Metal Bonnet Seal Rings for F and FC Gate Valves

Description

Goldenman manufactures metal Bonnet Seal Rings for F-, FC-, FL- and FLS-style API 6A Gate Valves used in wellheads, Christmas Trees, choke and kill manifolds, production manifolds and high-pressure flow-control systems.

The Bonnet Seal Ring is installed between the valve body and bonnet. When the bonnet bolting is tightened, the metal ring is compressed between two precision-machined sealing surfaces to form a pressure-resistant static barrier.

The product range covers:

• Valve bores from 1-13/16 to 7-1/16 in
• Pressure classes from 2,000 to 15,000 psi
• Flat Bonnet Seal Rings
• Type A grooved Bonnet Seal Rings
• Type B Bonnet Seal Rings
• Low-carbon-steel configurations
• 304 and 316 stainless-steel configurations
• Standard- and sour-service trim
• Manual and hydraulic Gate Valve assemblies
• Individual replacement rings
• Complete bonnet and valve overhaul seal kits

Each ring is manufactured according to the valve style, nominal bore, working pressure, bonnet-groove profile, seal cross-section, material class and temperature class.

Product Short Description

Goldenman FC Gate Valve Bonnet Seal Rings provide the static metal seal between the valve body and bonnet.

Precision-controlled outside diameter, inside diameter, thickness, cross-section and surface finish allow the ring to deform uniformly when the bonnet is assembled and tightened.

Flat, Type A and Type B configurations are available for low-, medium- and high-pressure F, FC, FL and FLS Gate Valves. Bonnet Seal Rings are supplied individually or as part of a complete valve repair kit containing stem packing, seat seals, bonnet seals, backup rings and O-rings.

Product Highlights

• Metal Bonnet Seal Rings for API 6A Gate Valves
• F-, FC-, FL- and FLS-style valve applications
• Valve sizes from 1-13/16 to 7-1/16 in
• Pressure classes from 2,000 to 15,000 psi
• Flat, Type A and Type B profiles
• Grooved and non-grooved configurations
• Low-carbon-steel and stainless-steel materials
• 304 and 316 stainless-steel options
• Standard and H₂S-service material packages
• Manual and hydraulically actuated valve applications
• Controlled plastic deformation during assembly
• Precision-machined sealing surfaces
• Controlled ring thickness and flatness
• Matching body and bonnet groove profiles
• Corrosion-resistant surface options
• Material and batch traceability
• Dimensional and visual inspection
• Individual protective packaging
• Complete bonnet and valve seal kits
• Replacement by valve model, size, pressure or part number

General Technical Specifications

Parameter	Available Configuration
Product	Gate Valve Bonnet Seal Ring
Alternative names	Bonnet Gasket, Bonnet Metal Seal, Body-to-Bonnet Seal Ring
Valve styles	F, FC, FL and FLS
Applicable equipment standard	API Spec 6A
Valve operation	Manual and hydraulic
Nominal bore range	1-13/16–7-1/16 in
Parent-valve pressure range	2,000–15,000 psi
Seal profiles	Flat, Type A and Type B
Profile options	Grooved and non-grooved
Main materials	Low-carbon steel, 304 stainless steel and 316 stainless steel
Special materials	17-4PH and nickel-alloy configurations
Surface protection	Zinc plating, silver plating, soft metallic coating or uncoated stainless steel
Service	Oil, gas, water, drilling fluid, completion fluid and injection service
Sour service	H₂S-service material configurations
Temperature classes	API 6A temperature-class configurations
Identification	Valve type, bore, pressure, profile and part number
Supply form	Ring only or complete valve seal kit
Inspection	Material, dimensional, surface-finish and visual inspection
Packaging	Individually wrapped and permanently identified

Standard Valve Compatibility Range

Flat Bonnet Seal Rings for 2,000 and 5,000 PSI Valves

Valve Style	Nominal Bore	Pressure Class	Seal Profile	Material Options
F / FC / FL	2-1/16 in	2,000 and 5,000 psi	Flat	Low-carbon steel / 316 SS
F / FC / FL	2-9/16 in	2,000 and 5,000 psi	Flat	Low-carbon steel / 316 SS
F / FC / FL	3-1/8 in	2,000 and 5,000 psi	Flat	Low-carbon steel / 316 SS
F / FC / FL / FLS	4-1/16 in	2,000 and 5,000 psi	Flat	Low-carbon steel / 316 SS
F / FC / FL	6-3/8 in	2,000 and 5,000 psi	Flat	Low-carbon steel / 316 SS
F / FC / FL	7-1/16 in	2,000 and 5,000 psi	Flat	Low-carbon steel / 316 SS

Type A Bonnet Seal Rings

Valve Style	Nominal Bore	Pressure Class	Seal Profile	Standard Material
FC	1-13/16 in	10,000 and 15,000 psi	Type A with groove	316 SS
F / FC	2-9/16 in	10,000 psi	Type A with groove	316 SS
FC	2-9/16 in	15,000 psi	Type A with groove	316 SS
FC	3-1/16 in	15,000 psi	Type A with groove	316 SS

Type B Bonnet Seal Rings

Valve Style	Nominal Bore	Pressure Class	Seal Profile	Standard Material
F / FC / FL / FLS	2-1/16 in	10,000 and 15,000 psi	Type B	316 SS
F / FC	2-9/16 in	10,000 and 15,000 psi	Type B	316 SS
F / FC	3-1/16 in	10,000 psi	Type B	316 SS
F / FL / FLS	3-1/16 in	15,000 psi	Type B	316 SS
F / FC	4-1/16 in	10,000 and 15,000 psi	Type B	316 SS
FLS / FLS-R	4-1/16 in	15,000 psi	Type B severe-service profile	316 SS

What Is a Gate Valve Bonnet Seal Ring?

The Bonnet Seal Ring is a static metal sealing component located between the valve body and bonnet.

Its primary functions are:

• Containing internal valve pressure
• Sealing the body-to-bonnet connection
• Preventing external fluid leakage
• Maintaining sealing integrity during pressure cycling
• Withstanding thermal expansion and contraction
• Protecting the bonnet cavity from external contamination
• Supporting safe valve operation after maintenance

The ring is compressed when the bonnet bolts or studs are tightened.

The controlled assembly load causes limited plastic deformation at the ring’s sealing contact areas. This creates close metal-to-metal contact with the body and bonnet grooves.

Bonnet Seal Ring vs Flange Ring Gasket

A Bonnet Seal Ring and an API flange ring gasket perform different functions.

Feature	Bonnet Seal Ring	R, RX or BX Ring Gasket
Installation location	Between Gate Valve body and bonnet	Between two API or ASME flanges
Primary application	Internal valve assembly	External flange connection
Geometry	Valve-specific Flat, Type A or Type B	Standard R, RX or BX number
Selection basis	Valve style, bore, pressure and bonnet groove	Flange size, pressure and ring-groove number
Example	FC 2-1/16 in 10,000 psi Type B	BX-152 or RX-54 flange gasket
Interchangeability	Valve-design-specific	Flange-standard-specific

An RX-54, BX-152 or other standard flange ring gasket does not replace an FC Gate Valve Bonnet Seal Ring unless the valve drawing specifically uses that standard ring profile.

Flat Bonnet Seal Ring

Flat Bonnet Seal Rings are used mainly in F-, FC- and FL-style Gate Valves with 2,000 and 5,000 psi pressure classes.

The ring has:

• Flat annular geometry
• Controlled inside diameter
• Controlled outside diameter
• Controlled thickness
• Smooth upper and lower sealing surfaces
• Rounded or chamfered edges
• Uniform material hardness

Flat seal rings are manufactured from:

• Low-carbon steel for standard service
• 304 stainless steel for corrosion resistance
• 316 stainless steel for corrosive and sour environments

The relatively soft metal compresses between the valve body and bonnet surfaces to create the static pressure seal.

Type A Bonnet Seal Ring

Type A Bonnet Seal Rings use a profiled cross-section and a locating groove.

The groove controls:

• Ring orientation
• Seal position
• Contact concentration
• Initial compression
• Metal deformation
• Stability during bonnet assembly

Type A rings are used in selected high-pressure FC and F Gate Valve configurations.

They are manufactured primarily from 316 stainless steel for resistance to corrosion, produced fluids and H₂S-containing environments.

Type B Bonnet Seal Ring

Type B Bonnet Seal Rings are used in many 10,000 and 15,000 psi F-, FC-, FL- and FLS-style Gate Valves.

The profile provides:

• Concentrated sealing contact
• Controlled compression
• Stable radial positioning
• Resistance to extrusion
• High-pressure containment
• Reliable pressure cycling

Type B configurations are supplied in grooved, non-grooved, stepped and non-stepped versions according to the valve design.

A Type B ring is matched to the exact body and bonnet sealing profile.

Metal Seal Operating Principle

The body and bonnet contain matching machined sealing surfaces.

During assembly:

1. The Bonnet Seal Ring is installed in the body or bonnet groove.
2. The bonnet is lowered into position.
3. Bonnet studs and nuts are installed.
4. The bolting is tightened in a controlled cross pattern.
5. The seal ring is compressed between the body and bonnet.
6. The metal contact surfaces deform locally.
7. A continuous pressure barrier forms around the valve bore.

Internal pressure increases the sealing contact in pressure-energized profiles.

The sealing mechanism does not depend on a soft elastomer alone, allowing the body-to-bonnet connection to operate under high pressure, thermal cycling and aggressive fluid conditions.

Material Options

Low-Carbon Steel

Low-carbon steel Bonnet Seal Rings provide:

• Controlled compressibility
• Uniform plastic deformation
• Cost-effective standard-service sealing
• Reliable performance in non-corrosive environments
• Compatibility with 2,000 and 5,000 psi Flat seal designs

Available surface protection includes zinc plating, phosphate coating and soft metallic coatings.

304 Stainless Steel

304 stainless steel provides:

• General corrosion resistance
• Resistance to water-based fluids
• Clean machined sealing surfaces
• Stable mechanical properties
• Improved storage resistance

It is used in standard oil, gas and water-service valves.

316 Stainless Steel

316 stainless steel provides:

• Improved chloride resistance
• Resistance to produced water
• Resistance to many completion fluids
• Corrosion resistance in offshore service
• Suitability for high-pressure Type A and Type B rings
• Compatibility with sour-service material packages

316 stainless steel is the primary material for 10,000 and 15,000 psi Bonnet Seal Rings.

17-4PH Stainless Steel

17-4PH stainless steel provides:

• High mechanical strength
• Dimensional stability
• Corrosion resistance
• Controlled heat-treated properties
• High-pressure severe-service capability

It is used in project-specific high-strength seal configurations.

Nickel-Alloy Materials

Nickel-alloy rings are supplied for:

• Severe sour gas
• High CO₂ concentration
• High chloride exposure
• Chemical injection service
• High-temperature corrosive fluids
• Offshore and subsea environments

Available materials include Alloy 625 and equivalent corrosion-resistant alloys.

Surface Coatings

Metallic coatings support seal installation, reduce galling and protect the ring during storage.

Available finishes include:

• Zinc plating
• Silver plating
• Soft iron coating
• Copper plating
• Phosphate coating
• Dry-film lubricant
• Uncoated stainless-steel finish

Coating thickness is controlled to preserve the ring’s finished dimensions and sealing geometry.

Standard-Service Configuration

Standard-service Bonnet Seal Rings are used with:

• Crude oil
• Natural gas
• Produced water
• Fresh water
• Drilling mud
• Completion fluid
• Workover fluid
• Injection water

The standard package uses low-carbon steel, 304 stainless steel or 316 stainless steel according to the pressure class and valve design.

Sour-Service Configuration

Sour-service Bonnet Seal Rings are supplied for H₂S-containing well fluids.

The sour-service package includes:

• 316 stainless steel or nickel-alloy material
• Controlled hardness
• Corrosion-resistant surface condition
• Heat and batch traceability
• Material certificates
• Dimensional inspection records
• Individually identified packaging

The ring is supplied as part of a complete sour-service valve sealing system that includes compatible seats, stem packing, bonnet seals and backup rings.

Low-Temperature Configuration

Low-temperature seal packages include:

• Impact-compatible metallic materials
• Low-temperature surface coatings
• Matched low-temperature stem packing
• Low-temperature seat seals
• Low-temperature bonnet seals
• Cold-service assembly lubricant

The Bonnet Seal Ring maintains dimensional stability during contraction of the valve body and bonnet.

High-Temperature Configuration

High-temperature packages use:

• Stainless-steel or nickel-alloy Bonnet Seal Rings
• FKM or high-temperature stem seals
• PEEK backup rings
• High-temperature seat seals
• Temperature-stable assembly lubricant

The metal Bonnet Seal Ring remains the primary static body-to-bonnet pressure barrier.

F and FC Gate Valve Applications

Bonnet Seal Rings are used in:

• Manual F Gate Valves
• Manual FC Gate Valves
• Hydraulic FC Gate Valves
• FL Gate Valves
• FLS Gate Valves
• FLS-R Gate Valves
• Christmas Tree master valves
• Wing valves
• Swab valves
• Kill wing valves
• Wellhead outlet valves
• Choke manifolds
• Kill manifolds
• Production manifolds
• Injection manifolds
• Frac manifolds
• Well-testing equipment
• Workover pressure-control systems

Complete Bonnet Seal Kit

Goldenman supplies complete bonnet sealing kits containing:

• Metal Bonnet Seal Ring
• Primary stem packing
• Secondary stem packing
• Packing gland seal
• Bonnet O-rings
• Stem wiper
• Lantern ring
• PTFE backup rings
• PEEK backup rings
• Grease-fitting seals
• Packing-injection-fitting seals
• Bonnet stud and nut set
• Assembly lubricant

Each kit is packaged and marked for one valve size, pressure class and service condition.

Complete Gate Valve Overhaul Kit

The complete Gate Valve overhaul kit includes:

• Slab gate
• Two valve seats
• Seat body seals
• Seat backup rings
• Bonnet Seal Ring
• Valve stem
• Stem packing
• Bonnet O-rings
• Gate pin or stem adapter
• Bearings and races
• Handwheel seals
• Grease-fitting seals
• Sealant-injection-fitting seals
• Bonnet studs and nuts
• Valve identification tag

Manual and hydraulic valve kits use separate stem, bonnet and actuator sealing components.

Replacement Identification

A replacement Bonnet Seal Ring is identified using:

• Valve manufacturer
• Valve style
• Manual or hydraulic operation
• Nominal bore
• Working-pressure class
• Bonnet design
• Flat, Type A or Type B profile
• Grooved or non-grooved profile
• Inside diameter
• Outside diameter
• Finished thickness
• Cross-section dimensions
• Existing part number
• Material class
• Temperature class
• Standard or sour service

The exact valve configuration remains the primary identification method.

Critical Dimensions

Each Bonnet Seal Ring drawing includes:

• Outside diameter
• Inside diameter
• Ring thickness
• Cross-section width
• Sealing-contact width
• Groove dimensions
• Step height
• Edge radius
• Chamfer dimensions
• Flatness tolerance
• Parallelism tolerance
• Surface-finish requirement

Dimensional control ensures uniform compression around the complete body-to-bonnet connection.

Installation Procedure

1. Isolate and fully depressurize the Gate Valve.
2. Drain and clean the body cavity.
3. Remove the actuator, handwheel or stem operating assembly.
4. Loosen and remove the bonnet bolting.
5. Lift the bonnet vertically from the valve body.
6. Remove the used Bonnet Seal Ring.
7. Clean the body and bonnet sealing grooves.
8. Inspect the grooves for corrosion, scoring and mechanical damage.
9. Clean the new seal ring without scratching its surfaces.
10. Install the ring in the correct orientation.
11. Lower the bonnet evenly onto the valve body.
12. Install the bonnet studs and nuts.
13. Tighten the bolting in a controlled cross pattern.
14. Reassemble the valve operating components.
15. Complete low- and high-pressure body and seat tests.

A used metal Bonnet Seal Ring is not reinstalled after bonnet disassembly.

Body and Bonnet Groove Inspection

The sealing grooves are inspected for:

• Corrosion
• Pitting
• Scratches
• Radial scoring
• Impact marks
• Deformation
• Embedded debris
• Previous coating residue
• Incorrect surface finish
• Loss of dimensional tolerance

A clean and dimensionally correct groove allows the new ring to deform uniformly and establish full circumferential sealing contact.

Causes of Bonnet Leakage

Reusing the Old Metal Ring

A metal Bonnet Seal Ring retains the deformation created during its first installation. Reuse prevents uniform compression and increases the risk of leakage.

Incorrect Seal Profile

Flat, Type A and Type B rings use different sealing geometries. An incorrect profile does not contact the body and bonnet grooves correctly.

Incorrect Dimensions

A ring with an incorrect ID, OD or thickness produces insufficient compression, excessive compression or misalignment.

Damaged Sealing Groove

Corrosion, scoring and impact damage create leakage paths around the metal ring.

Uneven Bonnet Tightening

Uneven tightening tilts the bonnet and produces nonuniform compression.

Contaminated Sealing Surfaces

Grease, dirt, rust and metal particles prevent direct contact between the ring and sealing grooves.

Incorrect Ring Material

Fluid corrosion, temperature and H₂S exposure can damage an unsuitable metallic material.

Excessive Pressure or Temperature

Operation outside the valve’s rated envelope affects bonnet bolting, sealing contact and valve-body deformation.

Inspection and Replacement Criteria

Replace the Bonnet Seal Ring when:

• The bonnet has been removed
• External leakage appears at the body-to-bonnet joint
• The ring has visible compression marks
• Corrosion or pitting is present
• The ring is bent or distorted
• The surface coating is damaged
• Valve overhaul is completed
• The valve service class changes
• The pressure or temperature configuration changes

A new Bonnet Seal Ring is installed during every body-to-bonnet disassembly.

Manufacturing Process

Goldenman manufacturing includes:

1. Raw-material verification
2. Heat- or batch-number assignment
3. Cutting or ring-blank preparation
4. Rough machining
5. Heat treatment where required
6. Finish machining
7. Profile and groove machining
8. Surface finishing
9. Plating or coating
10. Dimensional inspection
11. Flatness and parallelism inspection
12. Surface-finish inspection
13. Visual inspection
14. Cleaning and preservation
15. Permanent identification
16. Individual packaging
17. Final documentation review

Quality Control

Quality control includes:

• Material certificate verification
• Chemical-composition review
• Heat and batch traceability
• Hardness testing
• Outside-diameter inspection
• Inside-diameter inspection
• Thickness measurement
• Profile inspection
• Groove inspection
• Flatness measurement
• Parallelism measurement
• Surface-roughness inspection
• Coating-thickness inspection
• Visual surface inspection
• Final part-number verification
• Packaging inspection

Each production batch is checked against the approved valve-seal drawing.

Valve Pressure Testing After Installation

A rebuilt valve undergoes:

• Low-pressure body test
• High-pressure body test
• Upstream seat test
• Downstream seat test
• Bidirectional seat test
• Stem packing test
• Body-to-bonnet external leakage inspection
• Full opening and closing cycle
• Manual or hydraulic actuator test

The Bonnet Seal Ring is evaluated as part of the complete assembled valve pressure boundary.

Product Documentation

The supply package includes:

• Certificate of Conformity
• Product datasheet
• Bonnet Seal Ring drawing
• Valve compatibility list
• Material certificate
• EN 10204 3.1 certificate
• Heat-treatment record
• Hardness report
• Dimensional inspection report
• Surface-finish report
• Coating report
• Batch traceability record
• Packing list
• Third-party inspection report

Complete valve repair kits include component lists and seal-location drawings.

Packaging and Storage

Each Bonnet Seal Ring is:

• Individually wrapped
• Protected from metal-to-metal contact
• Marked with valve size and pressure class
• Identified by seal profile
• Protected from corrosion
• Packed in a rigid box or divided carton

Storage conditions include:

• Clean indoor environment
• Dry atmosphere
• Protection from impact
• Protection from corrosive chemicals
• Original sealed packaging
• Separation by part number and material

The ring remains in its protective packaging until valve assembly.

Frequently Asked Questions

Is this an RX or BX Ring Gasket?

No.

This product is a valve-specific Bonnet Seal Ring installed between the Gate Valve body and bonnet.

RX and BX Ring Gaskets are used between API flange connections.

What is the difference between a Bonnet Gasket and a Bonnet Seal Ring?

Both terms refer to the body-to-bonnet sealing component.

“Bonnet Seal Ring” is the more precise term for the metal sealing component used in F and FC Gate Valves.

What valve types use these rings?

The range covers F-, FC-, FL- and FLS-style manual and hydraulic Gate Valves.

What sizes are available?

Available valve bore sizes range from 1-13/16 to 7-1/16 inches.

What pressure ratings are available?

Bonnet Seal Rings are supplied for 2,000, 5,000, 10,000 and 15,000 psi Gate Valves.

What is the difference between Flat, Type A and Type B rings?

Flat rings use a simple annular profile for many 2,000 and 5,000 psi valves.

Type A rings use a profiled, grooved geometry for selected high-pressure FC valves.

Type B rings use a high-pressure profiled geometry for many 10,000 and 15,000 psi F, FC, FL and FLS valves.

Can a Type A ring replace a Type B ring?

No.

The two profiles use different body and bonnet sealing grooves.

Can the old Bonnet Seal Ring be reused?

No.

The ring plastically deforms during the original valve assembly and is replaced whenever the bonnet is removed.

Which material is used for 10,000 and 15,000 psi valves?

316 stainless steel is the standard material for most Type A and Type B high-pressure Bonnet Seal Rings.

Are sour-service rings available?

Yes.

Sour-service configurations use 316 stainless steel or nickel-alloy materials with full material and batch traceability.

Does valve bore alone identify the ring?

No.

The valve style, bore, pressure class and Bonnet Seal Ring profile identify the correct component.

Are complete valve repair kits available?

Yes.

Goldenman supplies bonnet seal kits and complete overhaul kits for manual and hydraulic F, FC, FL and FLS Gate Valves.

Can a replacement be manufactured from a sample?

Yes.

A replacement is produced from an unused sample, dimensional drawing, existing part number or verified valve body and bonnet measurements.

Information Required for Quotation

Please provide:

• Valve manufacturer
• Valve style: F, FC, FL or FLS
• Manual or hydraulic operation
• Nominal bore
• Working-pressure class
• Flat, Type A or Type B profile
• Grooved or non-grooved configuration
• Existing part number
• Bonnet Seal Ring ID
• Bonnet Seal Ring OD
• Finished thickness
• Cross-section dimensions
• Body-groove dimensions
• Bonnet-groove dimensions
• Material class
• Temperature class
• Standard or H₂S service
• Required material
• Required coating
• Ring only or complete seal kit
• Required quantity
• Existing drawing or sample
• Inspection requirements
• Documentation requirements
• Destination country
• Delivery schedule

Request a Technical Quotation

Goldenman supplies metal Bonnet Seal Rings and complete repair kits for F-, FC-, FL- and FLS-style API 6A Gate Valves.

The product range covers valve bores from 1-13/16 to 7-1/16 inches, pressure classes from 2,000 to 15,000 psi, and Flat, Type A and Type B seal profiles.

Individual rings and complete valve overhaul kits are supplied with dimensional drawings, material certificates, batch traceability and inspection records.

Email: info@goldenman.com