LDAR Vs Piping Material Classes

[techv]

Would appreciate your help in guiding me with standard practice in the Industry for our new petrochemical plant:

Our project has special specifications for Leak Detection and Repair (LDAR) program which basically is about field monitoring requirements for controlling fugitive emissions. I guess the regulated components (Pumps/Compressors/Valves/Flanges etc)shall be provided with appropriate material for their seals/packing/gaskets to meet the Fugitive Emission limits of 10000/500 ppm, as applicable. We are unclear whether our Specifications (for Piping Material Classes-PMCs) are suitable to meet the limits.

Pls assist me in the following:

1) How these requirements are normally taken care during design??
2) Are special materials are required for seals/packing/gaskets to meet the emission limits?? I assume the components in volatile hydrocarbon service would need better material compared to those in water service. Bear with me- I am not Piping Specialist!!
2) If so, do PMCs / TReqs need to be taken care to ensure procuring of these??

Your responce ASAP will be highly appreciated.

Thanks
TechV

 

[dcasto]

For example, a 1/16" "graphite impregnated paper gasket" is suitable for gas at pressures up to 5 psig, but it would certainly leak at 200 psig. A teflon material at 100 F is OK, but at 500F it would melt.

As a performance based standard, you decide what materials you will use and then install only those materials for the conditions, this way you don't have to have to use the same exact sealing materials everywhere. This also gives you some control on the economic impact to your company. If material "A" lasts for 1 year before it leaks and it costs 10% of material "B" that is 10 times the price, then "A" is the most economical, but with LDARS testing, "B" gets it's inspection time reduced and saves money, so now "B" is the better economical solution.

 

[techv]

Decasto, Thanks for that insight.

With internal deliberations and some Valves supplier info, It is understood that the valves normally supllied do meet emission limirs upto 100 ppm also. It is getting clear that the 10000/500 ppm shal be strictly considered as work practice standards and not as source limits. But I guess, we still need to ask suplliers to gurantee for that. Anybody in design/consultancy firm may through more light on this.