Pressure Vessel Regulation in Gas and Oil Infrastructure

Pressure vessels are central to the oil and gas industry. Whether storing hydrocarbons, facilitating chemical reactions, or separating process streams, these vessels operate under extreme pressure and temperature conditions.

Inconsistent or imprecise pressure control can lead to safety risks, process inefficiencies, equipment damage, and regulatory non‑compliance. Over‑pressurization risks vessel failure or activation of safety relief systems, while under-pressurization can disrupt downstream processes or cause phase separation issues. The pressure control system must therefore be considered a critical part of the vessel’s design.

Many plants still rely on pneumatic control systems built around mechanical regulators and binary solenoid valves. While functional, these setups are inherently limited. They cannot dynamically adjust to fluctuations in supply pressure, ambient temperature, or source gas composition.

As a result, when pressure drifts, valve behavior becomes unpredictable, introducing errors and instability downstream. Systems without proportional valves that rely on basic pneumatic controls also create operational delays when switching between feed gases or process lines, increasing the risk of pressure surges, flow interruptions, and contamination during transitions. These shortcomings can negatively impact the performance of compressors, separators, and downstream instrumentation tied to the vessel.

In systems with proportional and electronic control, a regulatory obstacle arises: electronics have the potential to produce sparks and must be rerouted or enclosed in bulky protective housings. This drives up cost, increases maintenance complexity, and consumes valuable space in already crowded plant environments.

The challenge for the process engineer then, is to design a system that balances responsive, precise pressure control with compliance to safety standards, particularly in highly regulated hazardous zones. This balance must account not only for the pressure vessel itself, but also for the critical systems that rely on it.

When a North American gas company set out to design a new pressure control system, they integrated an intrinsically safe IS-PRO™ dual-valve pressure controller (PCD) to maintain vessel pressure within a Class I, Division 1 explosive location.

In this configuration, the IS-PRO™ PCD supplied pilot pressure to a dome‑loaded pressure regulator (DLPR) — a type of regulator that uses a pilot signal, rather than a mechanical spring, to control back pressure. This setup offers faster response times, greater accuracy, and better stability across varying flow rates, making it ideal for high‑performance and high‑risk environments like oil and gas facilities.

By adjusting the pilot pressure proportionally, the ISPCD enabled high‑resolution, closed‑loop control of the DLPR. This allowed for automated pressure regulation without introducing spark risks in a Class I, Division 1 hazardous location. The system was configured to maintain vessel pressure between 0 and 100 PSIG (0 to ~6.9 bar), with inlet pressures ranging from 120 to 150 PSIG (8.3 to 10.3 bar). Exhaust was vented to atmosphere, and the ambient temperature ranged from 20 to 115 °F (−6.7 to 46.1 °C).

The ISPCD’s precise control capabilities and compatibility with digital setpoints made it particularly well‑suited for use with DLPRs, enabling reliable pressure management while ensuring compliance with intrinsically safe requirements.

The IS‑PRO’s ability to measure absolute, gauge, or differential pressure — and communicate data via digital or analog signals — allowed seamless integration into the facility’s existing SCADA infrastructure. This enabled proportional control and accurate pressure measurement, improving both vessel safety and overall system efficiency.

In critical oil and gas operations, where pressure vessels must perform reliably under volatile conditions, precise pressure control is non‑negotiable. By integrating the IS‑PRO™ dual‑valve pressure controller, the engineer replaced manual, static control with automated, closed‑loop control. This ensured consistent pressure regulation and resulted in a more efficient process aligned with the demands of modern oil and gas infrastructure.