Safety & Pressure Relief Valves

Safety and pressure relief valves should be taken very seriously.

They must always accurately respond to system conditions and prevent catastrophic failure when other instruments and control systems fail to adequately control process limits.

Unfortunately, because of the lack of knowledge and disappearing expertise worldwide, the quality of selection and operation of pressure relief valves is often insufficient.

This possibly jeopardizes the safety of each of us, living or working in the neighborhood of a process plant.

Proper sizing, selection, manufacture, assembly, test, installation and maintenance of a pressure relief valve are all critical to obtaining maximum protection.

Designed around a series of practical examples which we work through to a solution, this valuable course is an essential guide to a complete understanding of construction details and functioning of relief and safety valves.

This understanding is a pre-requisite for the proper sizing, selection, assembly, test, installation and maintenance of pressure relief valves.

The course presents reference data, technical recommendations and field observations based on our many years of experience in sizing, selecting, testing, installing and operating pressure relief valves.

The basic formulae and capacity correction factors contained in this course reflect current state-of-the-art pressure relief valve sizing technology.

Typical valve sizing examples have been included to assist in understanding how specific formulae are applied.

Useful technical data covering terminology, standards, codes, basic design, sizing and selection information, are presented in an easy to use format.

Reference is made to :

• ASME Boiler and Pressure Vessel Code, Section VIII, Pressure Vessels

• API Recommended Practice RP520

This course also cautions the piping designer, the process engineer and any user of safety valves, that the performance of a properly sized and selected pressure relief valve, can be severely compromised when used in conjunction with improper companion piping or incorrect handling and installation.

Pressure relief valve installation guidelines and their rationale, as well as some precautions, are offered to ensure optimum performance and safety.

Now, while it is obviously impossible to address every installation mistake ever made, we have included a valuable summary of the most frequent installation mistakes encountered in the field.

We are confident that this valuable course will help you contribute to the safety of your facility, your fellow workers and yourself.

• Chemical, Process, Petroleum Engineers
• Design Engineers
• Piping Engineers
• Plant Engineers
• Mechanics
• Safety inspectors

1. It is important to always remember that a pressure relief valve is a safety device employed to protect pressure vessels or systems from catastrophic failure. With this in mind, the application of pressure relief valves should be assigned only to fully trained personnel and be in strict compliance with rules provided by the governing Codes and Standards

2. Pressure relief valves must be sized, selected and installed by those who have complete knowledge of:

   • The pressure relieving requirements of the system to be protected

   • The environmental conditions particular to that installation

3. Pressure relief valves sizing and selection is the responsibility of:

   • The process engineer

   • The user of the system to be protected

4. Sizing and selection of pressure relief valves should not be based on arbitrarily assumed conditions or incomplete information. Merely having a mandatory safety valve installation does not make a system safe