SAFETY IN THE PLANT
even the harshest operating conditions. Due to such advanced performance characteristics, some rupture discs are now offered with a three-year warranty compared to the traditional 12 months. Concerns on tolerances such as manufacturing/
operating range, temperature and set point have been driving customers to opt for buckling pins in instances where operating as close to the set point as possible is critical. Modern buckling pins typically offer maximum operating pressures of 95% to 98% of the set point. Where original rupture discs didn’t offer such characteristics, leading manufacturers’ reverse- acting discs are available with 3% tolerances and 97% operating ratios; the benefit of these tighter tolerances is that there is a less dramatic effect on the operation of the rupture disc due to temperature changes and in many instances stock can be rationalised, dramatically reducing purchasing costs. Dependent on the application, process mediums and
conditions can vary significantly. Corrosion is a real concern for many customers who want to avoid their investment failing early and increasing long-term costs. For buckling pin relief valves, the pressure relieving part - the pin - is external to the process conditions, meaning relatively cost-effective materials can be used for this component as it will never be in contact with the process media. This ensures low repurchase costs and confidence that the product should not be affected by this problem. The buckling pin valve itself is typically sourced from materials compatible with the process medium, although this is typically limited to carbon or
stainless steel. Although sourcing the valve body in corrosive resistant materials may lead to a high initial investment cost, this is a long-term investment as the valve will typically last the length of the project. Although rupture disc devices are in contact with
the process medium, they can be manufactured from a wide range of highly non-corrosive materials including; graphite, Hastelloy and tantalum. For modern rupture disc designs, in the instance a rupture disc is affected by corrosion, the discs will
Fail-safe installation tools mounted to the flange for correct holder installation
Buckling pin relief
valve - visual indication of pin status
www.engineerlive.com
39
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52