the “U” cup is a simple solution that replaces stem seals in less than a minute. By compressing the outer sealing lip and expanding the inner lip, the kit makes it easy to slip the “U” cup stem seal over the valve stem. Once the stem seal is properly installed on the valve stem, it can be easily inserted into the bonnet gland and secured without damaging the critical edges of the seal.

For step-by-step instructions on how to install “U” cup steam seals in CPV O-SEAL system valves, see the image below:

The Advantages of Replacing a Soft Goods Kit

 

 

 

 

 

 

 

 

 

 

 

 

 

In Conclusion

Soft goods kits are an inexpensive method for repairing, rather than replacing, a faulty valve. Because every valve has specific material requirements, it is best to choose a soft goods kit from the original manufacturer, ensuring the exacting specifications and application suitability. Again, this is especially true for the most critical applications. And while soft goods kits can be used when a valve is noticeably leaking, it is wise to change out soft goods according to a predetermined preventive maintenance schedule to ensure prime valve functionality and worker safety.

CPV offers soft goods kits for both our O-SEAL and G-Series valves. For more information about CPV soft goods, or any other general queries, please visit cpvmfg.com or contact sales@cpvmfg.com.

Home/Valves & Fittings

On Counterfeit Valves and Fittings

Counterfeit Valves: They Fake It Till They Break It

On Counterfeit Valves and FittingsFrom iPhones to watches to shoes and apparel, it seems that for every legitimate product on the market, there are twice as many cheaply made counterfeits. And believe it or not, industrial valve manufacturers have not remained immune to this problem. The market is saturated with counterfeit valves and fittings, but it can be difficult to know how many are out there. Many simply go undetected, only recognized for what they are once they fail. And even when counterfeit valves or fittings do fail, under-reporting of these incidents seems to be somewhat prevalent. While most end users whose valves have failed were probably unaware the products they used were counterfeits, others may forego reporting for risk of damaging their reputation or being seen as negligent.

There Are Counterfeits, and Then There Are…Counterfeits

We should note that when we discuss counterfeit valves, there are two categories they generally fall under. Manufactured fakes are what a consumer typically thinks of as a counterfeit. These are analogous to those Louis Vuitton handbags going for 1/10th their market value.

The other type of counterfeit valve is one that has been refurbished by a dubious supplier looking to make an easy buck. If a manufacturer or legitimate supplier was in the midst of overhauling or renovating its plant, for instance, it might have sold off older valves as scrap. Regardless of the motives, problems can arise when those valves are then processed to make them once again operational. Too frequently, forged manufacturer tags are affixed to the rebuilt valves in an effort mislead end users. Unless a valve has been refurbished, retested and recertified by an OEM, it’s probably worth considering this type of counterfeit just as dangerous—and in some cases more dangerous—than a manufactured counterfeit.

Counterfeit valves and fittings can be so challenging to spot that they’ve been discovered in chemical processing plants and even nuclear power plants. That’s a scary thought, and, thankfully, those counterfeits were found before they had a chance to fail. Others have been less lucky, though, like a paper mill that decided to cut costs by purchasing remanufactured valves from a third-party supplier. The supplier neglected to verify the valves’ wall thicknesses—something that should really be done by an OEM, who knows where to measure for critical dimensions—resulting in a catastrophic failure after the side of the valve blew out.

Shut off the Flow of Counterfeits

So, how can you avoid purchasing counterfeit valves and fittings? Know your suppliers well, or purchase directly from the established OEMs. When dealing with suppliers, consider integrating into your contract language that holds them responsible for counterfeits that enter their supply chain and make into your application. For instance, your supplier might receive a large order from another client, forcing them to seek out a new source they may be less familiar with.

Beyond that, it’s worth becoming familiar with how to spot counterfeits. Depending on the effort that has been made to hide the counterfeit’s true nature, this can be challenging. For the simpler counterfeits, follow a few of the suggestions below from the Department of Energy’s Health, Safety and Security Office of Corporate Safety Analysis. Below is a sampling taken from their “Suspect/Counterfeit Items Awareness Training” manual.

  • Used component appearance, including signs of weld repairs, outer surface scratches, wrench marks on valve packing glands, nuts and bolts, different types of hand wheels on valves from the same manufacturer and certain parts looking newer than others
  • Suspicious or inadequate packaging, including the use of foreign newspapers as packing material
  • Components with no markings, or those missing important designations like pressure class ratings
  • Components with too many markings (e.g. an excess of certification logos like “UL,” “FM,” “CGA” and “AGA” all appearing on one valve body is not normal; one or two logos plus “ANSI” or “ASME” is)
  • Evidence of tampering, including ground off logo marks, ground off casting marks with stamped marks in their vicinity and overlapping stamps
  • Old or worn nameplates, or nameplates that look newer than the components themselves

In Conclusion

As you can probably tell, the time that goes into detecting counterfeits probably negates any cost savings a supplier or end user might have otherwise been glad to find. Yes, counterfeit products are inexpensive. The irony is, their long-term—and even their short-term—cost is far greater than the price of a highly engineered, expertly crafted valve made to last.

Want to be sure you’re getting the real deal? Buy direct from the OEM, or require your supplier or contractor to do the same. Do CPV valves cost more than counterfeits? Of course. We engineer them to exacting standards. They’re made to last. Because ultimately, we’d rather explain the price of our valves to our customers once than apologize for their quality forever.

Home/Valves & Fittings

On the Importance of Valve Lubrication

On the Importance of Valve LubricationWhether for use in valves or otherwise, whether organic or synthetic, lubricants always serve the same purpose: reduce surface-to-surface friction. In valves, however, proper lubricant use and maintenance is especially important given the extremely tight tolerances to which they are manufactured and the often demanding conditions under which they are operated.

A valve’s most basic function is to control the flow of liquids, gases or slurries. But a properly functioning valve must not only control flow, it must prevent leakage and protect itself from degradation over time. This is where lubricants play a vital role. Even the simplest of check valves—those which contain a hinged flap free to move in one direction and not the other, thus preventing backflows—require the right lubrication for their application and a preventive maintenance schedule to ensure optimal performance.

CPV’s valves are typically more complex, always manufactured to the highest possible tolerances and are employed across many different applications. For these reasons and others, we never neglect the importance of proper lubrication. We encourage every client to specify which lubricant they need for their application. And if they can’t, or aren’t quite sure, our engineers are glad to provide those specifications to them. We prefer to ship every valve with properly lubricated seals and stem threads to promote an easier integration within the prescribed application.

How specific do lubricants get? Put simply, very. For example, while many lubricants are petroleum-based—there are many base groups designated by the American Petroleum Institute and even more viscosities—we wouldn’t recommend them for an application that involves the transport of oxygen, lest you risk the possibility of ignition. The inert qualities of polytetrafluoroethylene (PTFE)-based lubricants, on the other hand (PTFE is what your nonstick cookware is coated with), would be appropriate for such an application. A solid lubricant like PTFE is often suspended in an equally inert grease compound to serve this purpose, or, in other applications, applied as powder directly to a valve’s moving parts.

The various types of lubricants and their applications is beyond the scope of this particular article. It is important, though, that we discuss the crucial role  valve lubricants play in the context of preventive maintenance.

Preventive maintenance is just what it sounds like. It is a series of measures taken to ensure failures, catastrophic or otherwise, can be prevented with reasonable degrees of certainty. When a well-made valve fails, it is almost always because proper preventive maintenance procedures have either not been established or correctly followed. There is no single preventive maintenance schedule to suit all applications. If a customer is unsure, a valve manufacturer should be more than willing to help. A long-lasting, well-functioning valve is, after all, in that manufacturer’s best interest. CPV customers know that our engineers and technicians are always prepared to recommend best-practice maintenance procedures.

In many cases, servicing a valve may be as simple as opening its casing and coating its stem with the appropriate lubricant. Other valves are designed with lubrication ports, facilitating the direct injection of a lubricant without having to open the valve for maintenance. As always, be sure you are using the right lubricant for the job.

To be perfectly clear: don’t wait for a valve to show signs of wear before re-lubricating. Being proactive with a preventive maintenance schedule means you can avoid being reactive to a catastrophic failure. So lubricate well. Lubricate often. You’ll save yourself time, money and headaches throughout the lifecycle of your valve.

Home/Valves & Fittings

What to Do If a Pressure Relief Valve Is Leaking

Pressure relief valves ensure efficiency and safety in many chemical, oil, and gas plants, but they’re susceptible to leaks. If a pressure relief valve is leaking, systems can become overpressurized and even fail, especially if the valve isn’t addressed or repaired quickly.

To help you prevent system issues and dangerous overpressure conditions, here’s your guide to what to do if a pressure relief valve is leaking.

Shut Down the System When a Valve is Leaking

What to Do If a Pressure Relief Valve Is LeakingWhen a pressure relief valve is leaking, the first and most important thing you need to do is shut down the system. Leaking pressure relief valves can’t regulate the overall pressure within the pipelines. This can cause overpressure conditions, which can lead to system failure and, in some cases, system explosions and fires.

So make sure that you shut down the system when you detect a leaking pressure relief valve to prevent serious system issues and dangerous conditions.

Determine the Cause of the Leak

When you shut down the system, carefully examine the pipelines and the valve itself to determine the cause of the leak. This will help you figure out exactly what you need to do to repair it.

Pressure relief valve leaks usually occur when the valve isn’t properly seated or when the seal is broken or damaged. Leaks can also happen when the pressure relief valve is operating too closely to the set point.

Perform the Necessary Repairs

What to Do If a Pressure Relief Valve Is LeakingAfter you’ve determined the cause of the leak, you can start repairing the valve. According to federal leak detection and repair standards, companies have five days to perform the first repair attempt.

For the first repair, you should tighten or replace the bonnet bolts and tighten the packing gland nuts. You want to make sure that you follow manufacturer repair guidelines for the first repair.

If the valve isn’t completely repaired after your first attempt, you have up to 15 days to perform any additional repairs according to the EPA. If the valve still isn’t fixed, then you can either replace the pressure relief valve or wait until the next shutdown cycle to do more repairs.

Prevent a Leaking Pressure Valve

When the pressure relief valve has been fixed or replaced, it’s important to take the necessary steps to avoid leaks in the future. To do that, consider implementing a leak detection and repair (LDAR) program for your company.

An LDAR program will help to train workers on everything they need to know about detecting and repairing a leak before system damage can occur. It will also help you monitor valves more efficiently so you can spot leaks faster and spend less money on overall valve repair and maintenance costs.

To learn more about pressure relief valves for your company, read our post on how to choose the right pressure relief valve. 

Home/Valves & Fittings

How Does a Check Valve Work?

Check valves are responsible for ensuring proper flow within a fluid system. Also known as non-return or one-way valves, check valves are specifically designed to prevent reverse flow within a pipeline. But how does a check valve work?

Check Valve Function and Operation

How Does a Check Valve WorkTo really understand the question: how does a check valve work, you must first understand how they’re constructed. Most check valves are made with a body, seat, disc, and cover. Other types of check valves may come with additional parts like a spring, ball, stem, or hinge pin depending on their design.

Check valves are controlled based on a system’s flow velocity. Once the system reaches the cracking pressure or the minimum upstream pressure needed for the valve to operate, the disc will lift and allow the fluid to pass through. If the fluid pressure decreases or if the flow direction starts to reverse, the disc will automatically close the valve to keep fluid from flowing through. This helps to prevent backflow.

Since check valves rely on the pressure and flow velocity of the fluid in the system to operate, they can usually work without any automation or human interaction. With that said, check valves aren’t typically designed with any form of exterior operation mechanisms like a lever or handle.

Check Valve Applications

Now that you understand the basics of; how does a check valve work, we review the common applications. Check valves are commonly used for industrial pumps and fluid systems in the oil and gas industry. Chemical and power plants also use check valves to prevent reverse flow in advanced machinery. On top of that, check valves can be installed in many process systems to keep fluids of different pressures separated.

Check Valve Selection

How Does a Check Valve WorkWhile all check valves are designed to ensure proper flow direction, they’re not all the same. There are many types of check valves, and each is intended for specific application and service conditions.

The ideal check valve should be made with the material that’s compatible with the type of liquid or gas you’re working with. You should also make sure that you select the appropriate type of check valve (e.g. spring-assisted in-line check valve, silent check valve) for the application.

How Does a Check Valve Work Takeaways

Most importantly, you need to ensure that the check valve you choose is the correct size for the application, not the line size. Selecting a valve that’s sized for the application keeps the disc stable on the internal stop when the valve is open or closed. This helps to keeps the disc from fluttering and extends the valve’s overall service life.

In this article, you learned: How does a Check Valve work? To learn even more about how check valves work and how to select a check valve for a specific application, read our post discussing the basics of a check valve.

 

Home/Valves & Fittings

How Does a Needle Valve Work?

Like most valves, needle valves are responsible for the safe and efficient operation of industrial machinery. They control the flow rate of fluid within a pipeline, but how does a needle valve work?

To give you a better understanding of these common industrial valves, here’s everything you need to know about your question how does a needle valve work?

Needle Valve Construction and Design

Needle valves are similar to shutoff valves. They’re used to start, stop, and regulate the flow rate within a pipeline.How Does a Needle Valve Work

However, needle valves are designed differently. Unlike shutoff valves, needle valves have a long, tapered, needle-like point at the end of the valve stem. This is often referred to as the plunger.

These valves also have a handwheel or a small handle located on the plunger that controls the position of the plunger.

The valve’s needle-like plunger fits into the seat. Because of this unique design, a needle valve can precisely and accurately control how much fluid passes through the valve.

How Does a Needle Valve Work

Needle valves can operate manually or automatically. Manually operated needle valves use the handwheel to control the distance between the plunger and the valve seat. When the handwheel is turned in one direction, the plunger is lifted to open the valve and allow fluid to pass through. When the handwheel is turned in the other direction, the plunger moves closer to the seat to decrease the flow rate or close the valve.How Does a Needle Valve Work

Automated needle valves are connected to a hydraulic motor or an air actuator that automatically opens and closes the valve. The motor or actuator will adjust the plunger’s position according to timers or external performance data gathered when monitoring the machinery.

Both manually operated and automated needle valves provide precise control of the flow rate. The handwheel is finely threaded, which means it takes multiple turns to adjust the position of the plunger. As a result, a needle valve can help you better regulate the flow rate of fluid in the system.

Needle Valve Uses

Needle valves are commonly used to control flow and protect delicate gauges from damage caused by sudden pressure surges of liquids and gases. They’re ideal for systems using lighter and less viscous materials with low flow rates. Needle valves are usually used in low-pressure hydraulic systems, chemical processing, and other gas and liquid services.

Shut off Needle valve

These valves can also be applied to high-temperature and oxygen service based on their materials. Needle valves are usually made of stainless steel, bronze, brass, or metal alloys. It’s important to choose a needle valve made with the material that’s best suited for the service you need. This will help to preserve that valve’s service life and keep your systems running smoothly and safely.

Now that you learned the basics to the common question; how does a needle valve work? Learn more about the function of needle valves and how to choose the appropriate needle valve for a particular application, by contacting CPV Manufacturing.

 

Home/Valves & Fittings

Valve Repair & Maintenance Safety: Important Topics to Address

Safety should be your company’s top priority. But as the industry continues to evolve, it’s getting more difficult for businesses to promote valve repair and maintenance safety in their plants. Fortunately, understanding and communicating vital information can ensure peace of mind on the production floor.

To help you better promote valve repair and maintenance safety for your company, here are a few important topics you need to discuss with your staff.

Training for Proper Maintenance and Repairs

valve repairTraining is one of the most important aspects of valve repair and maintenance safety. However, finding experienced and properly trained workers can be difficult as the valve industry continues to grow.

With that said, you need to make sure that you provide employees with the necessary training to ensure safety, especially when repairing and maintaining valves. When your workers operate machinery and other industrial equipment without proper training, there’s a higher chance of experiencing system failures and workplace injuries.

Teaching primary valve information is a good place to start when training employees. From there, take the time to educate them on the latest maintenance and repair systems and technologies as well as standard protocols and procedures. Most importantly, make sure that they have all the tools and resources needed whenever they must repair or maintain valves offsite.

Leak Prevention and Repairs

Pressure relief valveEven with new technologies and design upgrades, leaking valves are still one of the biggest safety concerns in many industrial plants. Leaks of any material can put the workers and the facility in danger and cause environmental damage. Fortunately, new standards and EPA actions are working to reduce the risk of valve leaks and fugitive emissions and ensure safety in the workplace.

Both the ISO and the API have issued many different standards to ensure safe, leak-free valve operations. Both parts of the ISO 15848 standard require more stringent valve testing procedures to minimize and control valve leaks as well as fugitive emissions. The API 622 standard and the API 624 standard address valve leaks and fugitive emissions by adding stricter valve testing and packing requirements.

It’s important to discuss these regulations and standards with workers to make sure that all valves are maintained properly for a leak-free and safe performance. And as always, take the time to provide employees with the proper training needed so they know exactly how to maintain and repair valves safely.

Key Valve Repair & Maintenance Safety Tips

Above all, you need to discuss and remind workers of key valve safety tips. This includes making sure that they’re aware of potential hazards and basic procedures for valve maintenance and repair.

While this does seem like it should be common sense to trained valve professionals, employees can forget. They can also choose to ignore these tips in favor of repair and maintenance methods that are easier but not necessarily safer. So always discuss basic valve safety procedures to keep everyone on the production floor safe and protected.

The valve industry is changing, but safety should always be your company’s number one priority. So take the time to discuss these important topics with your employees to ensure safety and peace of mind at your plant.

Contact CPV Manufacturing to learn more about our high-quality control standards to offer the safe and reliable valves and fittings.