Isolating a pressure relief device during operation is only permitted under very specific circumstances and with strict safety procedures. In most cases, isolation is prohibited due to the critical safety function of these systems. Temporary isolation is exclusively permitted when alternative protection is active and all legal requirements are complied with.
What is a pressure relief device and why is isolation so crucial?
A pressure relief device protects pressure vessels against dangerous pressure buildup by releasing excess pressure when the maximum allowable working pressure is exceeded. This safety valve maintenance prevents explosions and catastrophic damage to equipment and injury to personnel.
Isolation of pressure relief protection during operation brings significant risks. Without functioning pressure protection, a pressure vessel can explode in case of control equipment failure or unexpected pressure rise. Dutch legislation, based on the European pressure equipment directive, requires that pressure vessels are always provided with adequate protection during use.
Legal requirements stipulate that pressure system safety must never be compromised without explicit permission from competent authorities. Violation of these rules can lead to fines, shutdown of installations and criminal prosecution in case of accidents.
When may you isolate a pressure relief device during operation?
Isolation of a pressure relief device during operation is only permitted when redundant protection is active and the pressure level remains well below the maximum allowable working pressure. This requires prior approval from a recognized expert and strict monitoring.
Specific conditions for permitted isolation include:
- Presence of a second, independent pressure relief device
- Maximum 70% of the allowable working pressure during isolation
- Continuous monitoring by qualified personnel
- A written work permit with risk analysis
- A limited isolation duration (usually maximum 8 hours)
Absolutely prohibited situations for isolation of a pressure relief device are systems without redundant protection, processes with unpredictable pressure rises and installations where personnel safety directly depends on the primary protection.
Which safety procedures are mandatory for isolation of pressure relief protection?
Safe isolation of pressure relief protection requires a structured protocol with risk analysis, alternative safety measures, clear communication and complete documentation. Each step must be performed by qualified personnel according to established procedures.
The mandatory safety protocol includes:
- Perform risk analysis – Identify all possible hazards and consequences.
- Activate alternative protection – Ensure redundant pressure relief protection.
- Request work permit – Obtain written permission from an authorized person.
- Reduce pressure – Reduce system pressure to a safe level.
- Establish continuous monitoring – Install additional pressure gauges and alarms.
- Record communication – Inform all involved parties about the isolation status.
- Maintain documentation – Register all actions and observations.
Communication procedures require clear marking of isolated equipment, briefing of all shift teams and a logbook for pressure relief valve maintenance.
What are the alternatives to isolation during operation?
Practical alternatives to isolation during operation include planned shutdowns for maintenance, temporary bypass systems with mobile pressure relief protection, redundant protection systems and online maintenance techniques that do not require isolation.
Effective alternatives are:
- Planned maintenance stops – Combine pressure relief valve maintenance with regular shutdowns.
- Mobile bypass systems – Temporary pressure relief protection during maintenance.
- Redundant protection – Install multiple, independent pressure relief devices.
- Online inspection techniques – Use non-destructive testing methods during operation.
- Preventive maintenance – Regular inspection prevents acute need for isolation.
Online maintenance techniques, such as ultrasonic examination and endoscopy, make it possible to assess the condition of components for safe maintenance of pressure relief protection without isolation. These methods reduce the need for risky isolation procedures.
How Presscon helps with safe maintenance of pressure relief protection
We offer complete support for safe maintenance of pressure relief protection, from risk analysis to execution of maintenance work. Our expertise in pressure vessel systems and years of experience ensure reliable, safe solutions.
Our concrete support includes:
- Risk analysis and safety consultancy – Assessment of isolation procedures and alternatives.
- Design of redundant protection systems – Implementation of backup pressure relief protection.
- Mobile bypass solutions – Temporary systems for safe maintenance.
- Online inspection services – Condition monitoring without operational interruption.
- 24/7 maintenance service – Quick response for acute maintenance needs.
- Training and certification – Training your technicians in safe procedures.
Do you have questions about safe isolation of pressure relief protection or would you like advice about alternatives for your specific situation? For explosive atmospheres we offer specialized ATEX vacuum pressure relief device solutions. Contact us for professional advice and customized solutions that guarantee safety and business continuity.
Frequently Asked Questions
How long does the process take to get permission for isolation of a pressure relief device?
Obtaining permission for isolation requires at least 24-48 hours preparation for the risk analysis, work permit and approval by a recognized expert. In complex situations this process can take several days, especially if additional safety measures need to be installed.
What happens if the redundant protection fails during isolation of the primary pressure relief device?
If redundant protection fails, the process must be immediately shut down and the primary protection must be restored. This requires an emergency procedure with direct pressure reduction, evacuation of personnel from risk areas, and restoration of the original protection configuration within a maximum of 30 minutes.
What costs are associated with implementing a redundant protection system?
The costs for redundant pressure relief protection vary from €5,000 to €50,000 depending on system complexity, pressure class and installation requirements. This investment is often more advantageous than repeated production interruptions for maintenance and significantly reduces operational risks.
How often must an isolated pressure relief device be checked during maintenance?
During isolation, the system pressure must be checked every 15 minutes, with continuous monitoring via alarm systems. The redundant protection requires a function test every hour, and all findings must be documented in the isolation logbook by qualified personnel.
Can online inspection techniques completely replace what traditional maintenance with isolation achieves?
Online inspection techniques such as ultrasonic examination and endoscopy can replace 80-90% of traditional inspections, but mechanical maintenance of seats, springs and seals still requires physical access. The combination of both methods optimizes safety and maintenance efficiency.
What sanctions does a company risk with unlawful isolation of pressure relief protection?
Unlawful isolation can lead to fines of €10,000 to €100,000 per violation, direct shutdown of the installation by the Labour Inspectorate, and in case of accidents possible criminal prosecution of responsible persons. Insurance claims may also be rejected in case of proven rule violation.
How do you train personnel in recognizing situations where isolation is absolutely prohibited?
Effective training combines theoretical knowledge of pressure equipment rules with practical simulations of emergency situations. Personnel must learn to identify critical systems, recognize pressure patterns, and use decision trees for isolation decisions. Annual retraining and competency tests are mandatory for certification.