We are all aware of the ASME Sec VIII, as an international Code for designing pressure vessels, but have we ever thought that despite the code being not mandatory why it is a common trend in Oil and Gas. If we look up in history of incidents that led to safety hassles, in most cases ‘Improper design’ caused unknown pressure differential that was dangerous and led to fatal consequences.
Considering these impacts in the past, many associations developed guidelines to design pressure vessels. Some guidelines are followed internationally and some are followed country wise. These guidelines are termed as Codes and Standards.
Amongst the available codes (ASME Sec VIII, PD 5500, EN 13445 3, IS 2825) ASME is the most favored code in the Oil & Gas Industry.
The reason for such universal acceptance of ASME Sec VIII is essentially due to the following parameters:
- ASME Sec VIII is one of the safest code and the safety margin is also high compared to other design codes.
- ASME codes are updated every year based on the feedback received from the users and based on current industry scenario.
- ASME being the largest committee for codes also ensures better and reliable experience. Interpretation of any code is always a complicated issue for engineers wherein the support provided by ASME through prompt replies helps the engineers to understand the technical aspect and expedites the engineering process.
Additional Information regarding Pressure Vessels & ASME Sec VIII
Pressure Vessel: A pressure vessel is a closed container designed to hold gases or liquids at a pressure substantially different from the ambient pressure.
Pressure ranges in ASME Sec VIII code:
Pressure range starts from 15 PSI to 3000 PSI can be designed as per ASME Sec VIII Division 1. Pressure range starts from 3000 PSI to 10,000 PSI can be designed as per ASME Sec VIII Division 2. Pressure range over 10,000 PSI can be designed by ASME Sec VIII Division 3.
ASME (American Society of Mechanical Engineers) Stamps – Ready Reckoner
- A – Field Assembly of Power Boiler
- E – Electric Boilers
- H – Heating Boilers, steel plate or cast iron sectional
- HV – Heating Boiler safety valve
- HIW – Lined portable water heaters
- M – Miniatures Boilers
- N – Nuclear power plant components
- NPT – Nuclear power plant component particles
- NA – Nuclear power plant installation/Assembly
- NV – Nuclear power plant safety valves
- PP – Pressure piping
- RP – Reinforced plastic pressure vessels
- RTP – Reinforced Thermoset plastic corrosion resistant equipment
- S – Power boilers
- U1, U2, U3 – Pressure vessels
- UD – Rupture disc devices
- UM – Miniature Pressure vessels
- UV3 – High pressure vessel safety valves
- V – Boiler safety valve
Till 2008 the ASME U-stamp will be as shown below,
From 2009 the ASME stamping has been changed as shown below.
ASME is the stamp and U is the designator.
Designator shall be changing based on the application and design like A, E, H, HV, M, N, NPT, NA, NV, PP, RP…etc.