Reliable access systems for corrosion monitoring, coupon exposure, probe installation, and online retrieval in pressurised process systems.
Product Overview
Our Corrosion Access Fitting / Coupon Holder / Probe system provides a safe and practical interface for corrosion monitoring in pipelines, vessels, and pressurised process equipment. The access fitting allows corrosion coupons, electrical resistance probes, linear polarisation resistance probes, hydrogen probes, erosion probes, and other monitoring devices to be installed, inspected, retrieved, or replaced with suitable service valves and retrieval tools.
Key Features
- Designed for corrosion coupon exposure, probe insertion, erosion monitoring, hydrogen monitoring, and process access applications.
- Available in flanged, flarweld, butt-weld, socket-weld, and threaded connection styles.
- Supports solid plug, hollow plug, coupon holder, probe adapter, injection, sampling, and monitoring configurations.
- Suitable for online installation and retrieval when used with compatible service valve and retriever assemblies.
- Designed for pressure containment, sealing integrity, and safe access to pressurised systems.
- Material options available for carbon steel, low-temperature carbon steel, stainless steel, duplex, super duplex, and nickel alloy service.
Typical Applications
- Oil and gas production pipelines
- Gas processing plants and offshore platforms
- Refinery and petrochemical process lines
- Water injection, produced water, and seawater systems
- Chemical processing and utility systems
- Corrosion inhibitor performance monitoring
- Sour service and H2S-containing environments where suitable materials are specified
- Pipeline integrity management and corrosion rate assessment programmes
Available Configurations
Configuration |
Description |
Best For |
Access Fitting Body |
Permanent pressure-retaining body installed on pipeline or vessel to provide access for corrosion monitoring devices. |
Long-term corrosion monitoring points in pressurised process systems. |
Solid Plug Assembly |
Pressure-retaining plug used to seal the access fitting when no through-bore probe is required. |
Coupon holder installations and blanking applications. |
Hollow Plug Assembly |
Through-bore plug arrangement for probes, injection tubes, sampling devices, or other inserted instruments. |
Electrical probes, LPR probes, ER probes, hydrogen probes, and injection applications. |
Coupon Holder |
Holds corrosion coupons in the process stream for exposure and later weight-loss analysis. |
Corrosion rate measurement and material compatibility monitoring. |
Corrosion Probe |
Instrumented probe used for online or periodic corrosion monitoring. |
Real-time or periodic corrosion trend monitoring. |
Service Valve and Retriever |
Used to isolate, equalise, insert, and retrieve plugs, coupons, or probes under controlled conditions. |
Online retrieval without process shutdown, subject to system design and operating procedure. |
Technical Specifications
Parameter |
Typical Options |
Product Type |
Corrosion access fitting, coupon holder, probe holder, probe assembly, service valve, and retriever accessory |
Nominal Access Size |
Commonly 2 inch nominal access system; other project-specific sizes available upon request |
Connection Type |
Flanged RF / RTJ, flarweld, butt-weld, socket-weld, threaded NPT, or custom connection |
Pressure Rating |
Designed to suit project pressure class and client specification; high-pressure options available |
Temperature Rating |
Dependent on material, sealing system, plug type, probe type, and process conditions |
Monitoring Devices |
Strip coupon, flush disc coupon, rod coupon, ladder coupon, ER probe, LPR probe, hydrogen probe, erosion probe, injection tube, or sampling device |
Plug Type |
Solid plug, hollow plug, mechanical plug, hydraulic plug, or project-specific plug arrangement |
Sealing Options |
Primary packing, secondary seal, O-ring, metal-to-metal seal, PTFE, graphite, elastomer, or application-specific sealing package |
Documentation |
Material certificates, hydrotest records, dimensional reports, pressure test records, NDE reports, and project data sheets upon request |
Material Options
Construction materials are selected based on the process fluid, pressure, temperature, corrosion risk, sour service requirements, and project piping class. Common materials include carbon steel, low-temperature carbon steel, stainless steel, duplex stainless steel, super duplex stainless steel, nickel alloys, titanium, and other project-specific alloys.
| Material Grade | Full ASTM / ASME Material Code |
Typical Use / Remarks |
A105 / A105N |
ASTM A105 / A105M; ASME SA-105 / SA-105M – Standard Specification for Carbon Steel Forgings for Piping Applications |
Access fitting bodies, flanges, bosses, and forged pressure-retaining parts for general service. A105N indicates normalized condition when specified. |
A350 LF2 |
ASTM A350 / A350M; ASME SA-350 / SA-350M Grade LF2 – Standard Specification for Carbon and Low-Alloy Steel Forgings, Requiring Notch Toughness Testing for Piping Components |
Low-temperature service where impact-tested carbon steel forgings are required. |
F304 / F304L |
ASTM A182 / A182M; ASME SA-182 / SA-182M Grade F304 / F304L – Standard Specification for Forged or Rolled Alloy and Stainless Steel Pipe Flanges, Forged Fittings, and Valves and Parts for High-Temperature Service |
Stainless steel access fitting parts, plugs, probe holders, and coupon holders for general corrosion-resistant service. |
F316 / F316L |
ASTM A182 / A182M; ASME SA-182 / SA-182M Grade F316 / F316L – Standard Specification for Forged or Rolled Alloy and Stainless Steel Pipe Flanges, Forged Fittings, and Valves and Parts for High-Temperature Service |
Preferred stainless steel option for chloride, marine, chemical, produced water, and general corrosion monitoring service. |
F51 |
ASTM A182 / A182M; ASME SA-182 / SA-182M Grade F51 – Duplex Stainless Steel Forgings, commonly UNS S31803 / S32205 |
Duplex stainless steel for higher strength and improved chloride stress corrosion resistance. |
F53 |
ASTM A182 / A182M; ASME SA-182 / SA-182M Grade F53 – Super Duplex Stainless Steel Forgings, UNS S32750 |
Super duplex stainless steel for seawater, offshore, and severe chloride corrosion applications. |
F55 |
ASTM A182 / A182M; ASME SA-182 / SA-182M Grade F55 – Super Duplex Stainless Steel Forgings, UNS S32760 |
Super duplex stainless steel for high-strength and highly corrosive applications. |
Alloy 625 |
ASTM B564; ASME SB-564 UNS N06625 – Standard Specification for Nickel Alloy Forgings |
Nickel alloy for sour service, seawater, acid gas, and aggressive chemical environments. |
Alloy 825 |
ASTM B564; ASME SB-564 UNS N08825 – Standard Specification for Nickel Alloy Forgings |
Nickel-iron-chromium alloy for acidic, sour, and severe process environments. |
Hastelloy C276 |
ASTM B564; ASME SB-564 UNS N10276 – Standard Specification for Nickel Alloy Forgings |
High corrosion resistance for aggressive chemical and chloride-bearing environments. |
Material selection note: Final material selection should be confirmed based on corrosion mechanism, process chemistry, sour service requirements, chloride level, temperature, pressure, weldability, galvanic compatibility, impact testing requirements, and the client-approved piping specification.
Why Choose Our Corrosion Access System?
- Improved asset integrity: Supports corrosion monitoring programmes by enabling coupon exposure and probe measurement at critical process locations.
- Online monitoring capability: Enables retrieval and replacement of monitoring devices using suitable service valves and retrievers without full system shutdown, where permitted by procedure.
- Flexible device compatibility: Supports coupon holders, ER probes, LPR probes, hydrogen probes, erosion probes, sampling devices, and injection accessories.
- Pressure-retaining design: Built for sealing reliability, mechanical integrity, and compatibility with pressurised pipeline and vessel service.
- Project-ready documentation: Available with material traceability, testing, inspection, and certification packages.
Ordering Information
To request a quotation, please provide the following information: line size, pipe schedule, installation orientation, process fluid, design pressure, operating pressure, design temperature, operating temperature, connection type, access fitting type, plug type, coupon type, probe type, insertion length, required material, sealing material, applicable standards, sour service requirement, inspection requirements, and documentation package.
Relevant Industry Standards and Codes
The applicable standards for corrosion access fittings, coupon holders, and probes depend on the project specification, operating pressure, temperature, material selection, sour service requirements, hazardous area classification, and whether the assembly is supplied as a pressure-retaining fitting, valve assembly, or instrumented monitoring device.
| Standard / Code | Typical Relevance |
ASME B31.3 – Process Piping |
Common reference for process piping design, fabrication, inspection, examination, testing, and pressure-retaining components in process plants. |
ASME B16.5 – Pipe Flanges and Flanged Fittings |
Applicable where access fittings are supplied with RF or RTJ flanged connections. |
ASME B16.11 – Forged Fittings, Socket-Welding and Threaded |
Relevant for threaded, socket-weld, or forged fitting components used in access fitting assemblies. |
ASME B16.34 – Valves |
Relevant to pressure-temperature rating and design requirements for service valves, DBB valves, and isolation valves. |
API 6D / ISO 14313 |
May apply when pipeline valves or pipeline service valve assemblies are specified. |
API 598 |
Common reference for inspection and pressure testing of valves supplied with the access fitting system. |
ASTM G1 |
Practice for preparing, cleaning, and evaluating corrosion test specimens after exposure. |
ASTM G4 |
Guide for conducting corrosion coupon tests in field applications. |
ASTM G31 |
Guide for laboratory immersion corrosion testing of metals, useful for coupon evaluation methodology. |
ASTM G59 |
Practice for conducting potentiodynamic polarisation resistance measurements, relevant to electrochemical corrosion testing. |
ASTM G96 |
Guide for online monitoring of corrosion in plant equipment using electrical and electrochemical methods. |
ASTM / ASME Material Standards |
Applicable for construction materials including carbon steel, low-temperature carbon steel, stainless steel, duplex, super duplex, and nickel alloys. |
NACE MR0175 / ISO 15156 |
Applicable for metallic materials used in H2S-containing sour oil and gas production environments. |
NACE MR0103 |
Applicable for metallic materials in sour petroleum refining environments where specified. |
AMPP / NACE Corrosion Monitoring Guidance |
May be referenced for corrosion monitoring practice, coupon exposure, probe use, and integrity management requirements. |
EN 10204 Type 3.1 / 3.2 |
Material certification reference for traceability and inspection documentation. |
IEC / ATEX / IECEx Requirements |
May apply to electrical probes, transmitters, junction boxes, or instruments installed in hazardous areas. |
ISO 9001 |
Quality management system reference for manufacturing, inspection, documentation control, and traceability. |
Online retrieval note: Corrosion access systems intended for insertion or retrieval under pressure should be used only with compatible service valves, retrievers, pressure equalisation tools, bleed arrangements, and approved operating procedures.
Note: Final design and standard selection should be confirmed against the client specification, design code, local statutory requirements, fluid service, pressure rating, hazardous area classification, sour service requirements, and project quality plan.
Need a corrosion monitoring access solution?
Send us your process data sheet, piping specification, corrosion monitoring philosophy, or project requirements and our team will recommend a suitable access fitting, coupon holder, probe, service valve, or retriever configuration.