Author: Bruce Zheng
Quick Answer: What Does a Plug Valve Diagram Show?
A plug valve diagram shows how the main internal and external parts of a plug valve are arranged. In most technical diagrams, buyers and engineers can identify the valve body, plug, plug port, stem, sleeve or liner, seat or sealing surface, packing area, and operator. A plug valve cross-section goes deeper by showing how the plug, port, sealing area, and flow path are positioned inside the valve body.
This article explains how to read a plug valve diagram and cross-section, how to identify the core parts, how to understand the flow path and open / closed positions, and which drawing details should be checked before RFQ or specification review.
For RFQ and drawing review, a plug valve diagram is useful because it helps the reader understand the structure before checking the datasheet, valve tag, valve list, manufacturer drawing, or project specification. However, a general article diagram should not be treated as a certified drawing, final BOM, spare parts list, or installation document.
Plug valve cross-section showing the body, plug, plug port, stem, sleeve / liner, seat, packing and flow path.
A plug valve diagram is especially useful when a buyer needs to understand:
- where the plug and plug port are located;
- how the flow path is created through the plug port;
- where the sleeve, liner, seat, or sealing surface may appear;
- where the stem packing area is located;
- how the operator connects to the stem and plug;
- which diagram details still require datasheet, drawing, or RFQ confirmation.
Different designs, such as 2-way, 3-way, sleeved, lined, lubricated, eccentric, manual, geared, or actuated plug valves, may show different details in their diagrams. These design-specific differences are discussed later in this guide.
The diagram gives a technical reading path. The final project decision still depends on the approved manufacturer drawing, datasheet, service conditions, pressure rating, material requirements, and applicable project documents.
Plug Valve Diagram vs Cross-Section vs P&ID Symbol
A plug valve diagram can mean different things depending on the context. Some diagrams show the external valve shape. Some show a cutaway or cross-section. Some are simplified symbols used in P&ID drawings. For RFQ review, these drawing types should not be treated as the same.
| Drawing Type | What It Shows | What It Does Not Show | Best Use in Review |
|---|---|---|---|
| Plug valve diagram | General structure, body shape, plug position, stem, operator, and main component relationship | Full internal detail, certified dimensions, final material list | Early technical understanding before checking the certified drawing and datasheet |
| Plug valve cross-section | Internal plug, port, body cavity, sleeve / liner, seat area, stem and packing relationship | Complete BOM, repair steps, exact project dimensions or certified material data | Understanding internal flow path, sealing areas and construction logic before RFQ confirmation |
| Plug valve parts diagram | Main visible parts or assembly groups | Full spare parts list, item quantities, repair kit data or replacement procedure | Identifying major components, but not replacing the manufacturer BOM |
| P&ID symbol | Valve type identification in a process drawing | Internal construction, sealing design, operator detail, dimensions or material | Connecting the valve symbol to the tag, line number, valve list, datasheet and specification |
| Certified manufacturer drawing | Project-specific design, dimensions, interfaces, drawing status and revision | General article-level explanation | Final engineering review, procurement confirmation and document control |
A P&ID symbol may tell the project team that the line includes a plug valve, but it does not show the internal construction. A plug valve cross-section can show internal structure, but it still may not include the final project-specific material, dimensions, end connection, operator, or testing requirements.
For symbol-level checking, an external P&ID symbol reference can support the difference between a process drawing symbol and a construction diagram.
If a general article diagram is treated as a certified project drawing, the buyer may miss differences in structure, dimensions, material, sealing design, or operator specification. For this reason, a plug valve diagram should be used as a technical understanding tool. It should be checked against the datasheet, valve list, RFQ document, and approved manufacturer drawing before any final specification decision.
How to Read a Plug Valve Cross-Section
A plug valve cross-section is a cutaway view that helps the reader understand what happens inside the valve body. Instead of only showing the external outline, the cross-section reveals how the plug, port, sealing area, stem and body are arranged.
A practical way to read a plug valve cross-section is to move from the pressure boundary to the plug and port, then to the stem, sealing interface, packing area and RFQ confirmation points. This turns a static diagram into a step-by-step engineering review path.
Not every plug valve design has the same internal detail. A lubricated plug valve, sleeved plug valve, lined plug valve, eccentric plug valve, and multi-port plug valve may show different features in the drawing. The following reading sequence is suitable for a typical technical review.
Follow the Pressure Boundary First
Start with the valve body. The body is the main pressure boundary and usually forms the external housing around the plug and flow passage. In a cross-section, the body helps the reader understand:
- where the inlet and outlet are located;
- how the valve connects to the pipeline;
- where the plug sits inside the body cavity;
- whether the valve appears to be 2-way, 3-way, flanged, threaded, welded, or another connection type;
- where pressure-containing parts may need material and rating confirmation.
The body shape alone does not confirm the final pressure class, wall thickness, end connection standard, or material grade. These details should be validated against the datasheet, approved drawing revision and project pressure requirements.
If the pressure boundary is judged only from the visual shape of the diagram, the RFQ may miss a mismatch in pressure rating, body material, end connection, or piping interface. The diagram shows the structural relationship; the datasheet and approved drawing confirm the rating.
Locate the Plug, Port and Stem
The plug is the rotating closure element inside the valve. The plug port is the opening through the plug. When the port aligns with the inlet and outlet, the valve allows flow through the passage. When the plug turns away from the flow path, the solid part of the plug blocks the passage.
The stem connects the plug to the handle, gearbox, actuator, or other operator. In a diagram, the stem helps the reviewer understand how torque is transferred from the operator to the plug.
A good plug valve cross-section should make the relationship between the body, plug, plug port and stem easy to identify. If the port shape, bore type, or plug geometry is important for the service, it should be checked against the manufacturer drawing and the valve datasheet.
Misreading the plug or port can lead to a wrong assumption about the flow path, bore type, port configuration, or torque requirement. The drawing should start the review, not finish it.
Check the Sealing and Packing Areas
After identifying the plug and port, check the sealing areas. Depending on the design, the diagram may show a sleeve, liner, seat, sealing surface, packing gland, or sealant-related passage.
These areas matter because they influence shutoff, torque, media compatibility and external sealing. For example, a sleeved or lined design may show a sleeve or liner around the plug area. A lubricated design may show sealant-related details. An eccentric plug valve may show different plug movement and sealing geometry.
The cross-section helps locate these areas, but the final selection should be checked against the datasheet, service conditions, media, pressure, temperature, material requirements and leakage requirements.
If the sealing interface is misidentified, the RFQ may specify the wrong sleeve, liner, seat, packing material or leakage expectation. For services involving corrosive media, slurry, gas, frequent operation or higher temperature, the sealing area should be reviewed carefully rather than treated as a simple label in the drawing.
Main Parts Shown in a Plug Valve Diagram
A plug valve parts diagram should help the reader identify the main component groups, not replace a full BOM or spare parts list. For RFQ review, the most useful approach is to understand what each visible part means, what can be learned from the diagram, and what still needs confirmation.
| Part Shown in the Diagram | What It Means | Why It Matters for RFQ |
|---|---|---|
| Body | Main pressure-containing housing | The diagram can show the pressure boundary and connection layout, but material, pressure class and approved interface details must be confirmed in the datasheet and drawing revision |
| Plug | Rotating closure element inside the body | Plug design affects shutoff, flow passage and torque; an unsuitable plug design can lead to poor shutoff or an incorrect flow path for the service |
| Plug Port | Opening through the plug | Helps identify flow path, full / reduced bore and port configuration, but it does not replace flow calculation or certified port data |
| Stem | Shaft connecting operator to plug | Shows the torque path from operator to plug and helps locate the packing area, but stem sizing and torque limits require technical confirmation |
| Bonnet / Cover | Upper body or closure area depending on design | May affect pressure boundary interpretation, maintenance access and drawing review, but should not be treated as a complete construction standard |
| Sleeve / Liner | Sealing or lining interface in some plug valve designs | Material or design mismatch can cause high torque, wear, media incompatibility or leakage past the plug |
| Seat / Sealing Surface | Area where shutoff is formed between plug and body / sleeve / liner | Must be reviewed against leakage requirement, shutoff expectation and service conditions instead of judged only from a simplified diagram |
| Packing / Gland | Stem sealing area | Important for external sealing, operating environment and emission concern; packing details should be checked in the final specification |
| Operator | Handle, gearbox, pneumatic actuator, electric actuator or other drive | The diagram can show operator type, but torque, actuator sizing, fail position and control requirement need separate confirmation |
Pressure Boundary Parts
The pressure boundary usually includes the body and related cover or bonnet areas. These parts are important because they must match the project pressure rating, material requirement and end connection.
A general diagram may show the body shape, but it does not confirm the final pressure class or material standard. For procurement, the body material, rating and drawing revision should be checked in the datasheet, approved drawing and project specification.
Flow-Control Parts
The plug and plug port form the main flow-control area. The plug rotates inside the body. The port is the opening that creates the flow passage when it aligns with the pipeline.
For RFQ review, the plug and port help confirm whether the valve is intended for a simple 2-way flow path, a multi-port flow path, full bore, reduced bore, or another port configuration. These visual details should trigger a specification check instead of replacing one.
Sealing and Operating Parts
The sealing system may include the sleeve, liner, seat, sealing surface, packing, gland and related details. The operating system may include a manual handle, gearbox, pneumatic actuator, electric actuator or other operator.
These details are not only mechanical labels. They affect service compatibility, torque, shutoff, automation and long-term operation. That is why the diagram should be reviewed together with the service data, datasheet and approved specification.
Sleeve, Liner, Seat and Packing Areas in the Diagram
The sealing and packing areas are among the most important details in a plug valve cross-section because they affect shutoff, operating torque, media compatibility and external sealing. A basic diagram may only show the plug and body, while a more detailed plug valve cross-section may show the sleeve, liner, seat, sealing surface, stem packing and gland area.
Sleeve or Liner Area
In some plug valve designs, a sleeve or liner may surround the plug or protect wetted surfaces. The sleeve or liner can help reduce friction, improve sealing behavior, or provide compatibility with certain media, depending on the valve design and material.
For RFQ review, the reviewer should confirm:
- whether the valve is sleeved, lined, lubricated, eccentric or another design;
- the sleeve or liner material;
- whether the liner is suitable for the medium and temperature;
- whether the drawing matches the requested valve construction.
A diagram may show the general location of the sleeve or liner, but it does not confirm the final material unless the drawing or datasheet specifies it. The sleeve or liner information should be matched with the medium, temperature, pressure and service condition before the specification is accepted.
When a cross-section shows a sleeve around the plug, compare the drawing with the sleeved plug valve structure and then confirm sleeve material in the datasheet.
Seat and Sealing Surface
The seat or sealing surface is where shutoff is formed. In a plug valve, the sealing relationship may be between the plug and body, plug and sleeve, plug and liner, or another design-specific sealing area.
This is why the phrase “plug valve diagram” should not be understood as only a simple external drawing. For buyers, the sealing area is often one of the most important parts of the cross-section because it affects leakage performance, torque and suitability for the service.
The seat or sealing surface should be checked against the required shutoff expectation, leakage requirement and service conditions. A simplified diagram can show where the sealing area is located, but it cannot prove final sealing performance by itself.
Stem Packing and Gland Area
The stem passes from the operator into the valve body and transmits motion to the plug. Around the stem, the packing and gland area helps control external leakage.
A diagram may show the approximate location of the stem packing area. For more demanding service, the packing material, gland design, emission requirement and operating condition should be confirmed with the manufacturer.
The diagram can help locate the packing area. It should not be used as a replacement for the final packing specification, especially when external sealing, emission control, frequent operation or special service conditions are important.
How the Plug Port Shows the Flow Path
The plug port is the opening through the plug. It is one of the most important features in a plug valve flow path diagram. This section explains how to identify the flow path from the diagram or cross-section. It does not confirm Cv, pressure drop, exact internal dimensions, installation direction, or final sizing.
Port Alignment and Flow Passage
In a typical 2-way plug valve diagram, the valve is open when the plug port aligns with the inlet and outlet. Fluid can pass through the opening in the plug. When the plug rotates so that the port no longer aligns with the pipeline, the solid part of the plug blocks the flow path.
This is the basic reason why plug valve diagrams often show two positions:
- open position: plug port aligned with the pipeline;
- closed position: solid plug blocks the passage.
The actual plug shape, port geometry and sealing design may differ depending on the valve type.
Full Bore, Reduced Bore and Port Shape
Some diagrams may show whether the plug port is close to the pipeline bore or smaller than the pipeline bore. A larger port may suggest a full-bore design, while a smaller passage may suggest a reduced-bore design. However, the final bore classification should be confirmed with the datasheet or manufacturer drawing.
Common port or passage details that may appear in drawings include:
| Diagram Detail | What It Means in the Diagram | What to Confirm |
|---|---|---|
| Straight-through port | Basic 2-way flow path | Bore type, end connection, pressure rating and approved drawing data |
| Reduced opening | Smaller internal passage | Flow requirement, pressure loss concern and project specification |
| Round or rectangular port | Port geometry shown in the plug | Manufacturer design, service suitability and certified port information |
| Multi-port passage | More than two flow connections | Required flow switching logic, port arrangement and valve tag function |
| Lined or sleeved passage | Wetted surface or sealing interface shown | Lining / sleeve material, media compatibility and temperature limit |
This table should be used for drawing interpretation only. A diagram may suggest bore type or port geometry, but exact internal dimensions, Cv, pressure drop data and sizing information must come from project data and manufacturer confirmation.
For a general engineering reference on plug valve port shapes and sleeve concepts, see this plug valve technical reference before using the diagram for RFQ interpretation.
Flow Path Is Not the Same as Installation Flow Direction
A plug valve flow path diagram helps explain how the flow passage is created inside the valve. It is not the same as an installation flow direction guide.
A diagram may show an inlet and outlet for explanation, but the actual installation direction, preferred flow direction, body arrow, pressure side, and orientation requirements depend on the valve design, service condition and manufacturer instructions.
For RFQ review, the buyer should confirm whether the valve is bidirectional, has a preferred flow direction, or requires a specific orientation for the application. Confusing the diagram flow path with installation direction can create the wrong project review assumption, so body marking, IOM instructions and approved drawing details should be checked separately.
For broader routing context beyond a single diagram, review plug valve flow path design after confirming the port arrangement in the cross-section.
Open and Closed Positions in a Plug Valve Diagram
A plug valve diagram may show open and closed positions to help the reader understand how the port controls the flow path. This section explains how to read that visual information without turning the article into a complete working principle guide.
Open Position
In the open position, the plug port is aligned with the inlet and outlet. The passage through the plug forms a path for fluid to move through the valve.
In a simple diagram, the open position may be shown with:
- a port aligned with the pipeline;
- a flow arrow passing through the plug;
- a plug position that creates a visible passage between inlet and outlet.
This view helps the reviewer understand the flow path, but it does not confirm pressure drop, flow coefficient, or final sizing.
Closed Position
In the closed position, the plug rotates so the port is no longer aligned with the pipeline. The solid part of the plug blocks the passage.
A closed-position diagram may show:
- the port turned away from the flow path;
- the solid plug surface facing the inlet and outlet;
- no continuous flow passage through the plug.
This is a simplified drawing method. Actual shutoff depends on plug geometry, sealing surface, sleeve or liner condition, differential pressure, torque and design quality.
Operator and Stem Movement
The operator moves the stem, and the stem rotates the plug. The operator may be a manual handle, gearbox, pneumatic actuator, electric actuator or another drive type.
In a diagram, the operator is useful because it shows how the plug is controlled. However, the diagram alone does not confirm the required torque, actuator size, control signal or automation package. These details should be reviewed in the actuator specification and valve datasheet.
When the drawing shows a handle, gearbox or actuator, compare that operator arrangement with plug valve operation types before confirming torque and automation requirements.
This article focuses on reading open and closed positions from the diagram. A complete working explanation, including quarter-turn motion, torque transfer and sealing behavior, should be handled by a dedicated plug valve working-principle guide.
For a broader explanation of quarter-turn motion, torque transfer and shutoff behavior, see our technical guide on how a plug valve works.
This short animation can help readers visualize how the plug rotates between open and closed positions. Use it as a working-position reference only; final specification should still be checked against the plug valve datasheet and manufacturer drawing.
Why Different Plug Valve Designs May Have Different Diagrams
Not every plug valve diagram looks the same. Different plug valve designs may show different internal passages, sealing areas, operator structures and port configurations. A general article diagram is useful for understanding the concept, but design-specific drawings should be checked before RFQ confirmation.
| Design | What May Look Different in the Diagram | What to Confirm |
|---|---|---|
| 2-Way Plug Valve | One inlet and one outlet flow path | Port alignment, bore type, end connection and drawing revision |
| 3-Way / Multi-Port Plug Valve | Multiple ports and different flow routes | Port configuration, switching logic, valve tag function and required flow path |
| Lubricated Plug Valve | Sealant grooves or sealant-related areas may appear | Sealant system, media compatibility, service requirement and maintenance implication |
| Sleeved Plug Valve | Sleeve may surround the plug sealing area | Sleeve material, sealing design, torque implication and service suitability |
| Lined Plug Valve | Lining may appear on wetted surfaces | Lining material, corrosion service, temperature limit and chemical compatibility |
| Eccentric Plug Valve | Plug position, motion path or sealing geometry may differ | Design-specific drawing, sealing geometry and service conditions |
| Actuated Plug Valve | Operator area changes above the stem | Torque requirement, control signal, fail position and actuator type |
Two-Way and Three-Way Plug Valve Diagrams
A 2-way plug valve diagram usually shows one inlet and one outlet. A 3-way or multi-port plug valve diagram may show more than two connections and different flow routes.
For this article, the key point is not to explain all plug valve types. The key point is that the diagram must show the required port arrangement clearly enough for the buyer to check the tag, valve list and process function before RFQ.
Lubricated, Sleeved and Lined Plug Valve Diagrams
A lubricated plug valve diagram may show sealant-related features. A sleeved plug valve diagram may show the sleeve around the plug. A lined plug valve diagram may show lining on wetted surfaces.
These details should stay within the drawing review scope. For RFQ, the buyer should confirm the sealing or lining design, material compatibility, temperature limit and service condition in the datasheet or manufacturer drawing.
Eccentric and Actuated Plug Valve Diagrams
An eccentric plug valve may show a different plug position, motion path or sealing geometry compared with a centered plug design. The exact detail depends on the manufacturer and design.
If the diagram shows an off-center plug position or different sealing geometry, review the eccentric plug valve page before treating it as a standard centered-plug layout.
An actuated plug valve diagram may show a pneumatic actuator, electric actuator, hydraulic actuator, gearbox or accessories above the stem. The operator arrangement should be checked against torque demand, control requirement, fail position and automation specification.
What Buyers Should Confirm Before RFQ or Drawing Review
A plug valve diagram is useful only when it leads to better specification review. Before sending an RFQ or approving a drawing, buyers should confirm the diagram information against the datasheet, valve tag, valve list, service data and manufacturer drawing.
| RFQ Check Item | Why It Matters | Source to Confirm |
|---|---|---|
| Valve type | Confirms the plug valve design family and prevents mixing different construction types | RFQ, datasheet, valve list |
| Size and pressure class | Controls pressure boundary, piping interface and project rating requirement | Datasheet, manufacturer drawing, project specification |
| End connection | Affects piping connection, installation interface and matching with line specification | Drawing, valve list, piping specification |
| Body material | Affects pressure boundary, corrosion resistance and media compatibility | Datasheet, material certificate requirement |
| Plug material / coating | Affects sealing, corrosion resistance, wear behavior and service life | Datasheet, manufacturer drawing |
| Sleeve / liner / seat material | Affects sealing suitability, torque behavior, media compatibility and leakage performance | Datasheet, service condition, manufacturer confirmation |
| Port configuration | Affects flow path, switching logic and whether the valve matches the intended process function | Cross-section, manufacturer drawing, project requirement |
| Full bore / reduced bore | Affects internal passage, flow expectation and specification review | Datasheet, manufacturer data |
| Operator / actuator | Must match torque demand, operating frequency, control requirement and automation package | Datasheet, actuator specification |
| Service medium | Affects material, lining, sealing design and corrosion / wear risk | Process data, RFQ |
| Temperature and pressure | Affects rating, sealing design and material suitability | Process condition, datasheet |
| Valve tag and revision | Prevents using outdated drawing information or mismatched project documents | Valve list, document control system |
A plug valve cross-section can help check whether the flow path, port configuration and sealing layout match the RFQ intent. The final specification still requires approved drawing, datasheet and project document confirmation.
Drawing and Datasheet Checks
The diagram may help the buyer understand the valve structure, but the datasheet confirms the project requirements. The reviewer should check whether the drawing and datasheet use the same valve type, size, pressure class, end connection, material and operator.
If the diagram shows a sleeve, liner, special port or actuator, these details should also appear clearly in the technical documents.
Valve Specification Checks
A plug valve specification should not be confirmed only by looking at a picture. The buyer should check the valve design, plug type, port configuration, sealing design, pressure rating, material and operator.
For example, if the service requires a lined plug valve, the diagram should not be treated as enough evidence unless the lining material and service compatibility are confirmed in the datasheet or manufacturer drawing. Ask the supplier to state the lining material, temperature limit and media compatibility in the technical documents, then cross-check those details against the process temperature, pressure and chemical list.
For lined construction, use the lined plug valve page as a product-specific reference, then verify lining material, temperature limit and media compatibility in the project documents.
Service Condition and Operator Checks
The same diagram may not be suitable for every medium or operating condition. Slurry, corrosive media, gas, high temperature, frequent operation, automation and differential pressure can all affect valve selection.
The operator also needs review. A manual handle may be suitable for some smaller or lower-torque valves, while gearbox or actuation may be required for larger sizes, higher torque or remote control. The diagram helps identify the operator type, but actuator sizing and torque confirmation require technical calculation and manufacturer confirmation.
For RFQ support, provide the medium, pressure, temperature, valve size, pressure class, end connection, material requirement, sealing design, operator requirement, port configuration, valve tag and any available drawing or datasheet.
FAQ About Plug Valve Diagrams
What does a plug valve diagram show?
A plug valve diagram usually shows the valve body, plug, plug port, stem, sealing area, packing area and operator. A more detailed plug valve cross-section may also show the sleeve, liner, seat, flow path and internal sealing relationship.
What is the difference between a plug valve diagram and a cross-section?
A plug valve diagram may show the general structure or external arrangement. A plug valve cross-section is a cutaway view that shows internal parts such as the plug, port, sleeve or liner, seat and flow path.
What parts are shown in a plug valve diagram?
Common parts shown in a plug valve diagram include the body, plug, plug port, stem, bonnet or cover, sleeve or liner, seat or sealing surface, packing gland and operator. An article diagram usually shows main components only. It does not replace a full BOM, small fastener list, spare parts list or approved manufacturer drawing.
How does the plug port show the flow path?
The plug port is the opening through the plug. When the port aligns with the inlet and outlet, it creates a flow path. When the plug turns away from the line, the solid plug blocks the passage.
How can you tell whether a plug valve is open or closed in a diagram?
A plug valve is usually shown open when the plug port aligns with the pipeline. It is shown closed when the solid part of the plug blocks the flow path. This is a diagram-reading method, not a full operating, maintenance or installation instruction.
Is a plug valve diagram the same as a P&ID symbol?
No. A P&ID symbol identifies the plug valve in a process drawing, but it does not show full internal construction, sealing design or operator detail. A plug valve diagram or cross-section is used to understand structure, parts and flow path.
How is an eccentric plug valve diagram different?
An eccentric plug valve diagram may show an off-center plug position, different motion path or different sealing geometry compared with a centered plug valve design. The exact details depend on the manufacturer, so eccentric plug valve specifications should be checked with the design-specific drawing and datasheet.
Can a plug valve diagram show full bore or reduced bore?
Yes, some diagrams can help the reader understand whether the port appears full bore or reduced bore. However, the final bore type, internal dimensions and flow requirement should be confirmed with the datasheet or manufacturer drawing.
Can a plug valve cross-section confirm the sleeve or liner material?
A cross-section can show where the sleeve or liner is located, but it usually cannot confirm the final sleeve or liner material unless the drawing or datasheet states it clearly. For RFQ review, the material should be checked against the media, temperature and service condition.
Can I use an article diagram as a certified drawing or BOM?
No. An article diagram is only for technical understanding. It should not replace a certified manufacturer drawing, approved datasheet, BOM, material list, IOM, purchase approval document, or project-controlled drawing.
Conclusion
A plug valve diagram helps buyers and engineers understand the internal structure of a plug valve before RFQ or drawing review. A useful diagram can show the body, plug, plug port, stem, sleeve or liner, seat, packing area, operator, flow path and open / closed positions. A plug valve cross-section adds more value by showing the relationship between the internal flow-control and sealing areas.
For engineering and procurement decisions, the diagram should be used together with the datasheet, valve tag, valve list, service conditions and manufacturer drawing. It should not be treated as a final certified drawing, BOM, repair manual or installation instruction.
Before finalizing an RFQ, use the checklist above to compare the plug valve diagram, cross-section and datasheet against the actual service requirements. If there are questions about structure, sealing design, port configuration, lining material, operator type or drawing revision, provide the available drawing, datasheet, valve tag and process conditions for specification review.
If the diagram review raises broader selection questions, compare the checklist with our guide on how to choose the right type of plug valve before final RFQ confirmation.
NTGD Plug Valve can support plug valve specification review based on service medium, pressure, temperature, valve size, pressure class, end connection, material requirement, sealing design, port configuration, operator type and available project drawings. For RFQ confirmation, share the drawing, datasheet, valve tag or process condition so the plug valve structure and specification can be reviewed correctly.