By recuperator, I presume that you are referring to a tubular air-to-air or gas-to-air exchanger operating at essentially atmospheric pressure on both sides.
If that is the case, there are no specific industry standards that I am aware of that would apply. Basically, such an exchanger would be designed per the project specifications, which need to be custom taylored to the specific application. Here are a few points to consider in writing the spec:
1. Materials of construction for all major components.
2. Insulation (if any) - type, thickness, lagging, etc.
3. Obvious performance specs, including maximum allowable pressure drops on both sides (very important). Include operating pressures of both fluids.
4. Provisions for differential thermal expansion.
5. Some definition of the importance (or lack thereof) of leakage from the higher pressure side to the lower pressure side. In some applications itis very important to have no leakage. In others, some leakage is OK.
