komposites
Materials
- Nov 28, 2012
- 15
I'm looking over the ASME BPVC, Mandatory Appendix 8 for Class 3, Gas Hydrogen Vessels (Carbon Fiber Pressure Vessel with Plastic Liners).
I have a question on the epoxy resin requirements.
8-300.4.1b (RESINS SYSTEM-MATERIAL REQUIREMENTS) states that "resin supplier shall CERTIFY, for each batch shipped, the value and limits required by the specification of the properties identified in Table 8-300.4.1-1 (Basically, viscosity, epoxide equivalent, and specific gravity).
My questions are:
1) Do most ASME Inspectors consider the word "CERTIFY" the same as (a) "Test every time for each batch" or (b) "Test at a regular frequency as chosen by the resin manufacturer, and just provide a piece a paper that says it is CERTIFIED without testing it for every batch". This also applies to the entirety of ASME Code when it says "certify". I want to be certain, so I hope the answer will come from an ASME inspector or someone that deals with inspectors routinely for this type of vessel.
2) Can you use the epoxide equivalent provided by the base resin manufacturer (Dow, GE, BASF, Dupont, etc), then adjust the wt% appropriately based on added mass of other additives or fillers used to modify the epoxy?? It seems wasteful to repeat the same test that was already performed on the BASE RESIN. I don't feel that the epoxide equivalent would change.
-K
I have a question on the epoxy resin requirements.
8-300.4.1b (RESINS SYSTEM-MATERIAL REQUIREMENTS) states that "resin supplier shall CERTIFY, for each batch shipped, the value and limits required by the specification of the properties identified in Table 8-300.4.1-1 (Basically, viscosity, epoxide equivalent, and specific gravity).
My questions are:
1) Do most ASME Inspectors consider the word "CERTIFY" the same as (a) "Test every time for each batch" or (b) "Test at a regular frequency as chosen by the resin manufacturer, and just provide a piece a paper that says it is CERTIFIED without testing it for every batch". This also applies to the entirety of ASME Code when it says "certify". I want to be certain, so I hope the answer will come from an ASME inspector or someone that deals with inspectors routinely for this type of vessel.
2) Can you use the epoxide equivalent provided by the base resin manufacturer (Dow, GE, BASF, Dupont, etc), then adjust the wt% appropriately based on added mass of other additives or fillers used to modify the epoxy?? It seems wasteful to repeat the same test that was already performed on the BASE RESIN. I don't feel that the epoxide equivalent would change.
-K