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Introductory LINUO Valves Presentation

Here is a slideshow introducing LINUO ball, gate and butterfly valves. It includes history, capabilities, and comparisons to major competitors.

Key design features and improvements to traditional control valve designs are outlined and presented.

A High Quality, Low Cost Ball Valve for Process Requirements Up to 450°F

LINUO DM2020 Ball Valve

The 2-PC LINUO Maxflow DM2020 ball valve 150/300 flanged, soft seated direct mount ball valve is a well engineered manual valve that makes automation easy.

The valve is available in Class 150 and Class 300 flanged valves, with ISO Mounting Pads. Available sizes 1⁄2” - 10” with full port, 2” - 10” with regular.

The LINUO ball valve is direct mount for simple automation. Square stem means no bracket nor coupler required! Bracket sets available if desired.

The valve’s low torque means smaller actuator and smooth operation. TFM seats are standard. Suitable for a wide range of applications.

Bi-drectional shutoff to class VI. Dimensions to ASME B16.5 for flanges, B16.10 for face to face.

Ball Valve Features:

• SIZES 1⁄2” through 10”
• 150# or 300# Flanged
• BI‐DIRECTIONAL Shutoff
• DIRECTMOUNT
• FIRESAFE Design
• FULL Port or REG Port
• ANTI‐STATIC Design
• BLOW‐OUT Proof Stem
• LOCKING Lever Handle

Valves 101

Valves are mechanical devices that control the flow and/ or pressure within a system or process. They are normally essential components of a piping system that conveys liquids, gases, vapors, slurries etc. Valves are the controlling element in any fluid-handling system. They should be properly selected and cared for to give the best service at the lowest cost.

Different types of valves are available: gate, globe, plug, ball, butterfly, check, diaphragm, and control valves. Each of these types has a number of models, each with different features and functional capabilities. Some valves are self-operated some manually operated or with an actuator or pneumatic or hydraulic is operated.

Linuo Knife Gate Design Advances

The Linuo knife gate is an economical, high performance knife gate valve used in pulp and paper making, refining, wastewater and water treatment, mining, and chemical fiber industries.

It has the following advanced features:

1) A super thin body design and compact construction, providing easy installation.

2) The seats movable design with a spring-loaded O-ring serves to provide self-compensation to normal seat wear, resulting in long term service life. Excellent seal tightness is upheld throughout a prolonged life cycle. Metal seated, EPDM seated and PTFE seat designs are available for various process conditions.

3) The disk bottom provides a knife shaped design with strong cutting force, particularly applicable for pulp media. The disk guide is hard chromium plated after a perfect surface grinding allowing high abrasion and corrosion resistance.

4) PTFE guides insure tight gate to body contact with low friction and no damage to the gate. Small machined transitions at the port bottom prevent residue build-up and reduce downtime.

5) A variety of port designs are available for various process conditions, such as 3 port, triangle port, hexagonal port, and others.

6) The knife gate valve can be mounted with pneumatic and electric actuators control systems for used in automatic control systems in a variety of industries.

Check out this video about the Linuo Knife Gate valve:

Basic Information on Trunnion Ball Valves

A trunnion ball valve is a valve where the ball is physically supported in the body and kept directly in-line with the valve stem. In a trunnion design, there is a single, consistent centerline between the ball and the stem. When under load, the ball does not change position or get pushed or in either direction. A seating surface inside the valve supports the ball, handling the pressure and managing the end loads.

The valve seats on either side of the ball have spring loading on the ball, thus making the trunnion ball valve a true bi-directional sealing ball valve.

For use in severe service, where a metal seated trunnion ball valve is required, seat selection is critical. The physical characteristics of the seat must be able to withstand the application conditions (such as elevated temperatures). Therefore, elastomers or “soft seats” like Viton or PTFE should not be used.

For critical applications a constant, static seal between the seat and body with a dynamic seal between the seat and ball is needed. The seal between seat and body must be a temperature tolerant material such as Grafoil or the like, to withstand the elevated temperatures. The dynamic seal between seat and ball is metal-to-metal, with a variety of hard coating materials such as Hard Chromium, Nickel Boron, Tungsten Carbide, Tungsten Chromium Carbide, or Chromium Carbide.

The valve seat is spring loaded on the ball via upstream pressure providing better sealing on the upstream side of the ball. Trunnions hold the ball in place and the valve seat positions to tightly seal the ball.

Knife Gate Valve Design and Application

Linuo knifegate valves are linear shut off valves that are light weight with compact construction. Valves are available as manual with handwheel, or can be automated with pneumatic cylinder  actuator for remote operation. The arc shape of the gate of our knife gate valve is designed to be particularly suitable for cutting off fluid containing fiber or suspended particles, so the knife gate valves are ideal for many applications in the process industries of Pulp & Paper, Wastewater Treatment, Mining, Sugar Making, and Chemical Processing.

Linuo Stainless Steel Segment Valve Saves Time, Money, Space

Linuo Direct Mount
Segment Valve

Linuo is now offering direct mount segmented stainless steel, flanged control valves.

"Direct mount" refers to how the valves connect to the actuator via a standard bolt pattern without requiring any additional hardware such as a bracket and coupling.

Linuo segment valves have always been able to drop in line (replace without modification to the process connections) with many competitive segment control valves. Now, Linuo provides a lower profile control valve package.  Space savings in process piping is always a good thing. Additionally, the direct mount valve eliminates the need of a bracket and coupling which makes the Linuo valve that much more competitively priced when compared to other segment control valves in the market. For more information visit www.linuovalves.com.

Why Choose a Trunnion Mounted Ball Valve (TMBV)?

Linuo Trunnion Mount
Ball Valve

A trunnion ball valve has additional mechanical anchoring of the ball at the top and the bottom, suitable for larger and higher pressure valves (from Wikipedia). The alternative ball valve design is a  "floating" ball valve, where the valve ball is not anchored to the valve body, but rather "floats" in the valve cavity and uses upstream pressure to assist in seating and sealing.

Trunnion ball valves (TMBV) are always more expensive because of their construction and additional seating mechanics. In some situations the size and pressure class dictate use of a TMBV - usually larger size valves and higher pressure classes tend to be TMBV. 

TMBV’s are used in more extreme conditions. An example is emergency shutdown valves (ESDV) where the trunnion design combined with metal seats is typically specified. Other extreme duty examples of where TMBV’s are specified are high temperature processes an/or abrasive services. Also, TMBV's are a better choice where fire safe design is an issue, as the TMBV seat is always spring loaded.

Trunnion mounted ball valves tend to give more consistent performance, higher reliability and longer service. They often have a cavity relieving feature, which eliminates the concern about cavity pressure build-up. TMBV torques are lower and more consistent over a range of pressure change (floating ball valves increase in torque with higher pressures).

When "Double Block & Bleed" is required, the only choice are trunnion mounted valves because they are upstream sealing. Double block and bleed is a very important feature in pipeline maintenance. Additionally, in-process cleaning, seat testing and cavity cleaning are possible only in a TMBV.

Other consideration for TMBV designs are API 6D (specification for pipeline valves); pressures classifications (150 / 300 / 600 / 900 / 1500 / 2500); valve size; body materials (carbon steel A105, 316 stainless steel, chrome moly, other); blow-out proof shafts and fire safety.

What is a Segment Control Valve?

Internal view of closed
segment control valve

The most common final control element in the process industry is a control valve. The control valve influences flowing fluids such as steam, gas, water or chemicals to compensate for load changes and help regulate process variables to a desired set point. Doing this within the desired operating range ensures the quality of the product.

Close up of segment shape

Sensors and transmitters collect process information to reduce the effect of load disturbances and their relationship to a desired set point. Controllers then process this information and adjust the control valve to move the variable back to set point. A control valve is the component that implements the adjusts the process to achieve set point.

Control valves are typically an assembly of valve, internal trim, a pneumatic or electric actuator (that provides power to operate the valve) and additional accessories such as positioners, transducers, regulators or limit switches.

Cutaway view of open
segment control valve

A Segment control valve is a "quarter-turn" valve with a "sliced" or "segmented" ball. The shape of the segment offers linear control, a sweeping or cutting action when closing (making it a good choice for surries or fibers) and a tight shutoff.  Segment valves are sometimes mistakenly referred to as a "V-Port valve" or "Characterized valve", which actually refer to ball valves with modified or cutaway balls.

To better understand how segment control valves work, see this video: