VALVES — DETAILED SUBCATEGORY PAGES
PAGE 1: GATE VALVES
Gate Valves
Linear-Motion Isolation Valves for On/Off Service
Gate valves are the most widely used isolation valve in the oil and gas industry. They provide a straight-through, unobstructed flow path when fully open, resulting in minimal pressure drop. A gate (wedge, slab, or parallel disc) moves perpendicular to the flow direction to open or close the valve.
Gate valves are designed for fully open or fully closed service. They are not intended for throttling—partially open gates experience vibration, erosion, and damage to seating surfaces.
Available Standards & Types
| Type | Standard | Key Features | Typical Application |
|---|---|---|---|
| Flexible Wedge Gate | API 600, ASME B16.34 | One-piece wedge with flex cut, self-adjusts to seats | Refinery isolation, steam, moderate temperatures |
| Solid Wedge Gate | API 600, ASME B16.34 | Simple, robust, one-piece wedge | General process isolation, moderate temps |
| Parallel Slide Gate | API 600 | Two parallel discs with spring, low seat friction | High-pressure steam, power generation |
| Through-Conduit Slab Gate | API 6D, API 6A | Full-bore, single slab, floating seats | Pipeline isolation, piggable lines |
| Expanding Gate | API 6D, API 6A | Positive mechanical expansion against both seats | Critical isolation, double block and bleed |
| Pressure-Seal Gate | API 600, ASME B16.34 | Bonnet seal tightens with pressure | High-pressure steam, boiler feedwater |
| Compact Gate (Small Bore) | API 602 | Compact design, threaded/socket-weld ends | Instrument isolation, drains, vents |
| API 6A Wellhead Gate | API 6A | Through-conduit slab, flanged or studded | Wellhead, Christmas tree, frac trees |
Size & Pressure Range
| Parameter | Range |
|---|---|
| Sizes | 1/2″ to 60″+ |
| Pressure Classes | 150# / 300# / 600# / 900# / 1500# / 2500# / 4500# |
| API 6A Ratings | 2,000 psi to 20,000 psi |
Body & Bonnet Designs
| Design | Description |
|---|---|
| Bolted Bonnet | Standard for most applications. Gasket seal between body and bonnet |
| Pressure-Seal Bonnet | Bonnet seal tightens as internal pressure increases. For high-pressure steam and boiler feedwater |
| Welded Bonnet | Body-bonnet joint welded. Used for buried service and where leakage is unacceptable |
| Union Bonnet | Threaded union between body and bonnet. Small-bore, instrument applications |
Material Options
| Service | Body/Bonnet | Trim (Wedge/Seat) | Stem |
|---|---|---|---|
| Sweet hydrocarbon | WCB (Carbon Steel) | 13Cr / 316 SS | 13Cr / 17-4PH |
| Sour service | WCB (NACE MR0175) | 316 SS / Duplex | 316 SS / Inconel 718 |
| High temperature | WC6 / WC9 (Cr-Mo) | Stellite Gr.6 | 316 SS |
| Cryogenic | LCB / LCC | 316 SS | 316 SS (extended bonnet) |
| Stainless / Corrosive | CF8M (316 SS) | 316 SS / Stellite | 316 SS |
| Seawater | Duplex / Super Duplex | Duplex / Super Duplex | Duplex |
Optional Features
- By-Pass Connection: Small-bore bypass line around gate to equalize pressure before opening
- Drain & Vent Connections: Flanged or threaded taps for draining cavity or venting
- Gear Operator: For sizes ≥8″ or high-pressure classes (reduces manual operating torque)
- Actuation: Pneumatic piston, electric multi-turn, hydraulic
- Fire-Safe Design: API 607 / API 6FA certified
- Double Block & Bleed (DBB): Two seating surfaces with bleed between
- Extended Bonnet: For cryogenic service to keep packing above freezing
- Live-Loaded Packing: Spring-loaded gland follower maintains packing compression through thermal cycles
PAGE 2: GLOBE VALVES
Globe Valves
Linear-Motion Valves for Throttling and Flow Regulation
Globe valves are specifically designed for flow regulation and throttling service. Unlike gate valves (which are on/off devices), globe valves use a plug-and-seat arrangement that provides precise control across a wide range of stem travel.
The S-shaped body creates inherent resistance to flow, which makes them ideal for control applications but less suitable where low pressure drop is critical.
Body Patterns
| Pattern | Description | Best For |
|---|---|---|
| T-Pattern (Straight) | Flow enters and exits in a straight line. Highest pressure drop | Standard throttling, process isolation |
| Y-Pattern | Inlet and outlet at roughly 45° angle to stem. Lower pressure drop | Higher flow applications, steam, erosion reduction |
| Angle Pattern | Inlet and outlet perpendicular. Combines valve + 90° elbow | Boiler blowdown, erosive fluids, piping simplification |
Disc / Plug Types
| Disc Type | Flow Characteristic | Application |
|---|---|---|
| Flat Disc | Quick opening | General on/off service |
| Needle Disc | Linear, fine adjustment | Small-bore precision throttling, sampling |
| V-Port Disc | Equal percentage | Proportional flow control |
| Parabolic / Contoured Disc | Modified equal percentage | Extended throttling range, reduced cavitation |
| Cage-Guided Plug | Linear or equal percentage | High-pressure drop, anti-cavitation |
Size & Pressure Range
| Parameter | Range |
|---|---|
| Sizes | 1/2″ to 24″ |
| Pressure Classes | 150# / 300# / 600# / 900# / 1500# / 2500# |
Flow Direction
Globe valves are typically unidirectional. The flow direction arrow cast on the body must be observed during installation.
| Flow Configuration | Application |
|---|---|
| Flow-to-Close (Over the Seat) | Standard for most applications |
| Flow-to-Open (Under the Seat) | Reduces hammering at near-closed position, but can cause instability near full open |
Typical Standards: API 602 (small-bore), API 623 (heavy-wall), BS 1873 (British), ASME B16.34
Material Options: As per Gate Valves material table above
PAGE 3: BALL VALVES
Ball Valves
Quarter-Turn Isolation with Tight Shutoff
Ball valves are the industry-preferred solution for rapid, reliable shutoff. A spherical ball with a central bore rotates 90 degrees from fully open to fully closed. Their quarter-turn operation makes them ideal for emergency shutdown (ESD), pipeline isolation, and applications requiring frequent cycling.
Ball Configurations
| Configuration | Description | Sizes | Pressure |
|---|---|---|---|
| Floating Ball | Ball not fixed; held against downstream seat by line pressure | Up to 6″-8″ | Up to 2500# |
| Trunnion-Mounted Ball | Ball supported by upper and lower trunnion bearings | 2″ to 60″+ | 150# to 4500# |
| Top Entry | Internals removable from top without removing valve from line | 2″ to 48″ | 150# to 2500# |
| Fully Welded | Body fully welded, no flange joints | 2″ to 48″ | 150# to 900# |
| V-Port / Segmented Ball | V-shaped or segmented ball for control applications | 1″ to 24″ | 150# to 600# |
Body Construction
| Type | Description | Application |
|---|---|---|
| Two-Piece | Body + end connector. Economical | Low to medium pressure, general service |
| Three-Piece | Two end connectors + body. Swing-out for in-line maintenance | Process piping, chemical service |
| Fully Welded (Forged Steel) | No body bolts. Zero leakage path | Buried gas pipelines, subsea |
Bore Types
| Bore | Description | Application |
|---|---|---|
| Full Bore (Full Port) | Bore diameter equals pipe ID. No flow restriction | Pipeline (piggable), slurry, high viscosity |
| Reduced Bore (Standard Port) | Bore diameter one pipe size smaller | General process isolation (cost-effective) |
| V-Port / Notched Bore | Shaped bore for control characteristic | Throttling, process control |
Seat Types
| Seat Material | Temperature Range | Application |
|---|---|---|
| PTFE (Virgin) | -50°C to +200°C | General process, chemicals |
| R-PTFE / TFM | -50°C to +260°C | Reinforced, better creep resistance |
| PEEK | -50°C to +260°C | High pressure, high temperature |
| Nylon / Devlon | -50°C to +120°C | High pressure, abrasive service |
| Metal Seated (Stellite / Tungsten Carbide) | -200°C to +1000°C | Extreme temperature, abrasion, slurry |
| Graphite-Filled PTFE | Up to +300°C | Fire-safe, high temperature |
Fire-Safe Certification
Fire-safe ball valves are tested to API 607 or API 6FA. In the event of a fire that destroys soft seats, secondary metal seats provide limited leakage to prevent escalation.
Typical Standards: API 6D (pipeline), API 608 (process), API 6A (wellhead), ISO 17292, API 607/6FA (fire-safe)
Optional Features:
- Double Block & Bleed (DBB): Two independent seating surfaces with cavity bleed
- Anti-Static Device: Electrical continuity between ball, stem, and body
- Locking Device: Mechanical lock in open or closed position
- Extension Stem: For buried or insulated applications
- Actuation: Pneumatic scotch yoke, rack & pinion, electric, hydraulic
PAGE 4: CHECK VALVES
Check Valves
Automatic Reverse Flow Prevention
Check valves are self-acting, one-directional valves that prevent reverse flow in piping systems. They open when forward flow exerts sufficient pressure and close automatically when flow stops or reverses. They are essential for protecting pumps, compressors, and process equipment from damage caused by backflow.
Check Valve Types
| Type | Standard | Key Features | Best For |
|---|---|---|---|
| Swing Check | ASME B16.34, API 6D | Hinged disc swings open/closed. Low pressure drop. Gravity-assisted closure | Horizontal lines, low pulsation, large diameters |
| Dual Plate / Double Door | API 594, API 6D | Two spring-loaded half-discs. Compact face-to-face. Lightweight | High-pressure gas, offshore, compact installations |
| Piston / Lift Check | ASME B16.34, API 6D | Guided piston lifts off seat. Spring-assisted closure | Vertical lines, pulsating flow, compressor discharge |
| Ball Check | BS 5153 | Simple ball and conical seat | Viscous fluids, slurry, sewage |
| Nozzle / Axial Flow | ASME B16.34 | Venturi body, axially guided disc. Ultra-fast closure, low pressure drop | Compressor stations, critical applications, gas pipelines |
| Tilting Disc | API 6D | Disc pivots slightly off-center. Self-aligning | Large-diameter water, low-pressure gas |
| Wafer Check | API 594 | Extremely short face-to-face. Fits between flanges | Space-constrained installations, general service |
| In-Line / Silent Check | ASME B16.34 | Internal spring-loaded poppet. Silent closure, no water hammer | Pump discharge, vertical lines |
Selection Criteria
| Factor | Best Check Type |
|---|---|
| Low pressure drop | Dual Plate, Nozzle/Axial Flow, Swing Check |
| Pulsating flow (reciprocating compressor) | Piston/Lift Check, Nozzle Check |
| Vertical pipe (flow upward) | Piston/Lift Check, In-Line Silent Check |
| Compact installation | Dual Plate, Wafer Check |
| Slurry / viscous fluid | Ball Check, Swing Check |
| Water hammer prevention | Nozzle Check, Silent Check, Dual Plate |
| Large diameter (>24″) | Swing Check, Tilting Disc |
| Subsea | Dual Plate, Swing Check (with special coatings) |
Closure Characteristics
| Behavior | Description | Best Type |
|---|---|---|
| Slow Closing | Relies on gravity and reverse flow | Swing Check |
| Fast Closing | Spring-assisted, closes before reverse flow develops | Dual Plate, Nozzle Check, Piston Check |
| Silent (Non-Slam) | Closes smoothly, no water hammer | Nozzle Check, Silent Check, Dual Plate |
Typical Standards: API 594 (wafer), API 6D (pipeline), ASME B16.34, API 598 (testing), BS 1868
Material Options:
- Body: WCB, LCB, CF8M, Duplex, Alloy 20
- Disc/Hinge: 316 SS, Duplex, Stellite, Inconel
- Seat: 13Cr, Stellite, PTFE (where applicable)
PAGE 5: BUTTERFLY VALVES
Butterfly Valves
Compact, Lightweight Quarter-Turn Valves for Large Diameters
Butterfly valves use a flat or profiled disc mounted on a shaft that rotates 90 degrees to control flow. Their principal advantages are compact face-to-face dimensions, light weight, and low cost—particularly in large diameters where gate or ball valves become impractical.
Valve Categories (API 609)
| Category | Design | Seat Type | Pressure/Temp Capability |
|---|---|---|---|
| Category A (Concentric) | One-piece resilient seat. Disc contacts seat along entire circumference | Soft (EPDM, NBR, PTFE) | Up to 600#, 180°C |
| Category B (Double Offset) | Two offsets reduce seat contact friction. Metal or soft seated | Soft or Fire-Safe Metal | Up to 900#, 800°C |
| Category B (Triple Offset) | Three offsets create torque-seated metal-to-metal seal | Metal Laminated / Solid Metal | Up to 1500#, 1000°C |
Offset Explained
| Offset | Description | Benefit |
|---|---|---|
| Concentric (Zero Offset) | Shaft centered in disc and body | Simple, lowest cost |
| Double Offset | Shaft behind disc centerline, off body centerline | Reduced seat wear, longer life |
| Triple Offset | Additional conical seat angle | Torque-seated metal seal, zero leakage, extreme temps |
Seat Materials
| Material | Max Temperature | Application |
|---|---|---|
| EPDM | 120°C | Water, mild chemicals |
| NBR (Nitrile) | 90°C | Hydrocarbon service, oil |
| Viton / FKM | 200°C | High temperature, chemicals, solvents |
| PTFE Lined | 200°C | Corrosive chemicals (requires flange-end body) |
| Metal (Stellite, Stainless) | 800-1000°C | High temperature, cryogenic, fire-safe |
Body Types
| Type | Description |
|---|---|
| Wafer | Fits between flanges. Most economical and common |
| Lug | Threaded lugs for bolt-through installation. Allows single-flange dead-end service |
| Double Flanged | Full body flanges on both sides. For demanding applications |
Typical Applications in Oil & Gas:
- Cooling water isolation (large bore)
- Firewater ring main isolation
- Seawater intake and outfall
- Air intake to compressors and turbines
- Tank vent and overflow lines
- Low-pressure steam and condensate
Typical Standards: API 609, ASME B16.34, API 607 (fire-safe)
PAGE 6: PLUG VALVES
Plug Valves
Quarter-Turn Valves for Slurries, Viscous Fluids, and Frequent Operation
Plug valves use a cylindrical or tapered plug with a through-bore that rotates 90 degrees to open or close. Their simple, robust design with no cavities makes them ideal for services where ball valves would clog or seize.
Plug Types
| Type | Description | Application |
|---|---|---|
| Lubricated Plug | Sealant injected between plug and body. Reduces torque, positive seal | Gas service (natural gas, LPG, sour gas) |
| Non-Lubricated / Sleeved | PTFE sleeve around plug eliminates sealant | Low-maintenance, chemical, water |
| Pressure-Balanced | Internal balance ports equalize pressure, reduce torque | High-pressure, frequent operation |
| Eccentric Plug | Plug offset from seat, no contact except at final closed position | Slurries, abrasive, throttling capable |
Plug Port Patterns
| Pattern | Description | Application |
|---|---|---|
| Rectangular Port | Maximum flow area, typical size 70-80% of pipe area | On/off isolation |
| Round Port | Full or reduced round bore | Piggable lines, critical isolation |
| Multi-Port (3-way, 4-way) | Divert or combine flow | Manifold, bypass, directional control |
Typical Applications in Oil & Gas:
- Produced water and drilling mud manifolds
- Oil sands slurry handling
- Chemical injection lines
- Gas gathering and distribution
- Tank drain and sampling points
Typical Standards: API 599, API 6D
PAGE 7: CHOKE VALVES
Choke Valves
High-Pressure Flow Control for Wellhead and Production
Choke valves are a specialized class of control valve designed to manage flow rate and reduce pressure from the wellhead. They operate under extreme conditions: high differential pressure, high velocity, erosive sand, and corrosive fluids.
Choke Types
| Type | Description | Best For |
|---|---|---|
| Fixed Bean (Positive Choke) | Solid orifice bean, replaceable. No moving parts | Steady, unvarying flow |
| Adjustable Choke | Needle & seat design. Externally adjustable flow | Variable flow, adjustable without shutdown |
| Cage-Guided Choke | Multi-stage pressure reduction through cage with drilled holes | High pressure drop, noise reduction, erosion control |
| Plug & Cage Choke | Plug moves within multi-port cage | Severe service, high turndown |
| Multi-Stage / Multi-Step Trim | Multiple pressure reduction stages | Choke-to-tank (atmospheric discharge), very high ΔP |
Trim Materials (Erosion Resistance is Critical)
| Material | Application |
|---|---|
| Stellite 6 / 12 | Standard trim, moderate erosion |
| Tungsten Carbide | Severe erosion, sand production, high-velocity gas |
| Silicon Carbide / Ceramic | Extreme erosion, longest service life |
| Inconel 718 | High temperature, sour service, high strength |
Actuation Options
- Manual (handwheel with position indicator)
- Pneumatic stepper for remote adjustment
- Hydraulic for subsea
Typical Standards: API 6A
Pressure Ratings: 2,000 to 20,000 psi
Sizes: 1″ to 6″ (trim size determined by flow coefficient Cv requirement)
PAGE 8: CONTROL VALVES
Control Valves
Automated Process Control for Pressure, Flow, Level, and Temperature
Control valves are the final control element in process automation loops. Combined with an actuator, positioner, and accessories, they modulate flow to maintain precise process conditions as dictated by the plant control system (DCS/PLC).
Control Valve Bodies
| Body Type | Flow Characteristic | Application |
|---|---|---|
| Globe (Single-Port) | Linear or equal percentage | General process control, wide rangeability |
| Globe (Cage-Guided) | Linear or equal percentage | High pressure drop, reduced noise trim available |
| Angle | Linear | Erosive or flashing service, combines valve + elbow |
| Rotary (V-Ball / Segmented Ball) | Equal percentage | High capacity, compact, lower cost |
| Eccentric Plug | Linear or equal percentage | Slurries, viscous, abrasive |
| Axial Flow | Linear or equal percentage | Low noise, high capacity, compact |
| Three-Way | Linear | Mixing or diverting service |
Trim Designs
| Trim Type | Key Feature | Application |
|---|---|---|
| Standard / Unbalanced | Simple, reliable | Clean fluids, moderate pressure drop |
| Pressure-Balanced | Reduced actuator force required | High pressure drop, large sizes |
| Cage-Guided | Trim accessible from top, multiple cage options | Standard for globe control valves |
| Anti-Cavitation | Multi-stage or tortuous path | High-pressure drop with liquids (prevents cavitation damage) |
| Low Noise | Drilled/slotted cages, diffusers, splitters | Gas service where noise exceeds 85 dBA |
| High Turndown | Special plug profiles | Flow rangeability >50:1 |
Actuator Types
| Actuator | Control Signal | Fail Mode | Application |
|---|---|---|---|
| Pneumatic Spring & Diaphragm | 3-15 psi (pneumatic) | Fail-Open / Fail-Close / Fail-Last | Most common. Reliable, cost-effective |
| Pneumatic Piston | 3-15 psi or electro-pneumatic | Fail-Open / Fail-Close | High thrust, large valves |
| Electric (Smart Electric) | 4-20mA / Modbus / Fieldbus | Programmable | Remote locations, no instrument air |
| Electro-Hydraulic | 4-20mA + hydraulic power | Programmable | Subsea, high force, remote |
Positioners & Accessories
- I/P Positioner: Converts 4-20mA electrical signal to pneumatic output
- Smart Positioner: Digital control, HART/Fieldbus/Profibus, diagnostics, partial stroke testing
- Limit Switches: Open/closed position feedback
- Solenoid Valves: For emergency fail-safe actuation
- Airset / Filter Regulator: Clean, regulated instrument air supply
- Volume Booster: Faster stroke times for large actuators
Typical Standards: ISA-75 (valve sizing), IEC 60534 (noise prediction, flow testing), API 6D (pipeline control valves), NACE MR0175 (sour service)
PAGE 9: SAFETY & RELIEF VALVES
Safety & Relief Valves
Overpressure Protection for Pressure Vessels, Piping, and Equipment
Safety and relief valves are the last line of defense against catastrophic overpressure. They automatically open at a predetermined set pressure and discharge sufficient fluid to prevent pressure from exceeding allowable limits. They are mandated by code (ASME, API, PED) for all pressure-containing equipment.
Valve Types
| Type | Action | Fluid Service | Best For |
|---|---|---|---|
| Spring-Loaded Safety Valve | Popping action (rapid full opening) | Compressible (gas, steam) | Boilers, gas vessels, steam systems |
| Spring-Loaded Relief Valve | Gradual opening proportional to overpressure | Incompressible (liquid) | Thermal relief, liquid-filled vessels |
| Pilot-Operated Safety-Relief Valve | Pilot valve senses pressure, controls main valve | Gas or liquid | Tight shutoff to set pressure, critical service |
Pilot-Operated PRV Advantages
| Feature | Benefit |
|---|---|
| Tight Shutoff to Set Point | No simmering or leakage at 95-98% of set pressure. Saves product loss |
| Full Lift at Set Pressure | Instant full capacity, no overpressure required for full lift |
| Remote Sensing | Pilot senses pressure at vessel, not at valve inlet. Compensates for inlet pressure drop |
| Backpressure Compensation | Balanced pilot compensates for fluctuating discharge backpressure |
| Field Test Connection | Allows in-situ set pressure verification without removing valve |
| Modulating Action | Opens only as much as needed to relieve the upset. Reduces product loss |
Typical Standards:
- API 526 — Flanged steel safety relief valves (standardized orifice areas)
- ASME Section VIII — Pressure vessel code requiring overpressure protection
- ASME Section I — Boiler code
- API 520 Part I & II — Sizing, selection, and installation
- API 521 — Pressure relieving and depressuring systems
Orifice Designations (API 526)
| Orifice Letter | Effective Area (sq in) | Typical Flow Range |
|---|---|---|
| D | 0.110 | Small vessels, thermal relief |
| E | 0.196 | Process vent |
| F | 0.307 | Small to medium vessels |
| G | 0.503 | Medium process vessels |
| H | 0.785 | Large process vessels |
| J | 1.287 | Large vessels, gas plants |
| K | 1.838 | High-capacity gas service |
| L | 2.853 | High-capacity, steam |
| M | 3.600 | Very high capacity |
| N | 4.340 | Maximum area, large equipment |
| P | 6.380 | Critical large-capacity service |
PAGE 10: WELLHEAD & CHRISTMAS TREE VALVES
Wellhead & Christmas Tree Valves
Surface Flow Control for Drilling, Completion, and Production
Wellhead and Christmas tree valves control hydrocarbon flow at the surface termination of a well. They are designed and manufactured to API 6A, the most demanding valve standard in the oil and gas industry, covering extreme pressures, sour service, and high/low temperature extremes.
API 6A Valve Types
| Valve | Configuration | Function |
|---|---|---|
| Master Valve | Gate (Through-Conduit Slab) | Primary isolation valve at the base of the Christmas tree. Normally open, closed for well kill or intervention |
| Wing Valve | Gate or Ball | Flowline isolation. Used for shutting in or opening production flow |
| Swab / Crown Valve | Gate | Access to the vertical bore for wireline, slickline, and intervention |
| Subsurface Safety Valve (SSSV) | Flapper or Ball | Fail-safe closed valve set deep in the wellbore. Surface or subsurface controlled |
| Surface Safety Valve (SSV) | Gate + Actuator | Fail-safe closed on loss of control signal. Emergency shutdown at surface |
| Check Valve | API 6A Check | Prevents backflow from flowline into wellbore |
API 6A Classification
| Classification | Parameter | Options |
|---|---|---|
| Pressure Rating | Maximum working pressure | 2,000 / 3,000 / 5,000 / 10,000 / 15,000 / 20,000 psi |
| Material Class | Service suitability | AA (General) / BB / CC / DD / EE / FF / HH (Severe Sour Service) |
| Temperature Class | Operating temperature range | K (-60°C to +82°C) / L / P / R / S / T / U / X / Y (+345°C) |
| Product Specification Level (PSL) | Quality/Testing Rigor | PSL 1 to PSL 4 |
PSL Levels Explained
| PSL | Testing Level | Application |
|---|---|---|
| PSL 1 | Basic | Low-risk, sweet, moderate pressure |
| PSL 2 | Standard | General oil and gas |
| PSL 3 | Enhanced | High-pressure, sweet/sour, offshore |
| PSL 3G | PSL3 + Gas Testing | Gas service, critical applications |
| PSL 4 | Maximum | Extreme pressure, HPHT, critical sour service |
Material Classes for Sour Service
| Material Class | Max H2S Partial Pressure | Trim Requirements |
|---|---|---|
| AA | General (Sweet) | Standard |
| BB | Moderate Sour | 316 SS, controlled hardness |
| CC | High Sour | Duplex, Inconel 718 |
| HH | Severe Sour | Inconel 718, Inconel 625 cladding, CRA trim |
Typical Standards: API 6A (Specification for Wellhead and Christmas Tree Equipment), API 6AV1 (Actuator Qualification), NACE MR0175 / ISO 15156