What Valve materials are available and why do you need to consider each of them?

At Kavaata Valves, we provide a variety of materials for ball valves. These valves are important for different industries, as they control the flow of liquids and gases. Read more about the different materials for ball valves here. Ball valves are often used in various processes. The use of ball valves in various industries has meant that several materials have been used in their manufacturing. This blog talks about the different materials of ball valves and what they are used for.

Kavaata ball valves are made from the best materials, and they are manufactured to the highest standards. They are suitable for use in various demanding applications, such as food, biotech, pharmaceutical, chemical, oil and gas, mining, power generation and more.

Choosing the right materials for ball valves is always a challenging issue. You should be well aware of the operating parameters before choosing the material. The most important parameters are – Operating Pressure, Operating Temperature, Type of Fluid or gas flowing and Application.

Ball valves offer a wide range of materials, from plastic to metal to ceramic. Metal ball valves are used the most, and this is the type of valve that we will focus on.

Types of Materials used for Ball Valves

1. Carbon Steel – WCB is a very common material for ball valves, and is often used in both cold and hot water applications. Carbon steel valves are not ideal for use in applications that are exposed to strong acids or bases, as the valves will corrode. Another disadvantage of carbon steel is that it is not ideal for extreme temperatures, and should not be used in temperatures below zero degrees Fahrenheit. WCB (as carbon steel is commonly called) is a type of cast alloy that exhibits good strength, toughness and ductility. It is typically used in structural applications with elevated temperatures and pressures. WCB is an iron-based alloy that is commonly used in a variety of applications including valves, fittings, flanges, pipes and ducting.

2. Stainless Steel – CF8 is not only stronger, but it’s also better in every aspect. That’s why CF8 is used in the most demanding and critical applications. CF8 has superior tensile yield strength than WCB. It also has higher impact strength, lower modulus of elasticity and higher thermal conductivity. CF8 is non-magnetic and has higher heat resistance, so it is ideal for applications with high operating temperatures. CF8 also offers a wider range of chemical resistance. CF8 is compatible with hot water, steam, seawater, molten salt, phosphates and many other chemicals. CF8 is the best choice for your ball valves, and our team can help you find the right solution for your valve application.CF8 is a grade of austenitic stainless steel used in applications where toughness, strength, and corrosion resistance are required in a non-oxidizing environment. It is used in the food, chemical, petroleum, and pharmaceutical industries. The alloy composition of 18% chromium and 8% nickel gives the material a high corrosion resistance. The high chromium content of this grade makes it suitable for many low-temperature applications such as cryogenic storage. CF8 is an excellent material for high-temperature applications where its high strength, toughness and corrosion resistance are required.

3. Stainless Steel – CF8M is a grade of austenitic stainless steel used in applications where toughness and high strength are required in a non-oxidizing environment. It is used in the food, chemical, petroleum, and pharmaceutical industries. The alloy composition of 18% chromium, 10% nickel, and 2% molybdenum gives the material a higher corrosion resistance. The high chromium content of this grade makes it suitable for many low-temperature applications such as cryogenic storage. CF8M is an excellent material for high-temperature applications where its high strength and corrosion resistance are required.

4. Super duplex stainless steel is a type of alloy which has both the characteristics of ferrite and austenitic stainless steel. The various grades contain about 25% of chromium and at least 5% of nickel. Because of its high nickel content, the alloy’s corrosion resistance is very similar to that of the 18-8 stainless steel with the addition of superior mechanical strength and creep resistance at higher temperatures. Duplex stainless steel is highly resistant to chloride pitting and crevice corrosion, but is not as resistant to sulfide stress corrosion cracking, although it is still considered a good choice for sulfide service. It is used in many applications where improved corrosion resistance, high strength, and/or constant magnetic susceptibility is required. It is the usual material of construction for nuclear power plant heat exchangers, process piping, and marine applications. Duplex stainless steel is an excellent material for chemical processing equipment, due to its superior resistance to acidic or caustic environments. It is also used for valves and pumps in the process industry.

5. Hastelloy is a nickel-based superalloy. Hastelloy alloys are resistant to corrosion in many chemicals and at high temperatures. They are typically used in applications such as nuclear reactors, chemical processing, steam boilers, and oil refineries. Hastelloy is widely used in the petrochemical industry and the chemical process industry. Hastelloy alloys are also used in power generation, marine applications, and metal forming operations. Alloys in the Hastelloy family have excellent resistance to many corrosive environments, as well as excellent mechanical properties at elevated temperatures.

We hope you enjoyed our article about various materials used for ball valves. Because ball valves are used in such a variety of industries, we are sure that you can find a valve that will work in your environment. With this knowledge, we know that you can find a ball valve that will work for you and your business. So what are you waiting for?

Visit – www.kavaatavalves.com today to learn more!

Case Study: 6 Way Ball Valve

3 Way L Port or T Port ball valves are used in flow diversion applications. These valves are used extensively in duplex filters and duplex heat exchangers. Here, the valves perform the function of diverting the fluid from one filter or heat exchanger shell to another. Throughout the movement of the ball, when operated, the flow is not interrupted or brought to a halt. This helps to control pressure surge and makes the 3 Way ball valves ideally suited for the application. Two 3 Way ball valves are connected by a common lever in such a way that both valves operate together when a common handle or gear is operated. Sometimes, it becomes very difficult to maintain the collinearity of the two stem axes due to the distance between the valves. In such cases, Kavaata valves provide common levers with flexible couplings to avoid side loading of stems and consequent leakage.

Sometimes, in compact duplex filters, there is a specific need to bring the valve centers closer. This is not possible to achieve with two 3 way ball valves as described above, as it is imperative to have a minimum distance between two valves when they are connected, to accommodate the two stems and the common lever. Here,
Kavaata 6 way ball valves are the only option available. The concept of 6 Way ball valves involves using two tandem 3 Way ball valves. Instead of connecting the two stems of the 3 way ball valves, here the stem and ball of the valve on top drive the stem and ball of the valve below.

In-line inlet and outlet 6 Way valves

A 6 way ball valve is shown in the picture. 6 Way ball valves manufacturing involves very high degree of machining and assembling accuracy. Any misalignment can lead to leakage and increased operating torque. Kavaata valves have made a name for themselves by providing bespoke solutions in 6 Way ball valves to customers. Another variation in the design of 6 Way valves is the In-line inlet and outlet 6 Way valves. The picture alongside shows one such arrangement. Here, the inlet and outlet of the filter are in-line or collinear.

It can be seen clearly that the 6 Way ball valves are very compact and can be used in applications where space constraints exist. One 6 Way ball valve can effectively replace 4 two way butterfly or 4 two way ball valves. In addition, the simultaneous operation eliminates human errors which can creep in while operating 4 valves independently. The variety of 6 Way ball valves, the size options available with Kavaata Valves and the customization is endless and limited only by imagination.

 

Importance of ‘INDUSTRIAL VALVES’ (Case Study)

Industrial valves are very important part of all process industries. Yet, they remain the most neglected partly because they are silent performers and their presence is felt more when they malfunction or break-down. Valves can be compared to traffic policemen who stop traffic, control the flow of traffic or divert traffic. You can only imagine the chaos that would be caused in the absence of a traffic cop. Likewise, valves are required for isolating flow, controlling the flow and for flow diversion. Different types of valves are used depending upon applications. Ball valves and gate valves are used for isolating purposes. Globe valves and needle valves are used for flow control. Three way, four way and six way ball valves are used for flow diversion. Check valves are used for unidirectional flow. Hydraulic valves are a family by themselves.

Each family of valves is further classified by size, pressure class, end connections, number of ports and material of construction. Thus, within one family of valves, say ball valves, the variety of products becomes endless. Hence, most of the valve making companies can focus on one particular variety of valves in one manufacturing facility. The larger multinational manufacturers have grown by taking over specialty valve manufacturing companies, available anywhere. The smaller valve manufacturers co-operate with each other to quote for all types of valves required in a particular project as it becomes practically impossible to manufacture all valves in one facility. This arrangement sometimes leads to delivery delays but the purchasing manager finds it convenient to follow up with one supplier.

Valve manufacturers of repute find it very difficult to quote for project orders by depending upon other valve manufacturers whose product quality and delivery commitments are doubtful. It becomes all the more difficult in case of product complaints which become the responsibility of the supplier who has procured the defective products. Providing repair service can also be a challenge as projects are established away from cities and sometimes have no proper transportation facility. Co-ordination between the supplier of valves, the actual manufacturer of valves, the project consultant, the erection contractor at site and the actual end user/ customer becomes the biggest challenge while resolving technical issues.

The end user must make efforts to procure different types of valves directly from manufacturers to avoid conflict. Though, the efforts required to identify a good manufacturer, the negotiations, follow-ups and other activities increase, it is finally a win-win situation for both parties as the products become cheaper without a middle-man and communication is more direct. The quality of products is better and the trust that the manufacturer will support the end user in case of a rare failure, is implied.

Industrial Valves-Quality Matters

Have you ever wondered how unbranded products are available at very low prices compared to the branded ones? We often purchase those products with our eyes open, fully aware that the products may not perform as expected. But, we love to challenge our luck just as we do when we buy a lottery ticket. This behavior is acceptable for personal goods but for critical industrial products like valves, quality and performance should rate much higher than price. A leader in a sector has to ensure that their product meets or exceeds quality and performance parameters, every time. The costs for material testing, product approvals, product certifications, marketing, brand promotion, quality inputs etc. are factored in to the cost of the final product. An unbranded valve manufacturer, on the other hand, does away with many or most of the critical testing to produce a sub-standard but cheaper product. A cheap
valve exposes the buyer to the following risks:

Quality Matter No.1: Cheaper Material Grade
Some unscrupulous valve manufacturers substitute a cheaper grade of stainless steel, for example SS304 for SS316 to save on material costs. Superficially, it is very difficult for the buyer, to know the difference. In some cases, the cost of the manufactured valve is less than the cost of the proper grade raw material. Obviously, the valve does not perform satisfactorily in the intended application. It often fails prematurely, attracting extra replacement cost, man-hours and process downtime, all adding up to a huge cost of ownership. The loss can be unlimited if there is an accident involving human life, due to the poor quality of raw material.
Quality Matter No. 2: Poor Design
Poor design can encompass a whole gamut of issues like thinner casting sections to reduce weight, weaker components or wrong design features. Thinner sections do not allow for corrosion allowance and hence fail early. Some manufacturers sell “fire safe design” valves which have an additional secondary metal seat, as expected. However, the design is neither tested for fire safe performance nor certified. The prices of these valves is obviously very low compared to branded and certified products. These safety features are brought into play in very rare circumstances during a fire accident and are very important. Buyers should insist on fire safe certification before proceeding to purchase such uncertified products with poor design.
Quality Matter No. 3: Use of Poorly Machined Components
When valve components are poorly machined and are not consistent dimensionally, all the valves manufactured in a batch, do not perform similarly. The operating torques are not consistent and require a larger actuator to operate the valves. Sometimes the valves fail due to ill-fitted components in the assembly. In addition, if spares are procured for replacement in the field, they do not fit which can lead to increased downtime.
Quality Matter No 4: No Testing of Valves
This is the case with many of the valves purchased from traders. The valves leak immediately upon installation. Traders willingly replace the valve but the lost time cannot be replaced. It is clear from the above Quality matters that Quality indeed matters.

Modification to 65FB 3 Way Valve to Make More Space for Flange Nuts

The picture shows a 3 Way ball valve with the bolt heads encapsulated in the square flange. The use of cap screws and the corresponding tapping in the opposite square flange instead of nuts is a unique way to increase the space for nuts.  This arrangement allows more space for flange nuts used at the customer end. This is especially useful where face- to- face distance constraints does not allow the increase in space for nuts.

 

Picture showing Cap Screw Head

Picture showing tap instead of nut

For more information, click on below click

https://drive.google.com/open?id=1a8U1HB-M7Vfo725855AQbdcyAipMPybs

Common Misconception Regarding 150# and 300# Valve Flange Thickness

There exists a common misconception in the minds of end-users of valves, with regard to the flange thickness of 150# and 300# valves. This is due to the fact that the ASME B16.5 standard treats these two pressure class valve flanges differently when compared to the other higher pressure class valve flanges. The flange thicknesses in the case of 150# and 300# valve flanges are required to be in accordance with the flanged fittings table and are lesser than the flange thickness for the corresponding class pipeline flanges. Sometimes, end users are confused as to whether they should accept valves with thinner flanges than the corresponding pipeline flange thicknesses.

The reason for the confusion stems from the fact that the explanation for this anomaly is given in section 6.2.2 of ASME B16.34 standard and not in ASME B16.5 standard. Section 6.2.2 of ASME B16.34 states that “Flanged ends shall be prepared with flange facing, nut bearing surface, outside diameter, thickness, and drilling in accordance with ASME B16.5 requirements for
(a) flanged fittings for Class 150 and 300 valves
(b) flanges for Class 600 and higher valves”

In light of the above, it is important to understand that Class 150# and 300# valve flanges shall follow the flanged fittings table and shall have lesser flange thicknesses compared to the corresponding pipeline flanges.

NON-SLAM CHECK VALVE- NEW PRODUCT FROM KAVAATA VALVES

KAVAATA is proud  to announce our newly developed product NON-SLAM CHECK VALVE. The valve can be supplied in sizes like 2″, 3″ & 4″. The materials of construction are ASTM A216 Gr WCB (CS), ASTM A351 Gr CF8 (SS304) and ASTM A351 Gr CF8M (SS316).

These valves can be used in the following applications:

  • Gas and liquid pipelines – Gas export facilities
  • Water and steam systems – Product tank farms
  • Cooling towers – Gas storage caverns
  • Water treatment – Mine dewatering

Non-slam check valves are also used in similar applications throughout the chemical processing industry, steam condensate systems and in the power generation industry.

One of the primary advantages of non-slam check valves is their ability to effectively prevent water hammer  therefore, eliminate resultant pressure swings, vibrations, and damage.

 

Timely Procurement of Valves- A Challenge for the Project Manager

Procurement of valves for a project presents itself as a challenge to the Project manager. This is because of the variety of valves required in a project- be it ball valves (manual or actuated, floating or trunnion mounted, two way or multiport), gate valves (rising stem, non-rising stem or knife gate valve), check valves (swing check valve, non-slam check valve or lift check valve), globe valves (regular or Y type globe valve), butterfly valves (lug type or flanged type), plug valves (two way or multiport, manual or actuated), hydraulic valve for high pressure, pinch valves for slurry and the list goes on.  Further, there is a classification based on the material of construction (WCB, CF8, CF8M etc.) and end connections (screwed end- BSP, NPT, BSPT, NPTF etc, socket weld end, butt weld end, and flanged end). Flanged end valves are further classified into pressure classes like 150#, 300#, 600#, PN10, PN16 etc. and country wise standards like ASA, DIN, JIS, BS, EN etc. Of course, size of valves range from 1/4″ to 60″ and above- Phew!

The sheer variety of valves makes it impossible for one company to manufacture all types. Unlike hardware items like bolts, nuts, pipes etc. which are normally available ex-stock, it is impossible for any one company to maintain an inventory of all types of valves. Valve requirement, quantity, size, and type, typically undergoes a number of changes as the project implementation progresses. Hence, the final list of valves required is available only as the pipeline work nears the end. This leaves the project manager very less time for the ordering and procurement of valves. The project manager has to rely on his project a consultant’s recommendation for supplier selection or scout for new manufacturers. The tender process, technical and commercial negotiation and final order generation take up a good chunk of the available time.

Valve manufacturers are always at the receiving end as the time allotted for supply is much less than what is normally required. Valve manufacturers knowingly accept L-D Clause terms, like a discount, while accepting an order. Valve industry is not looked upon as a manufacturing entity with its own set of problems and lead time requirements. This is mainly because the ratio of the total cost of valves to the project cost is very small. The fragmented and specialized nature of manufacturing ensures that valve manufacturers remain small compared to the customer size and hence are not accorded any importance.  Valve manufacturing is a batch process and not a continuous high volume process. What is forgotten is that a delay in supply of valves can bring the entire project implementation to a halt and lead to huge losses. Foundries who supply castings to valve manufacturers work under huge time constraints. Sometimes there are casting defects which can undermine the quality of valves. These show up at the very end of the manufacturing cycle at the valve testing stage and brings more misery to valve manufacturers. Rework, rejection or replacements are required which further delays valve supplies. To add to the misery, sometimes, third-party inspection agencies appointed by customers, do not have inspectors available to conduct a timely inspection. This leads to further delays.

In view of the above, it is imperative that project consultants, project managers, and customers allot sufficient time, typically 6- 8 weeks for good quality valve manufacturing.  Some understanding of the typical problems faced by valve manufacturers will go a long way in early ordering for valves and reduce project delays. It is hoped that this post shall help all concerned to  E-Valve.

 

Seat Material Selection in Ball Valves

Seat material selection in ball valves poses a challenge to most end users in the industry. This is because most users are masters of their domain but lack the technical information to make the correct seat material selection. In this blog, we shall present the required information to help such users.

Generally, PTFE (Poly tetra fluoro ethylene) is the most common seat material used in ball valves. This is because PTFE is chemically compatible with most chemicals and has a very low co-efficient of friction. This allows ball valves to be operated with ease. PTFE can work at 69 Kg/ sq. cm in the temperature range -40 deg C to 90 deg C. The maximum temperature this seat material can withstand is 200 deg C at pressures up to 15 Kg/ sq. cm.

For higher temperatures up to 250 deg C and pressures up to 15 Kg/ sq. cm, Carbon Filled PTFE grades can be used. Similarly, Glass-filled PTFE grades can be used for higher pressures up to 100 Kg/ sq. cm at room temperature.

In case of valves for hydraulic applications at room temperature and pressures up to 400 Kg/ sq. cm, POM (Acetal Resin) seats can be used economically.

In applications requiring the seat material to withstand both higher temperatures (150 deg C) and pressures up to 400 Kg/ sq. cm, PEEK seats can be used. Virgin PEEK, as well as carbon filled PEEK grades, are available. However, PEEK seats are very expensive and should be specified only in very critical applications.

For severe service, valves can be supplied with metal seats. Various combination of metal seat types are available for temperature ranges from 350 deg. C to 650 deg C. The advantage of metal seats is that there is practically no pressure constraints. Moreover, these valves can work very well with abrasive media.

KAVAATA valves are manufactured with all the above-mentioned seat materials and can be supplied against specific customer requirements. KAVAATA can supply metal seated valves with Class V and Class VI leakage rates.