Description
API 6A Manual Flat Gate Valve for Wellheads, Christmas Trees and Manifolds
SGPE supplies API 6A Manual Flat Gate Valves for pressure isolation on oil and gas wellheads, Christmas trees, surface test trees, production trees and high-pressure manifold systems.
The valve uses a parallel flat gate that moves between two pressure-energized seat assemblies. When fully open, the port through the gate aligns with the body bore and creates a straight through-conduit flow path. This full-opening structure reduces internal restriction, limits turbulence and moves the primary sealing surfaces away from the main production flow.
Nominal sizes range from 1-13/16 in. to 7-1/16 in. Standard rated working pressures include 2,000, 3,000, 5,000, 10,000 and 15,000 psi. Selected valve designs can also meet 20,000 psi requirements after a model-specific engineering review.
Customers can choose rising or non-rising stems, forged or cast pressure-containing bodies and flanged, studded, threaded or project-specific end connections. Metal-to-metal gate and seat sealing supports high-pressure isolation, while hardfacing, stainless-steel trim and corrosion-resistant alloys address abrasive, corrosive and H₂S-containing well fluids.
Product Short Description
SGPE API 6A Manual Flat Gate Valves provide full-bore pressure isolation for oil and gas wellheads, Christmas trees, surface test trees, flowheads, choke manifolds, kill manifolds and production manifolds.
Also known as FC gate valves, manual slab gate valves or manual wellhead gate valves, they use a parallel gate and pressure-energized seat assemblies to form a straight through-conduit flow path when fully open. This arrangement reduces internal restriction, limits turbulence and keeps the primary metal-to-metal sealing surfaces away from the main production flow.
Customers can select rising-stem or non-rising-stem configurations, forged or cast bodies and flanged, studded or threaded end connections. Nominal sizes range from 1-13/16 in. to 7-1/16 in., with standard working pressures from 2,000 to 15,000 psi and selected designs up to 20,000 psi after engineering review. Sour-service trim, hardfacing and CRA options support abrasive, corrosive and H₂S-containing fluids in production, well testing, flowback, workover and well-intervention applications.
API 6A Manual Flat Gate Valve Specifications
| Parameter | Available Configuration |
|---|---|
| Product Name | API 6A Manual Flat Gate Valve |
| Related Product Terms | Manual slab gate valve, FC gate valve, manual wellhead gate valve |
| Valve Design | Parallel flat gate / through-conduit gate valve |
| Nominal Size | 1-13/16 in. to 7-1/16 in. |
| Standard Working Pressure | 2,000, 3,000, 5,000, 10,000 and 15,000 psi |
| Special Pressure Option | Selected 20,000 psi designs after engineering review |
| Bore Design | Full bore / full opening / through conduit |
| Stem Design | Rising stem or non-rising stem |
| Operation | Manual handwheel |
| Body Construction | Forged or cast |
| End Connection | Flanged, studded, threaded or project-specific |
| Primary Seal | Metal-to-metal gate and seat seal |
| Seat Design | Pressure-energized with controlled preload |
| Body-to-Bonnet Seal | Metal or qualified project-specific pressure seal |
| Stem Backseat | Metal-to-metal |
| Material Class | AA, BB, CC, DD, EE, FF or HH, subject to design |
| Temperature Class | Project-specific API 6A temperature class |
| Product Specification Level | PSL 1 through PSL 4, subject to product design |
| Performance Requirement | PR1 or PR2 |
| Sour Service | NACE MR0175 / ISO 15156 materials when specified |
| Applicable Standards | API Spec 6A / ISO 10423 as stated in the purchase order |
The final valve configuration depends on the nominal size, minimum bore, pressure rating, end connections, fluid composition, temperature class, material class, PSL, PR and inspection scope.
Face-to-face length, handwheel diameter, bolting, operating torque and valve weight vary by model. SGPE confirms these details on the approved technical datasheet and general arrangement drawing before production.
API 6A Manual Gate Valve Pressure Ratings
| Rated Working Pressure | Approximate Metric Pressure |
| 2,000 psi | 13.8 MPa |
| 3,000 psi | 20.7 MPa |
| 5,000 psi | 34.5 MPa |
| 10,000 psi | 69.0 MPa |
| 15,000 psi | 103.4 MPa |
| 20,000 psi | 137.9 MPa |
The valve rating must equal or exceed the maximum allowable working pressure of the connected wellhead, Christmas tree or manifold.
Production and acceptance tests follow the applicable product specification, approved test procedure and purchase-order requirements.
How a Full-Bore Through-Conduit Gate Valve Works
Unlike a conventional wedge gate valve, an API 6A flat gate valve uses a parallel-sided gate with a machined flow port.
Turning the handwheel moves the stem and gate between the open and closed positions. Once the valve opens fully, the gate port lines up with the body bore. Oil, gas, condensate, produced water or well-service fluid can then pass through a continuous flow path.
The straight bore lowers pressure loss and reduces turbulence around the sealing area. It also leaves fewer restricted spaces where sand, scale or other solids can collect.
In the fully open position, the gate sealing surfaces move away from the main flow stream. This limits their direct exposure during production, flowback and well testing.
The full-bore structure may also support compatible wireline, slickline and pressure-control tools. Tool passage still depends on the actual minimum bore and the outside diameter of the intervention equipment. Projects requiring through-bore access should state the maximum tool diameter in the inquiry.
This valve provides isolation rather than flow control. Operators should keep it fully open or fully closed and use a choke valve or control valve for continuous pressure reduction or flow regulation.
API 6A Manual Flat Gate Valve Design Features
| Design Feature | Construction | Practical Benefit |
| Parallel Flat Gate | Gate with a machined through port | Creates a straight flow path when fully open |
| Pressure-Energized Seats | Two seats positioned around the gate | Uses line pressure to support sealing |
| Controlled Seat Preload | Wave springs or equivalent components | Maintains seat contact at lower pressure |
| Metal-to-Metal Seal | Metal contact between gate and seats | Supports high-pressure and abrasive service |
| Full-Opening Bore | Gate port aligns with the body bore | Reduces internal flow restriction |
| Manual Handwheel | Mechanical handwheel and stem drive | Allows local operation without external power |
| Thrust Bearings | Bearings within the operator assembly | Reduce friction and handwheel effort |
| Metal Backseat | Metal contact behind the stem packing area | Supports controlled stem-seal isolation |
| Grease Injection | Lubrication point on the bonnet or operator | Protects the stem and moving components |
| Sealant Injection | Optional emergency sealant access | Supports temporary leakage management |
| Replaceable Trim | Serviceable gate, seats, stem and seals | Simplifies overhaul and spare-parts planning |
Metal-to-Metal Gate and Seat Sealing
The parallel gate seals against two seat assemblies through metal-to-metal contact. This arrangement supports repeated pressure cycles, changing temperatures and extended shut-in periods.
The sealing system also suits well fluids that carry produced sand or other abrasive solids. Actual trim life depends on fluid velocity, particle concentration, particle size and operating practice.
Depending on the selected design, the seats may seal against the body through a metal pressure seal or another qualified arrangement.
Gate and seat options can include tungsten carbide, Stellite or equivalent hardfacing, stainless steel, nickel alloys, corrosion-resistant alloy cladding and Inconel 625 overlay.
Before selecting the trim, SGPE reviews the working pressure, temperature, H₂S partial pressure, CO₂ content, chloride concentration, produced-water chemistry and expected sand loading.
Pressure-Energized Seats and Bi-Directional Isolation
Line pressure helps energize each seat against the gate. At lower pressure, wave springs or equivalent preload components maintain contact between the sealing surfaces.
This sealing principle supports well shut-in, production switching, flowback, surface well testing, manifold maintenance and pressure testing.
Selected API 6A manual slab gate valves can isolate pressure from either side. Bi-directional sealing becomes important when pressure may come from the wellbore, production flowline, test manifold or pressure-test equipment.
The inquiry should state whether the valve must isolate pressure from the well side, downstream side or both directions. The approved test procedure can then verify the required sealing performance.
Manual Operation and Operating Torque
The stem, thrust bearings, gate and seat assemblies work together to reduce operating resistance. The handwheel allows local operation without hydraulic, pneumatic or electric power.
Operating torque varies with valve size, minimum bore, pressure rating, differential pressure, stem arrangement, seat design and lubrication condition. Deposits, produced solids and trim wear may increase the required effort over time.
When a project requires torque verification, SGPE can provide calculated or tested data for the selected model.
Operators should not use hammer blows, impact tools or unauthorized handwheel extensions. Excessive force can damage the stem, thrust bearings, gate or handwheel assembly.
Rising-Stem vs. Non-Rising-Stem Gate Valves
| Selection Factor | Rising-Stem Design | Non-Rising-Stem Design |
| Stem Movement | Stem rises as the valve opens | Stem movement remains mainly inside the bonnet |
| Position Indication | Direct visual indication | May use a separate position indicator |
| Installation Height | Requires more vertical clearance | Provides a compact overall height |
| Stem Exposure | Exposes more stem surface | Protects more of the stem |
| Common Locations | Master, wing and swab valves | Compact trees, manifolds and offshore modules |
| Main Advantage | Clear local position confirmation | Space-saving installation |
A rising-stem gate valve gives the operator a direct visual indication of valve movement. It commonly serves as a master valve, production wing valve, kill wing valve or swab valve.
A non-rising-stem valve keeps most stem movement inside the bonnet. Its compact structure suits restricted wellhead layouts, manifold skids, mobile test packages and offshore modules. It also protects more of the stem from dust, sand and salt spray.
Available installation space and the required method of position indication usually determine the stem design.
FC-Type Manual Slab Gate Valve
The FC gate valve is a widely used single-gate, full-bore valve for API 6A wellhead and Christmas tree service.
A typical FC-type manual gate valve includes a pressure-containing body, one parallel gate, two pressure-energized seats, a bonnet, stem, thrust bearings, handwheel, stem packing, backseat and lubrication fittings.
Connection arrangements can include flanged-by-flanged, flanged-by-threaded, studded-end and threaded-end designs. Customers can also choose rising or non-rising stems, forged or cast bodies and trim for standard, abrasive or sour service.
Different manufacturers may use different bores, face-to-face dimensions, seat profiles, stem arrangements and bonnet structures. The term “FC gate valve” therefore does not confirm interchangeability by itself.
For replacement work, provide the original manufacturer, model, nameplate, minimum bore, face-to-face length, end connections and available drawings. These details allow SGPE to compare the proposed replacement with the existing wellhead or Christmas tree interface.
API 6A Wellhead and Christmas Tree Valve Applications
| Equipment | Typical Valve Position | Isolation Function |
| Casing Head | Side or annulus outlet | Isolates casing-annulus pressure |
| Tubing Head | Side outlet or annulus access | Controls tubing-annulus access |
| Christmas Tree | Upper or lower master valve | Provides primary wellbore isolation |
| Christmas Tree | Production wing valve | Isolates the production flow path |
| Christmas Tree | Kill wing valve | Isolates the kill or injection branch |
| Christmas Tree | Swab valve | Controls vertical access above the tree |
| Surface Test Tree | Main isolation valve | Supports well testing and temporary production |
| Choke Manifold | Branch isolation valve | Selects the required choke flow path |
| Kill Manifold | Pump or line isolation valve | Isolates kill-fluid and test branches |
| Production Manifold | Well-selection valve | Directs wells to production or testing |
| Well-Test Manifold | Test-line block valve | Isolates separators and flowback equipment |
| Intervention System | Pressure-isolation valve | Supports intervention preparation |
Wellhead and Christmas Tree Isolation
On casing heads and tubing heads, a manual wellhead gate valve can isolate side outlets, annulus lines, pressure-monitoring connections, chemical-injection points and test branches.
On a Christmas tree, the same design can provide master, wing, swab or annulus isolation according to the tree layout.
Each position creates different pressure and flow conditions. The minimum bore, pressure rating, sealing direction and end connections must therefore match the complete wellhead or tree configuration.
Surface Test Tree and Flowhead Service
Surface test trees need dependable isolation during well cleanup, initial flow, pressure buildup, flowback, production testing and temporary production.
During these operations, the valve may encounter gas, condensate, produced water, sand and changing pressure conditions. The pressure class, trim and minimum bore should reflect the test program, fluid composition and intervention requirements.
Choke, Kill and Production Manifolds
Manual flat gate valves isolate branches on choke manifolds, kill manifolds, production manifolds, well-test manifolds and well-selection manifolds.
On a choke manifold, the gate valve provides isolation while the choke controls pressure and flow. On a kill manifold, it isolates pump lines, kill-fluid branches and test connections. On a production manifold, it directs a well toward production, testing or injection service.
The gate should not remain partly open for flow control because high-velocity fluid and solids can erode the sealing surfaces.
Workover and Well-Intervention Service
A full-bore wellhead gate valve can provide pressure isolation during wireline, slickline, electric-line, coiled-tubing and snubbing operations.
It can also support well re-entry, wellhead repair, Christmas tree replacement, pressure-control equipment testing and abandonment preparation.
A full-bore description alone does not confirm tool passage. The actual minimum bore must be checked against the maximum outside diameter of the intervention equipment.
Service Media and Material Selection
| Service Condition | Information to Provide | Typical Engineering Review |
| Sweet Oil or Gas | Pressure, temperature and fluid composition | Standard body and trim |
| H₂S-Containing Fluid | H₂S partial pressure, water phase and pH when available | NACE MR0175 / ISO 15156 review |
| CO₂-Containing Fluid | CO₂ content, temperature and water content | Corrosion-resistant trim or overlay |
| Produced Water | Chloride content, pH and temperature | CRA trim or corrosion review |
| Sand-Bearing Production | Sand concentration, particle size and velocity | Hardfaced gate and seats |
| Completion Brine | Brine chemistry, density and chloride level | Compatible trim and seals |
| Drilling or Kill Fluid | Fluid type, solids and additives | Abrasion and chemical compatibility review |
| Injection Water | Water chemistry, oxygen and chloride content | Corrosion-resistant material review |
| Offshore Environment | Coating and preservation requirements | Marine coating and preservation |
| Low-Temperature Service | Minimum ambient and fluid temperatures | Low-temperature materials and seals |
| High-Temperature Service | Maximum continuous and transient temperatures | High-temperature trim and seals |
Applicable media can include crude oil, natural gas, associated gas, condensate, produced water, completion brine, drilling fluid, kill fluid, workover fluid, injection water, injection gas, flowback fluid and multiphase production fluid.
The fluid name alone does not provide enough information for material selection. H₂S, CO₂, chlorides, water content, solids, temperature and pressure cycles all influence the body, trim and sealing system.
API 6A Material Classes and Trim Options
Material classes AA, BB, CC, DD, EE, FF and HH are available subject to the selected valve design and service conditions.
A material-class designation does not define every pressure-containing and pressure-controlling component. Material selection must also consider fluid composition, pressure, temperature, corrosion risk, erosion risk and project specifications.
Body and bonnet options may use carbon steel, low-alloy steel or forged alloy steel. Stainless-steel stems and project-specific internal materials support different production environments.
Trim options can include 410 stainless steel, 13Cr, 17-4PH, nickel alloys and corrosion-resistant alloy cladding. Inconel 625 overlay or another CRA can protect pressure-wetted areas in corrosive service.
For sand-bearing or abrasive fluids, tungsten carbide, Stellite or equivalent hardfacing can improve gate and seat resistance.
For H₂S-containing service, SGPE reviews the body, bonnet, stem, gate, seats, bolting and sealing components against the stated operating conditions and purchase-order requirements.
API 6A Temperature Requirements
Temperature-class availability depends on the valve design, body material, trim and sealing system.
A commonly requested example appears below:
| Example Temperature Class | Minimum Temperature | Maximum Temperature |
| LU | −46°C / −50°F | +121°C / +250°F |
Other classes may suit standard, low-temperature or elevated-temperature service.
The inquiry should include the required API temperature class, the minimum and maximum ambient temperatures and the normal and maximum fluid temperatures.
The approved temperature range applies to the complete valve assembly rather than the body material alone.
API 6A Gate Valve End Connections
| Connection Type | Typical Use | Required Information |
| API 6B Flange | Selected lower and medium pressure classes | Size, rating and ring groove |
| API 6BX Flange | High-pressure wellhead and tree equipment | Size, rating and BX ring number |
| Flanged-by-Flanged | Standard tree and manifold installation | Both flange details and face-to-face length |
| Flanged-by-Threaded | Transition between connection types | Flange and thread details |
| Studded End | Compact wellhead or manifold layout | Stud pattern, ring groove and mating interface |
| Threaded End | Selected smaller valve designs | Thread type, size, pitch and pressure rating |
| Hub or Clamp Connection | Compact or proprietary interface | Hub profile, clamp and seal details |
| OEM Replacement Connection | Existing wellhead or tree | Drawings, dimensions and photographs |
The connection must match both the pressure rating and the physical interface of the mating equipment.
For replacement valves, confirm the ring groove, minimum bore, face-to-face length, bolting arrangement and installation orientation before manufacturing begins.
Common API 6A Gate Valve Sizes and Pressure Ratings
The following combinations provide preliminary selection guidance. Actual availability depends on body design, minimum bore, end connection, material class, PSL and PR.
| Nominal Size | Common Pressure Options |
| 1-13/16 in. | 5,000, 10,000, 15,000 and selected 20,000 psi |
| 2-1/16 in. | 2,000, 3,000, 5,000, 10,000 and 15,000 psi |
| 2-9/16 in. | 2,000, 3,000, 5,000, 10,000 and 15,000 psi |
| 3-1/8 in. | 2,000, 3,000 and 5,000 psi |
| 3-1/16 in. | 10,000 and 15,000 psi |
| 4-1/16 in. | 3,000, 5,000, 10,000 and 15,000 psi |
| 5-1/8 in. | 2,000, 3,000 and 5,000 psi |
| 7-1/16 in. | 2,000, 3,000, 5,000, 10,000 and selected 15,000 psi |
SGPE confirms each size and pressure combination on the model-specific datasheet before order placement.
Need a Model-Specific Valve Datasheet?
Send the nominal size, minimum bore, working pressure and end connections. SGPE will review the requirement and provide the applicable configuration, dimensions and quotation.
Request Valve Datasheet
How to Select an API 6A Manual Flat Gate Valve
1. Confirm the Nominal Size and Minimum Bore
State the nominal valve size and the required minimum through bore. The bore should match the connected wellhead, Christmas tree, surface test tree or manifold.
For intervention service, also include the maximum tool outside diameter.
2. State the Rated Working Pressure
Specify the required rated working pressure in psi or MPa. Also confirm the maximum expected operating and test pressures.
3. Define the End Connections
Provide the flange size, flange type, ring groove, ring-gasket number and face-to-face length.
For threaded, studded, hub or clamp connections, include the complete interface details and available drawings.
4. Describe the Service Fluid
Identify the oil, gas, condensate, produced water, completion brine, drilling fluid, kill fluid or multiphase fluid.
For corrosive or sour service, include available H₂S, CO₂, chloride, water and sand data.
5. Confirm the Temperature Range
State the minimum and maximum ambient temperatures together with the normal and maximum fluid temperatures.
6. Specify Materials and Trim
Provide the required API 6A material class and any hardfacing, stainless-steel trim or CRA-overlay requirements.
7. Define PSL and PR
State the required Product Specification Level and Performance Requirement. Higher requirements may increase material traceability, NDE, hardness control, design validation and documentation.
8. Select the Stem Design
Choose a rising stem for direct visual position indication. Choose a non-rising stem where vertical clearance is limited.
9. Confirm the Sealing Direction
State whether the valve must seal from the well side, downstream side or both directions.
10. Confirm Inspection and Documentation
Identify the inspection, witness and document requirements before quotation because they can affect manufacturing time, price and delivery.
Quality Control and API 6A Gate Valve Testing
| Stage | Typical Inspection or Test | Available Record |
| Raw Material | Identification and certificate review | MTC and traceability record |
| Heat Treatment | Cycle and parameter review | Heat-treatment record |
| Hardness | Body, bonnet, stem or trim check | Hardness report |
| PMI | Alloy verification when specified | PMI report |
| Machining | Bore, flange and ring-groove inspection | Dimensional report |
| Surface NDE | MPI or LPI on specified parts | NDE report |
| Volumetric NDE | UT or RT when required | UT or RT report |
| Hardfacing or Overlay | Thickness and surface inspection | Overlay report |
| Assembly | Gate, seat, stem and operator checks | Assembly record |
| Shell Test | Pressure-boundary hydrostatic test | Shell test report |
| Seat Test | Gate and seat sealing test | Seat test report |
| Bi-Directional Test | Test from specified pressure directions | Bi-directional test record |
| Low-Pressure Test | Low-pressure seat test when required | Low-pressure test report |
| Functional Test | Opening, closing and position check | Functional test report |
| Final Inspection | Marking, coating and packing | Final inspection report |
The inspection and test plan reflects the valve design, PSL, PR and purchase specification.
PR2 requires a separate technical review because a routine production pressure test does not represent complete PR2 design validation.
SGPE can coordinate third-party inspection with SGS, Bureau Veritas, DNV, ABS, TÜV or another agreed inspection organization.
Available Technical Documentation
The project document package can include the technical datasheet, general arrangement drawing, cross-sectional drawing and bill of materials.
Material and manufacturing records may include MTCs, heat-treatment records, hardness reports, PMI results, NDE reports and dimensional inspection records.
After assembly and testing, the package can include shell and seat test reports, functional test records, coating reports, certificates of conformity and third-party inspection reports.
SGPE can also provide operation and maintenance manuals, spare-parts lists, inspection and test plans, packing lists and manufacturing record books according to the agreed document index.
Confirm the required document scope before quotation because it may affect inspection planning, delivery and cost.
Installation, Operation and Maintenance
Before installation, verify the valve size, minimum bore, pressure rating, material class, temperature class and end connections.
Inspect the flange faces and ring grooves, confirm the correct ring gasket and clean all sealing surfaces. The installation must provide enough room for handwheel operation. A rising-stem valve also needs sufficient vertical clearance.
Connected equipment should not impose excessive bending load on the valve body. Do not use the valve to pull misaligned wellhead, tree or manifold components into position.
During operation, turn the handwheel at a controlled speed and check the differential pressure before moving the gate. Do not use impact tools or unauthorized extensions. Keep the valve fully open or fully closed during normal service.
Routine maintenance should include external leakage checks, stem lubrication, grease-fitting inspection and periodic operation of standby valves. A gradual increase in operating torque may indicate deposits, poor lubrication, corrosion or trim wear.
During a planned overhaul, inspect the flange faces, ring grooves, gate, seats, packing and bearings. Before disassembly, isolate, depressurize and drain the valve and connected equipment according to the approved field procedure.
Spare Parts and OEM Replacement FC Gate Valves
SGPE can supply flat gates, seat assemblies, stems, stem packing, body and bonnet seals, wave springs, thrust bearings, handwheels, position indicators, grease fittings, sealant fittings and bonnet bolting.
Complete repair kits and internal trim packages are also available for selected models.
For an OEM replacement FC gate valve or manual wellhead valve, provide the original manufacturer, model, serial number, nominal size, minimum bore, pressure rating, material class and temperature class.
Include the end-connection details, ring-gasket number, face-to-face length and installation orientation.
Nameplate photographs, connection photographs and original drawings improve the dimensional and technical review.
Why Choose SGPE’s API 6A Manual Flat Gate Valve?
Wellhead Valve Supply
SGPE supplies manual gate valves and pressure-control equipment for drilling, completion, production, well testing, intervention and workover operations.
The range covers FC-type gate valves, manual slab gate valves, rising-stem and non-rising-stem designs, forged and cast bodies, sour-service trim and OEM replacement configurations.
Technical Review Before Quotation
Before quotation, SGPE reviews the minimum bore, pressure rating, end connections, fluid composition, H₂S and CO₂ data, temperature class, material class, PSL, PR and inspection scope.
This review helps prevent incorrect bore, connection, trim and document selections.
Project and Replacement Support
Supply can range from one emergency replacement valve to complete Christmas tree, surface test tree, choke manifold, kill manifold or production manifold valve packages.
Where remote or fail-safe operation is required, SGPE can also offer hydraulic, pneumatic and electric operators as separate configurations.
Inspection and After-Sales Service
Support can include installation review, valve identification, spare-parts selection, maintenance planning, troubleshooting and third-party inspection coordination.
Information Required for Quotation
| Required Information | Example |
| Product | API 6A Manual Flat Gate Valve |
| Nominal Size | 2-1/16 in. |
| Working Pressure | 10,000 psi / 69.0 MPa |
| Minimum Bore | According to Christmas tree bore |
| Stem Type | Rising stem |
| Body Construction | Forged |
| End Connection | API 6BX flanged ends |
| Ring Groove | BX-152 |
| Face-to-Face Length | According to existing valve |
| Material Class | EE |
| Temperature Class | LU |
| PSL | PSL 3 |
| PR | PR2 |
| Service Fluid | Oil and gas with H₂S |
| H₂S and CO₂ Data | Concentration or partial pressure |
| Chloride Content | Actual value when available |
| Trim Requirement | 410 SS with tungsten carbide |
| Sealing Direction | Bi-directional |
| Application | Christmas tree master valve |
| Quantity | 2 units |
| Documentation | MTC, NDE, pressure test and COC |
| Inspection | Third-party inspection |
| Delivery Destination | City, port and country |
For replacement work, also provide the nameplate, dimensions, connection details and clear photographs.
Frequently Asked Questions About API 6A Manual Flat Gate Valves
1. What is an API 6A manual flat gate valve?
An API 6A manual flat gate valve is a high-pressure isolation valve used on oil and gas wellheads, Christmas trees, surface test trees, production trees and manifold systems.
A handwheel moves a parallel flat gate between two seat assemblies. When the valve opens fully, the gate port aligns with the body bore and creates a straight through-conduit flow path. The full-bore structure reduces internal restriction and keeps the primary sealing surfaces away from the main production flow.
Buyers may also refer to this product as an API 6A manual gate valve, manual slab gate valve, FC gate valve, manual wellhead gate valve, full-bore gate valve or manual Christmas tree valve.
2. Is a flat gate valve the same as a slab gate valve?
In API 6A wellhead service, the terms flat gate valve and slab gate valve commonly describe a parallel-gate, through-conduit design.
Both use a flat gate that moves between two seats and creates a straight bore when fully open. Manufacturers may still use different seat geometry, stem arrangements, bonnet structures, minimum bores and face-to-face dimensions.
Similar product names do not guarantee interchangeability.
3. What is an FC gate valve?
An FC gate valve is a widely used single-gate, full-bore valve for API 6A wellheads, Christmas trees, surface test equipment and high-pressure manifolds.
A typical FC-type valve includes a pressure-containing body, one parallel gate, two pressure-energized seats, a bonnet, stem, handwheel, thrust bearings, stem packing, backseat and lubrication fittings.
Customers can select rising or non-rising stems, forged or cast bodies and flanged, studded or threaded connections according to the service conditions.
4. Where is a manual wellhead gate valve installed?
A manual wellhead gate valve can serve in several pressure-isolation positions on wellhead and production equipment.
On a Christmas tree, it may act as an upper master valve, lower master valve, production wing valve, kill wing valve, swab valve or annulus valve. It can also isolate casing-head outlets, tubing-head outlets, surface test trees, flowheads and manifold branches.
The correct configuration depends on the installation position, minimum bore, working pressure, sealing direction and end connections.
5. What sizes and working pressures are available?
Common nominal sizes range from 1-13/16 in. to 7-1/16 in.
Standard rated working pressures commonly include 2,000, 3,000, 5,000, 10,000 and 15,000 psi. Selected designs may also meet 20,000 psi requirements after engineering review.
Not every size is available in every pressure class. Minimum bore, body construction, end connections, material class, temperature class, PSL and PR all affect model availability.
6. Can an API 6A manual gate valve handle H₂S service?
Yes. SGPE can configure an API 6A manual gate valve for H₂S-containing or sour-service applications when the materials match the stated operating environment.
The review should cover the body, bonnet, stem, gate, seats, bolting, seals and any pressure-wetted overlay. H₂S partial pressure, CO₂ content, chlorides, water phase, pH, pressure and temperature all influence material selection.
When specified, applicable materials can meet NACE MR0175 / ISO 15156 requirements.
7. What is the difference between rising-stem and non-rising-stem gate valves?
A rising-stem gate valve moves the stem upward as the valve opens. This movement gives the operator a direct visual indication of valve position.
A non-rising-stem design keeps most stem movement inside the bonnet. It reduces installation height and protects more of the stem from dust, sand, moisture and offshore salt spray.
The final choice depends on available space, maintenance access and position-indication requirements.
8. Can a manual flat gate valve be used to throttle well flow?
No. A manual flat gate valve provides isolation and should normally remain fully open or fully closed.
When the gate remains partly open, high-velocity fluid and solids can pass across the gate and seat sealing surfaces. This can cause erosion, unstable flow, higher operating torque and premature trim damage.
Use a choke valve or control valve for continuous pressure reduction, flow adjustment or well-flow regulation.
9. What is the difference between a flat gate valve and a wedge gate valve?
A flat gate valve uses a parallel-sided gate that creates a straight through-conduit bore when fully open.
A wedge gate valve uses an angled or tapered disc that presses into matching seats. Wedge gate valves are more common in general pipelines, refineries and industrial piping systems.
API 6A wellhead and Christmas tree systems normally use flat or slab gate valves because they provide full-bore, high-pressure isolation.
10. Can SGPE supply a forged-body manual gate valve?
Yes. SGPE can supply forged-body API 6A manual gate valves for selected sizes, pressure classes, material classes and service conditions.
Forged construction often suits high-pressure, low-temperature, sour-service and other critical wellhead applications. Cast-body valves may suit selected standard configurations.
Working pressure, temperature, fluid composition, PSL, PR and NDE scope determine the most suitable body construction.
11. Can SGPE supply an OEM replacement FC gate valve?
Yes. SGPE can review and supply replacement FC gate valves, manual slab gate valves and internal spare parts for existing wellheads, Christmas trees, surface test trees and manifolds.
Provide the original manufacturer, model, serial number, nominal size, minimum bore, pressure rating, end connections and face-to-face length.
Nameplate photographs, connection photographs and original drawings help confirm compatibility.
12. What information should an RFQ for a manual wellhead gate valve include?
A complete RFQ should state the nominal size, minimum bore, rated working pressure, stem type, body construction, end connections, material class, temperature class, PSL, PR and sealing direction.
It should also include the service fluid, H₂S and CO₂ data, trim requirements, quantity, inspection scope, required documents and delivery destination.
For replacement valves, nameplate photographs, dimensions, connection details and available drawings help shorten the technical review and quotation process.
Request an API 6A Manual Flat Gate Valve Quotation
Customers can select rising-stem or non-rising-stem designs, forged or cast bodies, flanged, studded or threaded connections, metal-to-metal sealing, sour-service trim and OEM replacement configurations.
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