Flanged joints are a necessary reality in petrochemical plants: they enable modular construction, maintenance access, and tie-ins across process units. At the same time, they remain one of the most recurrent points of loss of containment because they combine pressure, temperature cycles, vibration, and chemical compatibility constraints in a single interface. A small leak can start as a subtle, intermittent event and evolve into a persistent emission, corrosion hotspot, insulation damage, or an unplanned shutdown for investigation and repair.

Traditional approaches rely on periodic inspections, operator rounds, and portable detectors. These methods work, but they create blind spots between routes, especially in congested pipe racks, elevated galleries, and areas with limited access. In addition, when a smell or visible indication is reported, the response often becomes reactive: isolate the area, mobilize maintenance, verify with handheld instrumentation, and coordinate with operations. The goal of this solution is to convert flange leak risk into a continuously observable condition with clear escalation paths and integration into plant workflows.

What this solution solves

This solution addresses early detection and operational management of leaks at flanged joints in petrochemical environments. The main problem is not only identifying that a leak exists, but doing it early enough to control exposure, minimize secondary damage, and prevent the investigation process from interrupting production more than necessary.

When flange integrity is managed only through periodic checks, plants face three structural limitations: (1) time gaps between inspections, (2) uncertainty about leak onset and duration, and (3) delayed coordination between Operations, Maintenance, and EHS. This can translate into avoidable work orders, emergency callouts, temporary process derates, and increased risk during troubleshooting.

Nasatech’s approach is built for repeatable deployment: a sensor layer suited for flange-perimeter detection, an MQTT-native NTX device for edge acquisition and secure publishing, managed field connectivity via Nasatech LINK, and an optional platform layer for alerts, visualization, and integration into existing systems.

How it works

Signal capture at the flange starts with fit-for-purpose sensing around the joint. Depending on the fluid family and area constraints, the sensing strategy may include hydrocarbon gas detection (point sensing near likely leak paths), chemical vapor detection, or complementary indicators such as local temperature anomalies or acoustic patterns. The sensing is engineered to detect deviations from baseline conditions and to avoid nuisance alarms by using stable thresholds, time persistence, and context (for example, planned venting or maintenance activities).

Sensor/Instrumentation → NTX device: sensors are wired to a Nasatech NTX edge gateway/data logger (generic NTX field unit) installed near the monitoring zone, typically at the skid, pipe rack section, or local junction box level. The NTX device acquires the measurement signals, applies first-level logic (filtering, validation, health checks), timestamps events, and publishes data using MQTT natively. This preserves a consistent data model for downstream systems and supports a Unified Namespace (UNS) approach when the plant is adopting it.

NTX device → Nasatech LINK: the NTX publishes securely through Nasatech LINK, the managed connectivity service. LINK supports low-power cellular connectivity as a default option for distributed assets and complex pipe rack zones where plant network extension is not practical. Where site policy allows, the same architecture can be deployed over plant Ethernet or other approved OT connectivity, while keeping the same MQTT-native behavior at the edge.

Nasatech LINK → Nasatech CORE Platform (optional): CORE provides robust visualization, alerting, device fleet management primitives, and integration endpoints. CORE is designed as an open, scalable platform layer: the plant can use it as the operational interface for this use case, or treat it as an integration hub that forwards events and time-series data to the customer’s preferred tools.

CORE Platform (optional) → Customer integration: data and alarms can be integrated into an MQTT broker, a UNS hierarchy, a SCADA/HMI environment, a CMMS for work order initiation, or upstream systems aligned with ISA-95 (for example, maintenance and operations coordination across levels). The solution is compatible with Purdue-model segmentation by keeping edge acquisition in OT zones and controlling northbound flows through defined interfaces.

In potentially classified areas, the sensing and installation approach is designed with appropriate engineering caution. Final hardware selection and installation methods should follow site classification requirements; the solution can be implemented using components and mounting practices compatible with such environments without making assumptions about certifications in advance.

Nasatech components

Nasatech NTX (MQTT-native edge) is the field device layer. For flange leak detection, NTX acts as the local acquisition and publishing node: it interfaces with gas/vapor sensors and related instrumentation, performs input validation, and produces consistent telemetry and event topics over MQTT. The goal is a repeatable edge pattern: predictable wiring, predictable topic structure, predictable commissioning steps, and predictable integration behavior across units and plants.

Nasatech LINK (managed connectivity) is the connectivity service that reduces deployment friction in complex petrochemical layouts. LINK supports cellular low-power connectivity as a practical default for distributed monitoring points. It is particularly useful when extending the plant network is expensive, slow, or constrained by policy. LINK also supports operational visibility for connectivity status so that data gaps are managed explicitly rather than discovered after an incident.

Nasatech CORE Platform (optional) is the open and robust platform layer. It can host dashboards, alarm routing, and event histories for investigations, while exposing integration interfaces so the plant can keep its system-of-record strategy. CORE is intentionally optional: plants with existing historians, SCADA alarm management, or enterprise event buses can integrate directly via MQTT and APIs while still benefiting from NTX and LINK.

Integration and scalability

This solution is designed to scale from a small set of high-risk flanges to a plant-wide monitoring program without changing the core architecture. The scaling logic is built around three principles: standardized data models, controlled network boundaries, and integration patterns that align with modern OT/IT convergence.

IT/OT separation and Purdue alignment: NTX devices and sensors reside close to the process in OT zones. Northbound data exchange is designed to be intentional and minimal: publish telemetry and events, avoid unnecessary inbound commands, and keep management access controlled. This supports Purdue-model zoning by maintaining a clear separation between control networks and monitoring/integration layers. Where a site uses an ISA-95-aligned structure, leak events can be routed so that Operations and Maintenance receive consistent context without bypassing established governance.

MQTT-first integration and UNS readiness: because NTX is MQTT-native, the solution fits naturally into a broker-based architecture. Plants implementing a Unified Namespace can map flange monitoring topics into a consistent hierarchy (asset → location → measurement → event), enabling easy consumption by analytics, maintenance applications, and visualization tools. Where UNS is not yet in place, the same MQTT streams can be bridged to SCADA, historians, or middleware through standard connectors.

APIs and event routing: CORE (optional) and integration endpoints allow events to trigger downstream workflows such as CMMS notifications, incident management, or maintenance planning. The intent is operational clarity: when a leak is suspected, the right team receives the right signal with traceability (what, where, when, how persistent), not just a generic alarm.

Cybersecurity by design: communications use encrypted transport (TLS) for MQTT where applicable, with controlled authentication and access policies. Device onboarding and access are managed to reduce unauthorized interaction. The architecture supports segmentation policies, with clear demarcation between field devices, connectivity services, and enterprise consumers.

Operational benefits

Earlier awareness of loss of containment helps shift response from reactive troubleshooting to controlled intervention. Instead of discovering leaks only during rounds or after visible indicators, the plant can detect persistent deviations, correlate them with operating conditions, and prioritize response by severity and duration.

Improved traceability for investigations comes from time-stamped data and event histories. Teams can review when a signal started, whether it is intermittent, and whether it correlates with start-ups, load changes, temperature cycles, or vibration events. This supports better root-cause discussions and more targeted maintenance actions.

Reduced operational disruption is achieved by replacing uncertainty with actionable alerts. When an operator report triggers a hunt for a leak, the effort can be large. With monitored joints, maintenance can be directed to specific locations and time windows, while Operations can make informed decisions about isolations and safe work planning.

Structured maintenance workflows are enabled through integration. Leak events can be routed into CMMS as condition-driven notifications, tagged to assets, and managed with consistent priority rules. This supports standard reliability practices without forcing a new toolchain.

Fleet-level consistency comes from the NTX pattern and LINK connectivity: the same commissioning and data approach can be repeated across units, which helps when plants expand the program from critical flanges to broader coverage.

Application scenarios

1) High-consequence flange groups on critical lines: deploy sensors on flanges around pumps, compressors, and key block valves where leakage increases operational risk and complicates maintenance access. Use persistent-alarm logic and escalation routing to ensure fast response when a trend becomes stable.

2) Pipe racks with limited accessibility: monitor long runs where inspection frequency is constrained by access permits or congestion. Cellular connectivity via LINK supports deployment without depending on extended plant networking.

3) Areas with insulation and corrosion exposure: flange leaks under insulation can evolve into corrosion hotspots or insulation damage. Monitoring provides early indication that can trigger targeted inspection rather than broad removal campaigns.

4) Turnaround verification and post-maintenance monitoring: after gasket replacement or flange re-torque activities, temporary monitoring can validate stability during the first operating cycles and reduce the risk of returning to reactive mode.

Request a quotation

To prepare a quotation for leak detection in flanged joints, Nasatech structures the proposal around repeatable building blocks: sensing approach per fluid family, number of monitoring points, NTX field units, connectivity via Nasatech LINK (cellular low-power by default), and optional Nasatech CORE Platform for visualization and alerting.

Provide the following to scope accurately:

  • Unit or area to cover (process unit, pipe rack section, or skid) and approximate number of target flanges
  • Fluid type(s) and typical operating conditions (pressure/temperature range)
  • Area constraints (access, mounting options, potential classified zones, power availability)
  • Preferred integration targets (MQTT broker/UNS, SCADA, CMMS, ERP, API/webhooks)

Nasatech will return a clear architecture, deployment bill of materials at a solution level, and an integration outline aligned with your Purdue/ISA-95 governance and cybersecurity requirements.