LittleInch,
Both of the automated valves at inlet of rupture disks have a common actuator and are connected by a mechanical link. When one valve opens, the other one closes simultaneously. This change over happens quite rapidly when we switch to the redundant unit for maintenance, etc.
The...
This rupture disk-relief valve combination is installed on the outlet line of a heater (steam on shell side), and process stream is all liquid. I'd consider that the real purpose of the relief valve (with a D orifice) is thermal relief, but the datasheet says fire scenario. I guess that due to...
In our plant, there is a 1" rupture disk combination with a relief valve, along with a redundant unit, which is procured for gas/vapor service (i.e., fire scenario). At a few times when the rupture disk is switched to the redundant unit, the redundant rupture disk bursts as soon as it’s taken...
Poli60,
Thank you for responding on my questions. The plant which has this flare system is a complex plant with a couple of different sections. I have combined the fire relieving capacity of all pressure safety valves in the plant to calculate the total load to flare. This means that I'm...
I have been working on a flare system to which the PSVs’ relief load due to fire scenario is exceeding the capacity of the flare system (due to an expansion in the plant). I know that using API's methodology for relief load calculation normally gives smaller relief load as compared to NFPA's...
TD2K,
Thanks for your reply. This is an existing column which I'm retrofitting with a HIPS system. The intention is to create room for additional relief load from a plant expansion, which would otherwise require an expensive expansion of the relief system.
Can you also guide me that when I...
All,
I'm currently working on reducing the relief load from a distillation column to the flare system by installation of a HIPS (or HIPPS) on the steam valve to the column. My understanding was that after installation of HIPS, I have the replace the pressure safety valve by a smaller one which...
I'm currently working on designing an absorber in Aspen Plus. For the required absorption, Aspen is telling me that I need 4 stages. Can someone guide me how to convert the 4 stages to the height of a packed bed or of a trayed column? Are there any good correlations for this purpose?
On a...
All,
Can you guide me whether pressure safety valves are needed on steam/condensate drums or on steam side of heat exchangers while there are no flammable liquid vessels in the vicinity? Alternatively, does this requirement change when there is a flammable liquid vessel nearby? What is the...
